For 1990-2009 cars

### Circuit Description

Internal defects in the theft deterrent module (TDM) set DTC 55.

### Conditions for Setting the DTC

Theft deterrent module hardware failure (EEPROM, RAM, ROM defective).

### Action Taken When the DTC Sets

The engine will not start.

### Conditions for Clearing the DTC

• | Replacing the theft deterrent module.

• | A history DTC will clear after 20 consecutive ignition cycles if the condition for the fault is no longer present.

• | Use a scan tool in order to clear this DTC.

### Diagnostic Aids

• | Before replacing the TDM, always inspect the power and ground circuits to the module.

• | Replace the TDM if the power and ground circuits are OK.