Commission Delegated Regulation (EU) 2015/68 of 15 October 2014 supplementing Regulation (EU) No 167/2013 of the European Parliament and of the Council with regard to vehicle braking requirements for the approval of agricultural and forestry vehicles Text with EEA relevance

• 4.1.4. A tractor electrically connected to a towed vehicle via an electric control line, shall provide a clear warning to the driver whenever the towed vehicle provides the failure information that the stored energy in any part of the service braking system on the towed vehicle falls below the warning level, as specified in point 5.2.4. A similar warning shall also be provided when a continuous failure (> 40 ms) within the electric control transmission of the towed vehicle, excluding its energy reserve, precludes achievement of the prescribed service braking performance of the towed vehicle, as specified in point 4.2.3. The warning signal specified in point 2.2.1.29.2.1 of Annex I shall be used for this purpose.

• 4.1.5. In the event of a failure of the energy source of the electric control transmission, starting from the nominal value of the energy level, the full control range of the service braking system shall be guaranteed after twenty consecutive full stroke actuations of the service braking control device. During the test, the braking control device shall be fully applied for 20 seconds and released for 5 seconds on each actuation. It should be understood that during the above test, sufficient energy is available in the energy transmission to ensure full actuation of the service braking system. This requirement shall not be construed as a departure from the requirements of Annex IV.

• 4.1.6. When the battery voltage falls below a value nominated by the manufacturer at which the prescribed service braking performance can no longer be guaranteed and/or which precludes at least two independent service braking circuits from each achieving the prescribed secondary or residual braking performance, the warning signal specified in point 2.2.1.29.1.1 of Annex I shall be activated. After the warning signal has been activated, it shall be possible to apply the service braking control device and obtain at least the performances prescribed for residual and secondary braking in the case of tractor with maximum design speed exceeding 60 km/h or the performance prescribed for secondary braking in the case of tractor with maximum design speed not exceeding 60 km/h. It should be understood that sufficient energy is available in the energy transmission of the service braking system. This requirement shall not be construed as a departure from the requirement concerning secondary braking.

• 4.1.7. If auxiliary equipment is supplied with energy from the same reserve as the electric control transmission, it shall be ensured that, with the engine running at a speed not greater than 80 % of the maximum power speed, the supply of energy is sufficient to fulfil the prescribed deceleration values by either provision of an energy supply which is able to prevent discharge of this reserve when all auxiliary equipment is functioning or by automatically switching off pre-selected parts of the auxiliary equipment at a voltage above the critical level referred to in point 4.1.6 such that further discharge of this reserve is prevented. Compliance may be demonstrated by calculation or by a practical test. For vehicles authorised to tow a vehicle of category R3b or R4b the energy consumption of the towed vehicle shall be taken into account by a load of 400 W. This point does not apply to vehicles where the prescribed deceleration values can be reached without the use of electrical energy.

• 4.1.8. If the auxiliary equipment is supplied with energy from the electric control transmission, the following requirements shall be fulfilled.

• 4.1.8.1. In the event of a failure in the energy source, whilst the vehicle is in motion, the energy in the reservoir shall be sufficient to actuate the brakes when the control device is applied.

• 4.1.8.2. In the event of a failure in the energy source, whilst the vehicle is stationary and the parking braking system applied, the energy in the reservoir shall be sufficient to actuate the lights even when the brakes are applied.

• 4.1.9. In the case of a failure in the electric control transmission of the service braking system of a tractor equipped with an electric control line according to point 2.1.4.1.2 or 2.1.4.1.3 of Annex I, the full actuation of the brakes of the towed vehicle shall remain ensured.

• 4.1.10. In the case of a failure in the electric control transmission of a towed vehicle, electrically connected via an electric control line only, according to point 2.1.4.1.3 of Annex I, braking of the towed vehicle shall be ensured according to point 2.2.1.17.2.1 of Annex I. This shall be the case whenever the towed vehicle provides the ‘supply line braking request’ signal via the data communication part of the electric control line or in the event of the continuous absence of this data communication. This point shall not apply to tractors which cannot be operated with towed vehicles connected via an electric control line only, as described in point 3.4.

4.2.   Trailers

• 4.2.1. In the case of a single temporary failure (< 40 ms) within the electric control transmission, excluding its energy supply, (e.g. non-transmitted signal or data error) there shall be no distinguishable effect on the service braking performance.

• 4.2.2. In the case of a failure within the electric control transmission (e.g. breakage, disconnection), of at least 30 % of the prescribed performance for the service braking system of the relevant towed vehicle shall be maintained.

