P1564
Diagnostic Chart:
Electrical:
CIRCUIT DESCRIPTION
A complete loss of battery voltage at the ECM will cause a no start with no MIL. However, an intermittent loss of B+ can set this DTC. Also, if the ECM has been disconnected, or B+ was interrupted during a service procedure, this DTC may set.
CONDITIONS FOR RUNNING THE DTC
Engine cranking
CONDITIONS FOR SETTING THE DTC
The ECM has detected a loss of battery voltage.
ACTION TAKEN WHEN THE DTC SETS
The ECM will not illuminate the Malfunction Indicator Lamp (MIL).
CONDITIONS FOR CLEARING THE MIL/DTC
^ The DTC clears after forty consecutive warm-up cycles if no failures report by this diagnostic or any other non-emission related diagnostic. The scan tool clears the MIL/DTC.
DIAGNOSTIC AIDS
Use the Connector Test Adapter Kit J 35616-A for any test that requires probing the ECM harness connector or a component harness connector. Using this kit will prevent damage to the harness connector terminals.
Check for poor connections at the ECM or at the component. Inspect the harness connectors for any backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. Refer to Overall Vehicle Information / Diagrams / Diagnostic Aids for Checking Terminal Contact procedure.
Refer to Symptoms / Intermittents. Testing and Inspection
TEST DESCRIPTION
If the engine starts and runs, the fault is not present at this time. Check for any intermittent connections or an intermittent circuit problem on the B+ supply circuit to the ECM.