Pinpoint Test I: The Engine Only Traction Control (EOTC) System Cannot be Disabled
Anti-Lock Control
Pinpoint Tests
Pinpoint Test I: The Engine Only Traction Control (EOTC) System Cannot be Disabled
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) system is controlled by the PCM and utilizes the ABS module for wheel speed information only. EOTC helps maintain vehicle traction during acceleration by modulating engine torque. The EOTC system can be disabled by pressing the stability/traction control switch located in the instrument panel. 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.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Stability/traction control switch
- PCM
PINPOINT TEST I: THE ENGINE ONLY TRACTION CONTROL (EOTC) SYSTEM CANNOT BE DISABLED
NOTICE: The Flex Probe Kit must be used for all test connections. Use of standard multi-meter probes may damage wiring terminals.
-------------------------------------------------
I1 CHECK FOR 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, Instrument Cluster (IC) or ABS module?
Yes
For PCM DTCs, REFER to Computers and Control Systems.
For IC DTCs, REFER to the DTC Chart in Multifunction Electronic Modules Testing and Inspection.
For ABS module DTCs, GO to the ABS Module DTC Chart. Diagnostic Trouble Code Tests and Associated Procedures
No
GO to I2.
-------------------------------------------------
I2 CHECK THE STABILITY/TRACTION CONTROL SWITCH
- Ignition OFF.
- Disconnect: Stability/Traction Control Switch C280.
- Place the stability/traction control switch in the ON position.
- Measure the resistance between stability/traction control switch C280 pin-1 and pin-2, component side.
- Is the resistance less than 5 ohms?
Yes
GO to I3.
No
INSTALL a new stability/traction control switch. REFER to Stability/Traction Control Switch Service and Repair. TEST the system for normal operation.
-------------------------------------------------
I3 CHECK THE SWITCH CONTROL CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: PCM C175B.
- Measure the resistance between PCM C175B-8, circuit 959 (GY), harness side and stability/traction control switch C280-1, circuit 959 (GY), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to I4.
No
REPAIR circuit 959 (GY). TEST the system for normal operation.
-------------------------------------------------
I4 CHECK THE SWITCH CONTROL CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between stability/traction control switch C280-1, circuit 959 (GY), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to I5.
No
REPAIR circuit 959 (GY). TEST the system for normal operation.
-------------------------------------------------
I5 CHECK THE VOLTAGE TO THE STABILITY/TRACTION CONTROL SWITCH
- Ignition ON.
- Measure the voltage between stability/traction control switch C280-2, circuit 640 (RD/YE), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new PCM. REFER to Electronic Engine Controls Service and Repair. TEST the system for normal operation.
No
VERIFY CJB fuse 26 (10A) is OK. If OK, REPAIR circuit 640 (RD/YE). If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. Diagrams By Number
-------------------------------------------------