ESP/TCS SWITCH CIRCUIT
For a complete wiring diagram Refer to Section 8W.
- When Monitored:
With the ignition on.
- Set Condition:
When the Anti-Lock Brake Module indicates that the ESP/TCS Switch is low for 30 seconds.
| Possible Causes |
| STUCK CLOSED ESP/TCS SWITCH |
| (Z906) GROUND CIRCUIT OPEN |
| (B46) ESP/TCS CONTROL SWITCH SENSE CIRCUIT SHORTED TO GROUND |
| ANTI-LOCK BRAKE MODULE |
Diagnostic Test
1. ESP/TCS SWITCH CIRCUITNOTE: If any other DTCs are present they must be repaired before continuing.
Turn the ignition on.
Turn the ESP/TCS switch on then off.
Check for car icon on solid in cluster and pressing ESP/TCS switch does not change state.
With the scan tool, read the switch state for the ESP/TCS switch without pressing the switch, read and record DTCs.
Does the scan tool display switch state indicating pressed?
Yes
- Go To 2
No
- The condition that caused the symptom is currently not present. Inspect the related wiring for a possible intermittent condition. Look for any chafed, pierced, pinched, or partially broken wires.
- Refer to the ABS-INTERMITTENT CONDITION TEST. (Refer to 5 - BRAKES - DIAGNOSIS AND TESTING).
2. (Z906) OPEN CIRCUIT
Turn the ignition off.
Disconnect the ESP/TCS switch.
Using a 12–volt test light connected to 12–volts, check the (Z906) ground circuit.
Does the test light illuminate brightly?
Yes
- Go To 3
No
- Repair (Z906) ground circuit for an open circuit or high resistance.
- Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).
3. CHECK FOR A STUCK ESP/TCS SWITCH
Turn the ignition off.
Measure the internal resistance of the ESP/TCS Switch between the (B46) ESP/TCS control circuit and (Z906) Ground circuit.
Is the resistance below 5.0 ohms?
Yes
- Replace the ESP/TCS Switch in accordance with the Service Information.
- Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).
No
- Go To 4
4. ESP/TCS CONTROL CIRCUIT
Turn the ignition off.
Disconnect the ESP/TCS Switch.
Disconnect the Anti-Lock Brake Module harness connector.
Measure the resistance of the (B46) ESP/TCS control circuit to ground.
Is the resistance below 5.0 ohms?
Yes
- Repair the (B46) ESP/TCS control circuit for a short to ground.
- Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).
No
- Replace the Anti-Lock Brake Module in accordance with the Service Information.
- Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).