Starter Inhibit Relay Circuit Diagnosis

Circuit Description
The Vehicle Theft Deterrent System (VTD) is incorporated within the Body Control Module (BCM). The PCM has the ability to disable starter operation if conditions inappropriate for starter operation exist. The PCM disables the starter if the engine is running, if a correct VTD password is not received from the BCM or if the vehicle operator attempts to engage the starter for an extended period of time.

The PCM controlled starter system consists of the following components:
^ Starter enable relay.
^ The Transaxle Range/Park Neutral Position switch.
^ The ignition switch.
^ The starter solenoid.
^ The PCM.

Diagnostic Aids
The PCM Controlled Starter Diagnosis table is intended to identify electrical malfunctions that can occur with the system. For additional system diagnosis, refer to Starting and Charging.

Check for the following conditions:
^ Poor connection at the PCM, the starter enable relay, the Transaxle Range/PNP switch, the ignition switch or the starter solenoid.
Inspect harness connectors for the following conditions:
- Backed out terminals.
- Improper mating.
- Broken locks.
- Improperly formed or damaged terminals.
- Poor terminal to wire connection.
^ Damaged harness.
Inspect the wiring harness for damage.
^ Either of the following conditions can cause the PCM to disable starter operation:
- The engine has been running for longer than 10 seconds.
- The starter has been continuously engaged for longer than 15 seconds.
- A correct VTD password has not been received from the BCM.

Test Description
Number(s) below refer to step number(s) in the diagnostic table.
2. If the engine cranks with the vehicle ignition switch in the OFF position, there are three possible malfunction areas: malfunctioning CRANK relay, a short to voltage in the Starter feed circuit, or a short to voltage in the starter enable circuit.
4. Determines if the starter feed or the starter enable control circuit is shorted to voltage. If the engine does not crank with the relay removed, then the relay or the starter enable circuit is suspect.
16. Check for proper ignition positive voltage on the starter enable control circuit.
17. Checks for proper current draw through the relay. Excess current will cause an inoperative PCM driver circuit.
30. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Read Only Memory (EEPROM) When the PCM is being replaced, the new PCM must be programmed.