Until uniform test procedures have been agreed, the manufacturer shall provide the Technical Service with an analysis of potential failures within the control transmission, and their effects. This information shall be subject to discussion and agreement between the Technical Service and the vehicle manufacturer.

For towed vehicles, electrically connected via an electric control line only, according to point 2.1.4.1.3 of Annex I, and fulfilling the requirements set out in point 2.2.1.17.2.2 of Annex I with the performance prescribed in point 3.2.3 of Annex II, it is sufficient that the provisions of point 4.1.10 of this Annex are invoked, when a braking performance of at least 30 % of the prescribed performance for the service braking system of the towed vehicle can no longer be ensured, by either providing the ‘supply line braking request’ signal via the data communication part of the electric control line or by the continuous absence of this data communication.

• 4.2.3. A failure within the electric control transmission of the towed vehicle that affects the function and performance of systems addressed by this Regulation and failures of energy supply available from the ISO 7638:2003 connector shall be indicated to the driver by the separate warning signal specified in point 2.2.1.29.2 of Annex I via pin 5 of the electrical connector conforming to ISO 7638:2003. In addition, towed vehicles equipped with an electric control line, when electrically connected to a tractor with an electric control line, shall provide the failure information for activation of the warning signal specified in point 2.2.1.29.2.1 of Annex I via the data communication part of the electric control line, when the prescribed service braking performance of the towed vehicle can no longer be ensured.

However, in the case of any failure of the energy supply available from the ISO 7638:2003 connector, the indication of the yellow warning signal via pin 5 of the electrical connector conforming to ISO 7638:2003 is sufficient under the condition that the full braking force is still available.

5. Additional requirements

5.1.   Tractors

5.1.1.   Generation of a braking signal to illuminate stop lamps

• 5.1.1.1. Activation of the service braking system by the driver shall generate a signal that will be used to illuminate the stop lamps.

• 5.1.1.2. Requirements for vehicles that utilise electronic signalling to control initial application of the service braking system and equipped with an endurance braking system:

Deceleration by the endurance braking system	Deceleration by the endurance braking system
≤ 1,3 m/sec2	> 1,3 m/sec2
May generate the signal	Shall generate the signal

• 5.1.1.3. In the case of vehicles equipped with a braking system of a specification different to that laid down in point 5.1.1.2, the operation of the endurance braking system may generate the signal irrespective of the deceleration produced.

• 5.1.1.4. The signal shall not be generated when deceleration is produced by the natural braking effect of the engine alone.

• 5.1.1.5. Activation of the service braking system by automatically commanded braking shall generate the signal mentioned above. However, when the deceleration generated is less than 0,7 m/s², the signal may be suppressed

At the time of type approval, compliance with this requirement shall be confirmed by the vehicle manufacturer.

• 5.1.1.6. Activation of part of the service braking system by selective braking shall not generate the signal mentioned above.

During a selective braking event, the function may change to automatically commanded braking.

• 5.1.1.7. In the case of vehicles equipped with an electric control line the signal shall be generated by the tractor when a message ‘illuminate stop lamps’ is received via the electric control line from the towed vehicle.

5.2.   Towed vehicles

• 5.2.1. Whenever power supplied by the ISO 7638:2003 connector is used for the functions referred to in point 2.1, the braking system shall have priority and be protected from an overload external to the braking system. This protection shall be a function of the braking system.

• 5.2.2. In the case of a failure in one of the control lines connecting two vehicles equipped according to point 2.1.4.1.2 of Annex I the towed vehicle shall use the control line not affected by the failure to ensure, automatically, the braking performance prescribed for the towed vehicle in point 3.2.1 of Annex II.

• 5.2.3. When the supply voltage to the towed vehicle falls below a value nominated by the manufacturer at which the prescribed service braking performance can no longer be guaranteed, the separate yellow warning signal specified in point 2.2.1.29.2 of Annex I shall be activated via pin 5 of the ISO 7638:2003 connector. In addition, towed vehicles equipped with an electrical control line, when electrically connected to a tractor with an electric control line, shall provide the failure information for actuation of the warning signal specified in point 2.2.1.29.2.1 of Annex I via the data communication part of the electric control line.

• 5.2.4. When the stored energy in any part of the service braking system of a towed vehicle equipped with an electric control line and electrically connected to a tractor with an electronic control line, falls to the value determined in accordance with point 5.2.4.1, a warning shall be provided to the driver of the tractor. The warning shall be provided by activation of the red signal specified in point 2.2.1.29.2.1 of Annex I and the towed vehicle shall provide the failure information via the data communication part of the electric control line. The separate yellow warning signal specified in point 2.2.1.29.2 of Annex I shall also be activated via pin 5 of the electrical connector conforming to ISO 7638:2003, to indicate to the driver that the low-energy situation is on the towed vehicle.

