P0686-ECM VOLTAGE ERROR LOW

For a complete wiring diagram Refer to Section 8W

When Monitored:
With the ignition on or the engine running.
Set Condition:
The ECM detects low battery voltage.

Possible Causes

CHECKING ECM POWER AND GROUNDS

ECM

INTERMITTENT CONDITION

Diagnostic Test

1.CHECK FOR ACTIVE DTC

NOTE: If the ECM detects and stores a DTC, the ECM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.

NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.

NOTE: This DTC may be caused by a charging system problem. Refer to the Service Information and verify proper charging system operation before continuing.

Did this DTC set again?

Yes

Go To2

Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

2.CHECK POWER AND GROUNDS

Were any problem found with the ECM powers and grounds?

Yes

Repair as necessary.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

Replace and program the Engine Control Module in accordance with the Service Information.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).