Pinpoint Test D: No Communication With The Lighting Control Module (LCM)
Test Step
D1 CHECK CIRCUIT 640 (RD/YE) FOR VOLTAGE
- Key in OFF position.
- Disconnect: LCM C2145a.
- Key in ON position.
- Measure the voltage between LCM C2145a pin 17, circuit 640 (RD/YE), harness side and ground.
- Is the voltage greater than 10 volts?
Result / Action to Take
Yes
GO to D2.
No
REPAIR the circuit. REPEAT the self-test.
Test Step
D2 CHECK CIRCUIT 964 (DB/LG) FOR VOLTAGE
- Key in OFF position.
- Measure the voltage between LCM C2145b pin 6, circuit 964 (DB/LG), harness side and ground.
- Is the voltage greater than 10 volts?
Result / Action to Take
Yes
GO to D3.
No
REPAIR the circuit. REPEAT the self-test.
Test Step
D3 CHECK CIRCUIT 676 (PK/OG) C2145A FOR AN OPEN
- Measure the resistance between LCM C2145a pin 23, circuit 676 (PK/OG), harness side and ground.
- Is the resistance less than 5 ohms?
Result / Action to Take
Yes
GO to D4.
No
REPAIR the circuit. REPEAT the self-test.
Test Step
D4 CHECK CIRCUIT 676 (PK/OG) C2145C FOR AN OPEN
- Key in OFF position.
- Measure the resistance between LCM C2145c pin 13, circuit 676 (PK/OG), harness side and ground.
- Is the resistance less than 5 ohms?
Result / Action to Take
Yes
GO to D5.
No
REPAIR the circuit. REPEAT the self-test.
Test Step
D5 CHECK FOR CORRECT LCM OPERATION
- Disconnect all LCM connectors.
- Check for:
- corrosion
- pushed-out pins
- Connect all LDM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Result / Action to Take
Yes
INSTALL a new LCM. REFER to MODULE-LIGHTING CONTROL (LCM) . TEST the system for normal operation.
No
The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.