• 5.2.4.1. The low energy value referred to in point 5.2.4 shall be that at which, without re-charging of the energy reservoir and irrespective of the load condition of the towed vehicle, it is not possible to apply the service braking control device a fifth time after four full-stroke actuations and obtain at least 50 % of the prescribed performance of the service braking system of the relevant towed vehicle.

• 5.2.5. Activation of the service braking system

• 5.2.5.1. In the case of towed vehicles equipped with an electric control line the message ‘illuminate stop lamps’ shall be transmitted by the towed vehicle via the electric control line when the towed vehicle braking system is activated during ‘automatically commanded braking’ initiated by the towed vehicle. However, when the retardation generated is less than 0,7 m/s², the signal may be suppressed.

At the time of type approval, compliance with this requirement shall be confirmed by the vehicle manufacturer.

• 5.2.5.2. In the case of towed vehicles equipped with an electric control line the message ‘illuminate stop lamps’ shall not be transmitted by the towed vehicle via the electrical control line during selective braking initiated by the towed vehicle.

During a selective braking event, the function may change to automatically commanded braking.

6. Suppression of automatic braking

In the case of towed vehicles equipped with an electric control line and electrically connected to a tractor with an electric control line the automatic braking action specified in point 2.2.1.17.2.2 of Annex I may be suppressed as long as the pressure in the compressed air reservoirs of the towed vehicle is sufficient to ensure the braking performance specified in point 3.2.3 of Annex II.

Appendix 1

Compatibility between tractors and towed vehicles with respect to ISO 11992 data communications

1. General

• 1.1. The requirements of this Appendix shall only apply to tractors and towed vehicles equipped with an electric control line.

• 1.2. The ISO 7638 connector provides a power supply for the braking system or anti-lock braking system of the towed vehicle. In the case of vehicles equipped with an electric control line this connector also provides a data communication interface via Pins 6 and 7 as in point 2.1 of this Annex.

• 1.3. This Appendix lays down requirements applicable to the tractor and towed vehicle with respect to the support of messages defined within ISO 11992-2:2003 including Amd.1:2007.

• 1. The parameters defined within ISO 11992-2:2003 including Amd.1:2007 that are transmitted by the electric control line shall be supported as follows:

• 2.1. The following functions and associated messages are those specified within this Regulation that shall be supported by the tractor or towed vehicle as appropriate:
• 2.1.1. Messages transmitted from the tractor to the towed vehicle: Function/Parameter ISO 11992-2:2003 Reference Reference in this Regulation Service/secondary brake demand value EBS11 Byte 3-4 Appendix 1 to Annex II, point 3.1.3.2. Two electrical circuits brake demand value EBS12 Byte 3 Bit 1-2 Annex XII, point 3.1. Pneumatic control line EBS12 Byte 3 Bit 5-6 Annex XII, point 3.1.
• 2.1.2. Messages transmitted from the towed vehicle to the tractor: Function/Parameter ISO 11992-2:2003 Reference Reference in this Regulation Vehicle electrical supply sufficient/insufficient EBS22 Byte 2 Bit 1-2 Annex XII, point 5.2.3. Warning signal request EBS22 Byte 2 Bit 3-4 Annex XII, point 4.2.3., 5.2.4. and 5.2.3. Supply line braking request EBS22 Byte 4 Bit 3-4 Annex XII, point 4.2.2. Stop lamps request EBS22 Byte 4 Bit 5-6 Annex XII, point 5.2.5.1. Vehicle pneumatic supply sufficient/insufficient EBS23 Byte 1 Bit 7-8 Annex XII, point 5.2.4.

• 2.2. When the towed vehicle transmits the following message, the tractor shall provide a warning to the driver: Function/Parameter ISO 11992-2:2003 Reference Driver Warning Required Warning signal request EBS22 Byte 2 Bit 3-4 point 2.2.1.29.2.1 of Annex I

• 2.3. The following messages defined in ISO 11992-2:2003 including Amd.1:2007 shall be supported by the tractor or towed vehicle:
• 2.3.1. Messages transmitted from the tractor to the towed vehicle: No messages currently defined.
• 2.3.2. Messages transmitted from the towed vehicle to the tractor: Function/Parameter ISO 11992-2:2003 Reference Vehicle service brake active/passive EBS22 Byte 1, Bit 5-6 Braking via electric control line supported EBS22 Byte 4, Bit 7-8 Geometric data index EBS24 Byte 1 Geometric data index content EBS24 Byte 2

