RangeRovers.net Forum banner

1 - 4 of 4 Posts

·
Registered
2002-2005 Range Rover MkIII / L322
Joined
·
9 Posts
Discussion Starter #1
I have had issues with my '03 Range Rovers with the BMW 4.4 liter engine: started with the infamous "three amigos," and a repair shop did the part replacement process last year until I now have the three amigos, plus several more problems believed to be electrical (speedometer does not work. Right rear turn signal does not work. Transmission in fail safe mode. Etc.).
To drive it I want to simply disable the ABS, but do not want to do it by disconnecting the multi-point connector at the ABS unit. Looking for the relay to disable the ABS. Please provide the diagram (picture) with the specific relay circled.
Thanks in advance.
 

·
Registered
2006-2009 Range Rover MkIII / L322
Joined
·
1,145 Posts
You really can't just deenergize the ABS without totally screwing up just about every other system in the truck, and there is no single relay you can pull to do it, its pretty well integrated into all of the suspension and driveline systems. Speedometer not working is a classic sign on a bad wheel speed sensor, wire or possibly in your case a bad ABS ECU.

ANTI-LOCK BRAKING SYSTEM (ABS)
DESCRIPTION
General
New Range Rover is equipped with Dynamic Stability Control (DSC) for enhanced braking
and stability control. Functions of the DSC include:

Hill Decent Control (HDC).
Electronic traction control (ETC).
Anti-lock Braking System (ABS).

The DSC system for New Range Rover provides all of the following functions and features:

Optimised traction under all driving conditions.
Optimised directional control (Longitudinal Stability).
Lateral stability (Correction for over steer/under steer).
Corner Braking Control (CBC).
Emergency Brake Assist (EBA).
Electronic Brake Force Distribution (EBD).

For a detailed description of the ABS, HDC, and ETC systems, refer to the Brakes section
of the System Description and Operation Workshop Manual.

OPERATION

Power Distribution

Feed from the positive battery terminal (C0192) is supplied to the following on R wires:
Fusible link 2 (C0632) – V8 vehicles only.
Maxi fuse 63 (C0632).
Fuse 13 (C0632).
Fuse 53 (C0632).
Fuse 55 (C0632).
Fuse holder (C1875) – Td6 vehicles only.

Maxi fuse 63 (C0580) and fuse 55 (C0583) provide constant battery feeds to the ABS ECU (C0506) on R and RB wires respectively. The ABS ECU is earthed on a pair of N wires. Fuse 13 (0586) provides a constant battery feed to the steering angle sensor (C0862) on an RG wire.
Fuse 53 (C0583) provides a constant battery feed to the ignition switch (C0099 on Td6 vehicles, C0028 on V8 vehicles) on an R wire. When the ignition switch is turned to the 'auxiliary' position, current flows across the switch (C0099 on Td6 vehicles, C0028 on V8 vehicles) to fuse 37 of the passenger compartment fuse box (C0585) on a PB wire.

Fuse 37 (C0587) provides an auxiliary ignition feed to the Dynamic Stability Control (DSC) switch (C0700), located on the centre console, on a GBY wire.

V8

Fusible link 2 (C0632) provides a constant battery feed to the ECM relay (C1895) on an R wire. Operation of the ECM relay (C1895) is controlled by the ECM (C0604) on an N wire. The energised ECM relay (C1895) provides a feed to fuse 51 of the passenger compartment fuse box (C0584) on an RW wire. Fuse 51 (C0584) is connected to the ABS ECU (C0506) and the steering angle sensor (C0862) by a pair of RW wires.


Td6


The 100A fuse within the fuse holder (C1878) provides a constant battery feed to the ECM relay (C1895) on an R wire. Operation of the ECM relay (C1895) is controlled by the ECM (C0604) on an N wire. The energised ECM relay (C1895) provides a feed to fuse 51 of the passenger compartment fuse box (C0584) on an RW wire. Fuse 51 (C0584) is connected to the ABS ECU (C0506) and the steering angle sensor (C0862) by a pair of RW wires.

ABS


Wheel Speed Sensors

The ABS ECU (C0506) provides a feed to all four wheel speed sensors as follows:
To the LH front wheel speed sensor (C0516) on an R wire.
To the RH front wheel speed sensor (C0517) on a Y wire.
The LH rear wheel speed sensor (C0502) on a W wire.
To the RH rear wheel speed sensor (C0503) on a G wire.

The wheel speed sensors are hall effect sensors, and provide the ABS ECU with a square wave form signal. This signal rises and falls between approximately 2.5V and 0.75V. By measuring the frequency of the waveform, the ABS ECU can calculate the speed of the road wheel. The sensors provide the ABS ECU (C0506) with a wheel speed signal as follows:

From the LH front wheel speed sensor (C0516) on a UR wire.
From the RH front wheel speed sensor (C0517) on a UY wire.
From the LH rear wheel speed sensor (C0502) on a UW wire.
From the RH rear wheel speed sensor (C0503) on a UG wire.

DSC

DSC Switch
DSC is active as soon as the ignition switch is turned to the 'ignition' position. DSC can be switched off by pressing the non-latching master switch located on the centre console.
When the ABS ECU (C0506) receives a momentary feed from the DSC switch (C0700) on a BY wire, it suspends DSC operation. Pressing the switch a second time reinstates DSC.

Steering Angle Sensor
The steering angle sensor (C0862) receives a constant battery feed from fuse 13 of the passenger compartment fuse box (C0586) on an RG wire, and a feed from the energised ECM relay (C1895) via fuse 51 of the passenger compartment fuse box (C0584) on an RW wire. The sensor (C0862) is earthed on an NB wire. The steering angle sensor (C0862) transmits steering angle and rate of steering messages via the Can bus on YN (low) and YB (high) wires. These signals are created by two potentiometers located within the sensor. The ABS ECU uses these messages to enable the DSC system control lateral stability.


Brake Fluid Level Warning Switch

If the brake fluid level is below the minimum level, DSC operation is suspended. The ABS ECU (C0506) monitors the condition of the brake fluid level switch (C0026) via an NGY wire.


HDC

The HDC switch (C0365) is mounted on the side of the gear selector lever, and is provided an auxiliary ignition feed from fuse 35 of the passenger compartment fuse box (C0587) on a GBY wire. The ABS ECU (C0506) monitors the condition of the HDC switch (C0365) via a BG wire.

EBA

Brake Pedal Switch
The brake pedal switch (C0075) is provided an auxiliary ignition feed from fuse 9 of the passenger compartment fuse box (C0587) on a PY wire. The ABS ECU (C0506) monitors the condition of the brake pedal switch (C0075) on a UR wire to enable it to operate its Emergency Brake Assist (EBA) function.
 

·
Registered
2006-2009 Range Rover MkIII / L322
Joined
·
1,145 Posts
I stole it from the electrical supplement, not even I could write that up on my own.
 
1 - 4 of 4 Posts
Top