MIL Does Not Come ON with Ignition Switch in ON Position and Engine Stopped (but Engine Can Be Started)
MIL Does Not Come ON with Ignition Switch in ON Position and Engine Stopped (but Engine Can Be Started)
Wiring Diagram
Circuit Description
When the ignition switch is turned ON, ECM causes the main relay to turn ON (close the contact point). Then, ECM being supplied with the main power, transmits indication ON signal of MIL to combination meter in order to turn MIL ON. And then, combination meter turns MIL ON. When the engine starts to run and no malfunction is detected in the system, ECM transmits MIL indication OFF signal to combination meter in order to turn MIL OFF. And then, combination meter turns MIL OFF, but if a malfunction was or is detected, MIL remains ON even when the engine is running.
Troubleshooting
1. MIL power supply check
Turn ignition switch to ON position.
Do other warning lights come ON?
YES -
Go to Step 2.
NO -
Go to Step 5.
2. DTC check in ECM
Connect scan tool to DLC with ignition switch turned OFF.
Turn ON ignition switch and check DTC in ECM.
Is there DTC(s) U0073 and/or U0121?
YES -
Go to applicable DTC troubleshooting.
NO -
Go to Step 3.
3. DTC check in ESP(R) control module
Check DTC in ESP(R) control module.
Is there DTC(s) U0073 and/or U0100?
YES -
Go to applicable DTC troubleshooting.
NO -
Go to Step 4.
4. DTC check in BCM
Check DTC in BCM.
Is there DTC U0100?
YES -
Go to applicable DTC troubleshooting.
NO -
Substitute a known-good combination meter and recheck. If MIL still remains OFF, substitute a known-good ECM and recheck.
5. CAN communication line circuit check
Check CAN communication line circuit between control modules for open, short, high resistance and connections according to Step 5 under Symptom Related Diagnostic Procedures Troubleshooting for Communication Error with Scan Tool Using CAN.
Is circuit in good condition?
YES -
Go to Step 6.
NO -
Repair or replace.
6. "METER" fuse check
Turn ignition switch to OFF position.
Check for fuse blown at "METER" fuse in junction block.
Is "METER" fuse in good condition?
YES -
Go to Step 7.
NO -
Replace "METER" fuse and check for short.
7. Combination meter power supply check
Remove combination meter. Service and Repair
Check for proper connection to combination meter connector at "G241-31" and "G241-16" terminals.
If OK, then turn ignition switch to ON position and measure voltage between combination meter connector at "G241-31" terminal and vehicle body ground.
Is it 10 - 14 V?
YES -
Go to Step 8.
NO -
"RED/BLK" wire is open circuit.
8. Combination meter circuit check
Turn ignition switch to OFF position.
Measure resistance between "G241-16" terminal of combination meter connector and vehicle body ground.
Is resistance 1 ohms or less?
YES -
Substitute a known-good combination meter and recheck. If MIL still remains OFF, substitute a known-good ECM and recheck.
NO -
"BLK" wire is open or high resistance circuit.