• 2.4. The following messages shall be supported by the tractor or towed vehicle as appropriate when the vehicle is installed with a function associated with that parameter:
• 2.4.1. Messages transmitted from the tractor to the towed vehicle: Function/Parameter ISO 11992-2:2003 Reference Vehicle type EBS11 Byte 2, Bit 3-4 VDC (Vehicle Dynamic Control) Active/passive EBS11 Byte 2, Bit 5-6 Brake demand value for front or left side of vehicle EBS11 Byte 7 Brake demand value for rear or right side of vehicle EBS11 Byte 8 ROP (Roll Over Protection) system enabled/disabled EBS12 Byte 1, Bit 3-4 YC (Yaw Control) system enabled/disabled EBS12 Byte 1, Bit 5-6 Enable/disable towed vehicle ROP (Roll Over Protection) system EBS12 Byte 2, Bit 1-2 Enable/disable towed vehicle YC (Yaw Control) system EBS12 Byte 2, Bit 3-4 Traction help request RGE11 Byte 1, Bit 7-8 Lift axle 1 — position request RGE11 Byte 2, Bit 1-2 Lift axle 2 — position request RGE11 Byte 2, Bit 3-4 Steering axle locking request RGE11 Byte 2, Bit 5-6 Seconds TD11 Byte 1 Minutes TD11 Byte 2 Hours TD11 Byte 3 Months TD11 Byte 4 Day TD11 Byte 5 Year TD11 Byte 6 Local minute offset TD11 Byte 7 Local hour offset TD11 Byte 8
• 2.4.2. Messages transmitted from the towed vehicle to the tractor: Function/Parameter ISO 11992-2:2003 Reference Support of side or axle wise brake force distribution EBS21 Byte 2, Bit 3-4 Wheel based vehicle speed EBS21 Byte 3-4 Lateral acceleration EBS21 Byte 8 Vehicle ABS active/passive EBS22 Byte 1, Bit 1-2 Amber warning signal request EBS22 Byte 2, Bit 5-6 Vehicle type EBS22 Byte 3, Bit 5-6 Loading ramp approach assistance EBS22 Byte 4, Bit 1-2 Axle load sum EBS22 Byte 5-6 Tyre pressure sufficient/insufficient EBS23 Byte 1, Bit 1-2 Brake lining sufficient/insufficient EBS23 Byte 1, Bit 3-4 Brake temperature status EBS23 Byte 1, Bit 5-6 Tyre/wheel identification (pressure) EBS23 Byte 2 Tyre/wheel identification (lining) EBS23 Byte 3 Tyre/wheel identification (temperature) EBS23 Byte 4 Tyre pressure (actual tyre pressure) EBS23 Byte 5 Brake lining EBS23 Byte 6 Brake temperature EBS23 Byte 7 Brake cylinder pressure first axle left wheel EBS25 Byte 1 Brake cylinder pressure first axle right wheel EBS25 Byte 2 Brake cylinder pressure second axle left wheel EBS25 Byte 3 Brake cylinder pressure second axle right wheel EBS25 Byte 4 Brake cylinder pressure third axle left wheel EBS25 Byte 5 Brake cylinder pressure third axle right wheel EBS25 Byte 6 ROP (Roll Over Protection) system enabled/disabled EBS25 Byte 7, Bit 1-2 YC (Yaw Control) system enabled/disabled EBS25 Byte 7, Bit 3-4 Traction help RGE21 Byte 1, Bit 5-6 Lift axle 1 position RGE21 Byte 2, Bit 1-2 Lift axle 2 position RGE21 Byte 2, Bit 3-4 Steering axle locking RGE21 Byte 2, Bit 5-6 Tyre wheel identification RGE23 Byte 1 Tyre temperature RGE23 Byte 2-3 Air leakage detection (Tyre) RGE23 Byte 4-5 Tyre pressure threshold detection RGE23 Byte 6, Bit 1-3

• 2.5. The support of all other messages defined within ISO 11992-2:2003 including Amd.1:2007 is optional for the tractor and towed vehicle.

Appendix 2

Test procedure to assess the functional compatibility of vehicles equipped with electric control lines

1. General

• 1.1. This Appendix lays down a procedure that may be used by the Technical Service to check tractors and towed vehicles equipped with an electric control line against the functional and performance requirements referred to in point 2.2. of Annex XII.

• 1.2. The references to ISO 7638 within this Appendix apply to ISO 7638-1:2003 for 24V applications and ISO 7638-2:2003 for 12V applications.

