P068B-ECM RELAY OFF TOO LATE
For a complete wiring diagram Refer to Section 8W
Theory of Operation
When the ignition switch is turned off (ignition power removed from ECM) the ECM continues to drive the ECM/ASD relay on for approximately 20–40 seconds. This period of time is the After-Run Mode of operation. During After-Run the ECM performs several internal and external checks. When After-Run is complete, the ECM switches off the ECM/ASD relay driver and powers off the engine system.
- When Monitored:
When the ignition is turned off, during AFTER-RUN mode of operation.
- Set Condition:
The internal ECM timer determines that the ASD Relay remained on for 2.0 seconds once AFTER-RUN mode of operation has been completed.
| Possible Causes |
| CHECK FOR OTHER DTCS |
| INTERMITTENT CONDITION |
| SUBSTITUTE ASD RELAY |
| (K51) ASD RELAY CONTROL CIRCUIT SHORTED TO GROUND INTERMITTENTLY |
| ASD RELAY OUTPUT CIRCUIT SHORTED TO VOLTAGE |
| ENGINE CONTROL MODULE |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
Diagnostic Test
1. CHECK FOR OTHER DTCSTurn the ignition on.
With the scan tool, check for additional DTCs.
Are other DTCs present?
Yes
- Refer to the Symptom List for diagnosis of the other DTCs before continuing.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To2
2. CLEAR CODE AND CHECK IF THE DTC RESETS
Perform several ignition key cycles, pausing for at least 40 seconds between each cycle.
Turn the ignition on.
With the scan tool, read ECM DTCs.
Did this DTC set again?
Yes
- Go To 3
No
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
3. ASD RELAY
Turn the ignition off.
Install a known good relay in place of the ASD Relay.
Turn the ignition on.
With the scan tool, erase DTCs.
Perform several ignition key cycles, pausing for at least 40 seconds between each cycle.
Turn the ignition on.
With the scan tool, read ECM DTCs.
Did this DTC set again?
Yes
- Go To 4
No
- Replace the ASD Relay.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
4. (K51) ASD RELAY CONTROL CIRCUIT SHORTED TO GROUND INTERMITTENTLY
Turn the ignition off.
Remove the ASD Relay from the TIPM.
Disconnect the ECM harness connectors.
Measure the resistance between ground and the (K51) ASD Relay Control circuit while wiggling the wiring harness and connectors.
Was the resistance below 1000 ohms at any time while wiggling the wiring harness and connectors?
Yes
- Repair the (K51) ASD Relay Control circuit for an intermittent short to ground.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To 5
5. ASD RELAY OUTPUT CIRCUIT SHORTED TO VOLTAGE
Turn the ignition on.
Measure the voltage of the ASD Relay Output circuit.
Is the voltage below 1.00 volt?
Yes
- Go To 6
No
- Repair the ASD Relay Output circuit for a short to voltage.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
6. CHECK THE ECM POWER AND GROUND CIRCUITS
Turn the ignition off.
Install the ASD relay.
Refer to symptom CHECKING THE ECM POWER AND GROUNDS and verify proper Ignition, Battery and Ground circuits at the ECM.
Were any problem found with the ECM Ignition, Battery or Ground circuits?
Yes
- Repair or replace as necessary.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Replace and program the Engine Control Module in accordance with the Service Information.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)