Pinpoint Test L: The Engine Only Traction Control (EOTC) System Is Inoperative
Anti-Lock Control
Pinpoint Tests
Pinpoint Test L: The Engine Only Traction Control (EOTC) System is Inoperative
Refer to Wiring Diagram Set 42, Vehicle Dynamic Systems for schematic and connector information. Diagrams By Number
Normal Operation
The Engine Only Traction Control (EOTC) is controlled by the PCM, the PCM utilizes the ABS module for wheel speed information only. When the PCM detects a wheel spinning excessively, it will assist with traction control by adjusting engine timing and decreasing fuel injector pulses.
The EOTC system can be disabled by pressing the stability/traction control switch located in the instrument panel. The switch is hardwired to the PCM. Fused ignition voltage is sent to the stability/traction control switch along circuit 640 (RD/YE) from Central Junction Box (CJB) fuse 26 (10A). When the switch is pressed, this voltage is sent to the PCM along circuit 959 (GY). When the PCM receives this voltage it will disable the EOTC system and send a message to the Instrument Cluster (IC) and the Lighting Control Module (LCM) along the High Speed Controller Area Network (HS-CAN) bus.
If wheel speed sensor DTCs are present in the ABS module or communication DTCs are present in the IC, PCM or ABS module, the EOTC system will also be disabled. When the system is disabled due to DTCs being present, both the ABS warning indicator and the stability/traction control indicator will be illuminated.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Stability/traction control switch
- PCM
- IC
- ABS module
PINPOINT TEST L: THE ENGINE ONLY TRACTION CONTROL (EOTC) SYSTEM IS INOPERATIVE
NOTICE: The Flex Probe Kit must be used for all test connections. Use of standard multi-meter probes may damage wiring terminals.
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L1 VERIFY THAT THE SYSTEM CAN BE ENABLED/DISABLED BY THE STABILITY/TRACTION CONTROL SWITCH
- Test drive the vehicle, press the stability/traction control switch and verify that the EOTC system can be enabled/disabled by the switch.
- Can the EOTC system be enabled/disabled by the switch?
Yes
EXPLAIN correct system operation to the customer.
No
GO to L2.
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L2 CHECK FOR ABS MODULE, PCM AND IC DTCs
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - All Continuous Memory Diagnostic Trouble Codes (CMDTCs).
- Are any DTCs present in the PCM, IC or ABS module?
Yes
For PCM DTCs, REFER to Computers and Control Systems Information.
For IC DTCs, REFER to the DTC Chart in Body Control Systems. Diagnostic Trouble Code (DTC) Chart
For ABS module DTCs, GO to the ABS Module DTC Chart. [1][2]Diagnostic Trouble Code Descriptions
No
GO to L3.
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L3 VERIFY THAT THE PCM IS CONFIGURED FOR EOTC
- Configure the PCM, refer to Programmable Module Installation (PMI) in Information Bus. Programming and Relearning
- Test drive the vehicle and verify that the EOTC system operates correctly.
- Does the EOTC system operate correctly?
Yes
Return the vehicle to the customer, the concern was due to improper or incomplete PCM configuration.
No
GO to L4.
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L4 CHECK THE SWITCH CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between stability/traction control switch C280-1, circuit 959 (GY), harness side and ground.
- Is any voltage present?
Yes
REPAIR circuit 959 (GY). TEST the system for normal operation.
No
INSTALL a new stability/traction control switch. REFER to Stability/Traction Control Switch Service and Repair. TEST the system for normal operation.
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