2. Tractors

2.1.   ISO 11992 towed vehicle simulator

The simulator shall:

• 2.1.1. Have a connector meeting ISO 7638:2003 (7 pin) to connect to the vehicle under test. Pins 6 and 7 of the connector shall be used to transmit and receive messages complying with ISO 11992:2003 including ISO 11992-2:2003 and its Amd.1:2007;

• 2.1.2. Be capable of receiving all of the messages transmitted by the motor vehicle to be type approved and be capable of transmitting all towed vehicle messages defined within ISO 11992-2:2003 and its Amd.1:2007;

• 2.1.3. Provide a direct or indirect readout of messages, with the parameters in the data field shown in the correct order relative to time; and

• 2.1.4. Include a facility to measure coupling head response time in accordance with point 2.6 of Annex III.

2.2.   Checking procedure

• 2.2.1. Confirm that the manufacturer's/supplier's information document demonstrates compliance with the provisions of ISO 11992 with respect to the physical layer, data link layer and application layer.

• 2.2.2. Check the following, with the simulator connected to the motor vehicle via the ISO 7638 interface and whilst all towed vehicle messages relevant to the interface are being transmitted:

• 2.2.2.1. Control line signalling:

• 2.2.2.1.1. The parameters defined in EBS 12 byte 3 of ISO 11992-2:2003 and its Amd.1:2007 shall be checked against the specification of the vehicle as follows: Control Line Signalling EBS 12 Byte 3 Bits 1-2 Bits 5-6 Service braking demand generated from one electrical circuit 00b Service braking demand generated from two electrical circuits 01b Vehicle is not equipped with a pneumatic control line [^E0007]

00b Vehicle is equipped with a pneumatic control line

01b (¹) This specification of vehicle is prohibited following point 2.1.4.1.3 of Annex I.

• 2.2.2.2. Service/Secondary brake demand:

• 2.2.2.2.1 The parameters defined in EBS 11 of ISO 11992-2:2003 and its Amd.1:2007 shall be checked as follows: Test condition Byte reference Electrical control line signal value Service brake pedal and secondary brake control released 3 - 4 0 Service brake pedal fully applied 3 - 4 33280d to 43520d (650 to 850 kPa) Secondary brake fully applied [^E0008] 3 - 4 33280d to 43520d (650 to 850 kPa) (¹) Optional on tractors with electric and pneumatic control lines when the pneumatic control line fulfils the relevant requirements for secondary braking.

• 2.2.2.3. Failure warning:

• 2.2.2.3.1. Simulate a permanent failure in the communication line to pin 6 of the ISO 7638 connector and check that the yellow warning signal specified in point 2.2.1.29.1.2 of Annex I is displayed.

• 2.2.2.3.2. Simulate a permanent failure in the communication line to pin 7 of the ISO 7638 connector and check that the yellow warning signal specified in point 2.2.1.29.1.2 of Annex I is displayed.

• 2.2.2.3.3. Simulate message EBS 22, byte 2 with bits 3 - 4 set to 01b and check that the warning signal specified in point 2.2.1.29.1.1 of Annex I is displayed.

• 2.2.2.4. Supply line braking request:

For power-driven vehicles which can be operated with towed vehicles connected via an electric control line only:

Only the electric control line shall be connected.

Simulate message EBS 22, byte 4 with bits 3 - 4 set to 01b and check that when the service brake, secondary brake or parking braking system is fully actuated the pressure in the supply line falls to 150 kPa within the following two seconds.

Simulate a continuous absence of data communication and check that when the service brake, secondary brake or parking braking system is fully actuated the pressure in the supply line falls to 150 kPa within the following two seconds.

• 2.2.2.5. Response time:

• 2.2.2.5.1. Check that, with no faults present, the control line response requirements laid down in point 2.6. of Annex III are met.

• 2.2.2.6. Illumination of stop lamps

Simulate message EBS 22 byte 4 bits 5 to 6 set to 00 and check that the stop lamps are not illuminated.

Simulate message EBS 22 byte 4 bits 5 to 6 set to 01 and check that the stop lamps are illuminated.

• 2.2.3. Additional checks

- 2.2.3.1. At the discretion of the Technical Service the checking procedures laid down in points 2.2.1 and 2.2.2 may be repeated with the non-braking functions relevant to the interface in different states or switched off.

- 2.2.3.2. Point 2.4.1. of Appendix 1 defines additional messages that shall under specific circumstances be supported by the tractor. Additional checks may be carried out to verify the status of supported messages to ensure the requirements of point 2.3 are fulfilled.

3.1.   ISO 11992 tractor simulator

The simulator shall:

• 3.1.1. Have a connector meeting ISO 7638:2003 (7 pin) to connect to the vehicle under test. Pins 6 and 7 of the connector shall be used to transmit and receive messages complying with ISO 11992:2003 including ISO 11992-2:2003 and its Amd.1:2007;

• 3.1.2. Have a failure warning display and an electrical power supply for the towed vehicle;

• 3.1.3. Shall be capable of receiving all of the messages transmitted by the towed vehicle to be type approved and be capable of transmitting all motor vehicle messages defined within ISO 11992-2:2003 and its Amd.1:2007.

