**stop press**there is another module? GEM generic electronic module. Behind dash left side of steering column. The data lines from this module only go to the turn signals at the rear? And front park/turn signals? Have you got a feed to the the light that is out? I think it is likely you have a break in the brown live wire to the lamps both lives go to a connector behind left kick panel. I don't think it is anything to do with a control module. Simply a break in the live wire to the light that is out. Try wiring a live from a light that is working to it?
I have checked the wiring diagram for the ABS/TC module and cannot find any output wires to the rear lights?
DESCRIPTION & OPERATION
Vehicle has 2 module communications networks. The Powertrain Control Module (PCM) and Anti-Lock Brake System/Traction Control (ABS/TC) module (if equipped with traction control) are connected to the multiplex communications network through a pair of twisted wires or BUS. The BUS network is also referred to as Standard Corporate Protocol (SCP). The BUS consists of (+) circuit No. 914 and a (-) circuit No. 915. The air bag diagnostic monitor and all other optional modules, the Generic Electronic Module (GEM) and Anti-Lock Brake System (ABS) control module (on models not equipped with traction control), are connected to the ISO 9141 diagnostic communications network through a single wire (circuit No. 70). Both networks are connected to the Data Link Connector (DLC). This article is used to diagnose BUS and ISO communications network circuit faults. For module locations, see COMPONENT LOCATIONS table.
The 4-wheel Anti-Lock Brake System (ABS) is designed to allow the vehicle to stop in the shortest possible distance while maintaining improved steering control under most conditions. Some models are equipped with traction control, which is integral with the anti-lock brake system.
ABS system consists of an Anti-Lock Brake Control Module (ABCM), Hydraulic Control Unit (HCU), 4 wheel speed sensors and toothed sensor rings, brake light relay, ABS and BRAKE warning lights, fluid level switch, brake on/off switch, and traction control switch. The ABCM and HCU are packaged in one unit identified as Electronic Hydraulic Control Unit (EHCU). The traction control valve block is 6" (152 mm) long, has 4 outlet ports and uses M12 (6 mm) tub nuts on tubes going to master cylinder.
NOTE:For more information on brake system, see appropriate DISC & DRUM article.
When brakes are applied, fluid under pressure is transmitted through 4 normally open solenoid valves located inside Hydraulic Control Unit (HCU) to wheels. If Anti-Lock Brake Control Module (ABCM) senses a wheel is about to lock, based on input from wheel speed sensor, normally open solenoid valve is energized closed (pulsated) for affected wheel. This prevents fluid from entering brake circuit for affected wheel. The ABCM looks at sensor signal from affected wheel. If affected wheel is still decelerating, ABCM opens solenoid valve (pulsates), returning fluid back to HCU. When affected wheel comes back up to speed, ABCM returns solenoid valve to normal open condition, allowing fluid to affected wheel.
The ABCM monitors electromechanical components of brake system. A malfunction of Anti-Lock Brake System (ABS) will cause ABCM to inhibit system operation. ABS warning light will be illuminated on instrument panel. Normal power assisted braking will remain operational.
When ignition is placed in RUN position, ABCM will perform a self-check on ABS electrical system by illuminating ABS warning light for 2-3 seconds. When vehicle speed reaches 4 MPH, valves and motor will be briefly powered to ensure operation. During vehicle operation, ABCM monitors all electrical ABS functions and some hydraulic operations.
Malfunction of anti-lock brake system will cause anti-lock brake module to shut off or inhibit the system. Loss of hydraulic fluid in brake master cylinder reservoir will disable anti-lock system.
Anti-Lock Control Module (ABCM) & Hydraulic Control Module (HCU)
ABCM is located under battery tray in left front corner of engine compartment.
Tuesday, November 18th, 2008 AT 8:25 PM