Auto Shutdown (ASD) Relay Control Circuit

Name of Code:
Auto Shutdown Relay Control Circuit

When Monitored:
With the ignition key on and battery voltage greater than 10 volts.

Set Condition:
An open or shorted condition is detected in the auto shutdown relay control circuit.

Theory of Operation:
The automatic shutdown relay (ASD) controls the 12 volt source to the fuel injectors, ignition coil(s), oxygen sensors, and the generator. The relay is located in the power distribution center (PDC). One side of the relay control coil is supplied with 12 volts when the ignition switch is turned to the run position. The circuit is completed when the other side of the relay coil is grounded by the powertrain control module (PCM). The PCM grounds the relay when the ignition switch is in either the run or crank position and engine RPM is detected. If engine RPM is not detected, the PCM will remove the ASD relay control circuit ground.

Possible Causes:
- Relay coil open or shorted
- Fused ignition switch output circuit open
- Auto shutdown relay control circuit open or shorted
- Inoperative circuit driver in powertrain control module
- PCM failure
- Connector terminals
- Connector wires