- 3.1.4. Provide a direct or indirect readout of messages with the parameters in the data field shown in the correct order relative to time; and

• 3.1.5. Include a facility to measure brake system response time in accordance with point 4.5.2 of Annex III.

3.2.   Checking procedure

• 3.2.1. Confirm that the manufacturer's or supplier's Information Document, demonstrates compliance with the provisions of ISO 11992:2003 including ISO 11992-2:2003 and its Amd.1:2007 with respect to the physical layer, data link layer and application layer.

• 3.2.2. Check the following, with the simulator connected to the towed vehicle via the ISO 7638 interface and whilst all tractor messages relevant to the interface are being transmitted:

• 3.2.2.1. Service brake system function:

• 3.2.2.1.1. The towed vehicle response to the parameters defined in EBS 11 of ISO 11992-2:2003 and its Amd.1:2007 shall be checked as follows:

The pressure in the supply line at the start of each test shall be ≥ 700 kPa and the vehicle shall be laden (the loading condition may be simulated for the purpose of this check).

• 3.2.2.1.1.1. For towed vehicles equipped with pneumatic and electric control lines:

Both control lines shall be connected;

Both control lines shall be signalled simultaneously;

The simulator shall transmit message byte 3, bits 5-6;

Of EBS 12 set to 01b to indicate to the towed vehicle that a pneumatic control line should be connected.

Parameters to be checked:

Message transmitted by the simulator	Message transmitted by the simulator	Pressure at the brake chambers
Byte reference	Digital demand value	Pressure at the brake chambers
3-4	0	0 kPa
3-4	33280d (650 kPa)	As defined in the vehicle manufacturer's brake calculation

• 3.2.2.1.1.2. Towed vehicles equipped with pneumatic and electric control lines or an electric control line only:

Only the electric control line shall be connected

The simulator shall transmit the following messages:

Byte 3, bits 5-6 of EBS 12 set to 00b to indicate to the towed vehicle that a pneumatic control line is not available, and byte 3, bits 1-2 of EBS 12 set to 01b to indicate to the towed vehicle that the electric control line signal is generated from two electric circuits.

Parameters to be checked:

Message transmitted by the simulator	Message transmitted by the simulator	Pressure at the brake chambers
Byte reference	Digital demand value	Pressure at the brake chambers
3-4	0	0 kPa
3-4	33280d (650 kPa)	As defined in the vehicle manufacturer's brake calculation

• 3.2.2.1.2. For towed vehicles equipped with only an electric control line, the response to messages defined in EBS 12 of ISO 11992-2:2003 and its Amd.1:2007 shall be checked as follows:

The pneumatic supply line at the start of each test shall be ≥ 700 kPa.

The electric control line shall be connected to the simulator.

The simulator shall transmit the following messages:

Byte 3, bits 5-6 of EBS 12 set to 01b to indicate to the towed vehicle that a pneumatic control line is available.

Byte 3-4 of EBS 11 shall be set to 0 (no service brake demand)

The response to the following messages shall be checked:

EBS 12, Byte 3, Bit 1-2	Pressure in the brake chambers or reaction of the towed vehicle
01b	0 kPa (service brake released)
00b	The towed vehicle is automatically braked to demonstrate that the combination is not compatible. A signal should also be transmitted via Pin 5 of the ISO 7638:2003 connector (yellow warning).

• 3.2.2.1.3. For towed vehicles connected with only an electrical control line, the response of the towed vehicle to a failure in the electric control transmission of the towed vehicle which results in a reduction in braking performance to at least 30 % of the prescribed value shall be checked by the following procedure:

The pneumatic supply line at the start of each test shall be ≥ 700 kPa.

The electric control line shall be connected to the simulator.

Byte 3, bits 5-6 of EBS 12 set to 00b to indicate to the towed vehicle that a pneumatic control line is not available.

Byte 3, bits 1-2 of EBS 12 set to 01b to indicate to the towed vehicle that the electric control line signal is generated from two independent circuits.

The following shall be checked:

Test condition	Braking system response
With no faults present in the towed vehicle braking system	Check that the braking system is communicating with the simulator and that Byte 4, bits 3-4 of EBS 22 is set to 00b.
Introduce a failure in the electric control transmission of the towed vehicle braking system that prevents at least 30 per cent of the prescribed braking performance from being maintained	Check that Byte 4, bits 3-4 of EBS 22 is set to 01b or The data communications to the simulator has been terminated

• 3.2.2.2. Failure warning

• 3.2.2.2.1. Check that the appropriate warning message or signal is transmitted under the following conditions:

• 3.2.2.2.1.1. Where a permanent failure within the electric control transmission of the towed vehicle braking system precludes the service braking performance being met, simulate such a failure and check that byte 2, bits 3-4 of EBS 22 transmitted by the towed vehicle is set to 01b. A signal should also be transmitted via pin 5 of the ISO 7638 connector (yellow warning).

• 3.2.2.2.1.2. Reduce the voltage on pins 1 and 2 of the ISO 7638 connector to below a value nominated by the manufacturer which precludes the service braking system performance from being fulfilled and check that byte 2, bits 3-4 of EBS 22 transmitted by the towed vehicle are set to 01b. A signal should also be transmitted via pin 5 of the ISO 7638 connector (yellow warning).

• 3.2.2.2.1.3. Check compliance with the provisions of point 5.2.4 of this Annex by isolating the supply line. Reduce the pressure in the towed vehicle pressure storage system to the value nominated by the manufacturer. Check that byte 2, bits 3-4 of EBS 22 transmitted by the towed vehicle is set to 01b and that byte 1, bits 7-8 of EBS 23 is set to 00. A signal should also be transmitted via pin 5 of the ISO 7638 connector (yellow warning).

• 3.2.2.2.1.4. When the electrical part of the braking equipment is first energised check that byte 2, bits 3-4 of EBS 22 transmitted by the towed vehicle is set to 01b. After the braking system has checked that no defects that require identification by the red warning signal are present the message referred to in this point shall be set to 00b.

• 3.2.2.3. Response time checking

• 3.2.2.3.1. Check that, with no faults present, the braking system response time requirements laid down in point 4.5.2 of Annex III are met.

• 3.2.2.4. Automatically commanded braking

In case the towed vehicle includes a function where its operation results in an automatically commanded braking intervention, the following shall be checked:

If no automatically commanded braking intervention is generated, check that message EBS 22 byte 4 bits 5 to 6 are set to 00.

Simulate an automatically commanded braking intervention, when the resulting deceleration is ≥ 0,7 m/sec², check that message EBS 22 byte 4 bits 5 to 6 are set to 01.

• 3.2.2.5. Vehicle stability function

In the case of a towed vehicle equipped with a vehicle stability function, the following checks shall be carried out:

When the vehicle stability function is inactive, check that message EBS 21 byte 2 bits 1 to 2 are set to 00.

• 3.2.2.6. Support of the electric control line

Where the towed vehicle braking system does not support braking via the electric control line check that message EBS 22 byte 4 bits 7 to 8 are set to 00.

Where the towed vehicle braking system supports the electric control line, check that message EBS 22 byte 4 bits 7 to 8 are set to 01.

• 3.2.3. Additional checks

• 3.2.3.1. At the discretion of the Technical Service the checking procedures laid down in points 3.2.1 and 3.2.2 may be repeated with the non-braking messages relevant to the interface in different states or switched off.

Where repeat measurements of the brake system response time are carried out, variations in the value recorded may occur due to the reaction of the vehicle pneumatics. In all cases the prescribed response time requirements shall be met.

- 3.2.3.2. Point 2.4.2 of Appendix 1 defines additional messages that shall under specific circumstances be supported by the towed vehicle. Additional checks may be carried out to verify the status of supported messages to ensure the requirements of point 2.3 of this Annex are fulfilled.

ANNEX XIII

Requirements applying to hydraulic braking systems capable of hydraulic connections of the single-line type

- 1.1. The hydraulic control line of the tractor referred to in point 2.1.5.1.1. of Annex I may operate as a hydraulic connection of the single-line type provided that the pressures generated on the connector comply with points 1.1.1, 1.1.2 and 1.1.3.

• 1.3. The service braking system of the tractor shall be fitted with a device so designed that if the towed vehicle braking system should fail, or the control line between the tractor and towed vehicle should break, it will still be possible to brake the tractor with the effectiveness prescribed for the secondary braking system in this Regulation.

• 2.1. Type of connection: hydraulic control line with the male connector on the tractor and the female connector on the towed vehicle. The connectors shall comply with ISO 5676:1983.

• 2.2. With the engine running and the control device of the service braking system of the tractor fully applied a pressure between 10 000 kPa and 15 000 kPa shall be generated on the control line.

• 2.3. With the engine running and no brake control device on the tractor applied (driving or stand-by condition), the pressure supplied at the coupling head of the control line shall be 0⁺²⁰⁰ kPa.

- 2.4. The response time requirements of Annex III do not apply to this type of connection.

• 2.5. The compatibility requirements according to Appendix 1 to Annex II do not apply to this type of connection.

As an alternative to the requirements of sections 1 and 2, hydraulic connection of the single line type installed on tractors shall fulfil all the requirements of this section, in addition to the provisions of point 2.1.

• 3.1. The hydraulic circuit shall be provided with a relief valve to prevent hydraulic pressures exceeding 15 000 kPa.

• 3.2. With no brake control device (including parking brake) applied on the tractor, at any engine revolutions per minute (RPM) between low idle and rated speed, pressure at coupling head shall be between 1 000 and 1 500 kPa.

• 3.3. Applying tractor service brakes gradually, pressure at coupling head shall increase progressively and reach the maximum specified value, which shall be between 12 000 and 14 000 kPa. Requirement shall be fulfilled at any engine RPM, as described in point 3.2.

• 3.4. Permissible relationship between braking rate TM/FM and the coupling head pressure pm shall be lower than line AAA of Figure 1. Requirement shall be fulfilled by the unladen vehicle.

• 3.5. The response time at the coupling head, measured connecting the towed vehicle simulator (as described in point 3.10) to the tractor, shall not be higher than 0,6 seconds. The response time shall be measured at the coupling head, starting from the moment of the pedal actuation until the moment when pressure reaches the value of 7 500 kPa. During the test, engine RPM shall be set to 2/3 of the rated speed. The ambient and vehicle temperature shall be stabilised between 10 °C and 30 °C. The pedal actuation time necessary to reach a pressure of 10 000 kPa at the coupling head, shall be not less than 0,2 seconds.

• 3.6. In case of failure of the towed vehicle braking system part, located on the tractor side, a pressure drop to 0 kPa (measured at the coupling head) shall be generated within 1 second, in order to apply the brakes of the towed vehicle. The same provision applies in case of shut off or low efficiency of the energy source.

• 3.7. In case of failure of the tractor service brakes, operator shall be able to drop the pressure at the coupling head to 0 kPa. This requirement may be achieved by an auxiliary manual control device.

• 3.8. The tractor shall be equipped with the warning signal specified in point 2.2.1.29.1.1 of Annex I; it shall be activated when the pressure in the towed vehicle braking system drops below 1 000 ^{(+0 – 200)} kPa.

• 3.9. Braking valve and energy source shall be marked in accordance with the requirements laid down in Article 24 of Delegated Regulation (EU) 2015/208.

• 3.10. Towed vehicle simulator: The device simulating the towed vehicle braking system shall include a hydraulic circuit provided with one female coupler as per ISO 5676-1983 and two identical hydraulic energy storage devices, fitted with spring elements and fulfilling the requirements reported in Figure 2. The simulator shall be manufactured according to the provisions of Figure 3.

Figure 1

Relationship between braking rate TM/FM and coupling head pressure pm

Image omitted; see official source

pm	=	stabilised hydraulic pressure at the coupling head (kPa).
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TM	=	sum of braking forces at the periphery of all wheels of tractors
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FM	=	total normal static reaction of road surface on wheels of tractors

Figure 2

Characteristic of the towed vehicle simulator, depending on its maximum permissible mass

Image omitted; see official source

• — diagram A B C for maximum permissible mass up to 14 tons.

• — diagram A D E for maximum permissible mass higher than 14 tons

Note: tolerance admitted ± 2 %

Figure 3

Towed vehicle simulator layout

Image omitted; see official source

1	=	hose of 2 000 mm length with one female coupler as per ISO 5676-1983;
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2	=	tube of internal diameter 8 mm and length of 4 000 mm;
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3	=	tube of internal diameter 8 mm and length of 1 000 mm;
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4	=	tube of internal diameter 8 mm and length of 1 000 mm;
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5	=	piston brake simulating elements;
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6	=	spring adjusted elements acting on the total stroke of the piston;
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7	=	spring adjusted elements acting only at the end of the pistons stroke.

[^E0001]: Commission Delegated Regulation (EU) 2015/208 of 8 December 2014 supplementing Regulation (EU) No 167/2013 of the European Parliament and of the Council with regard to vehicle functional safety requirements for the approval of agricultural and forestry vehicles (OJ L 42, 17.2.2015, p. 1).

[^E0002]: Commission Implementing Regulation (EU) 2015/504 of 11 March 2015 implementing Regulation (EU) No 167/2013 of the European Parliament and of the Council with regard to the administrative requirements for the approval and market surveillance of agricultural and forestry vehicles (OJ L 85, 28.3.2015, p. 1.).

[^E0005]: Points 2.3.10, 2.3.11 and 2.3.12 only apply to the parking braking system differential travel calculation method.