For 1990-2009 cars

### Schematic

Refer to

#### Pass Key III Module

Theft Deterrent System Components
Vehicle Theft Deterrent (VTD) Description
Cell 133: G200, G302
DLC Schematic
Stop Lamp, Hazard, and Pass Key Fuses, FRT HVAC MI BLWR and Headlamp Circuit Breakers
IGN, SIR, T/S/G, Cruise, and PCM/Pass Key 1 Cluster Fuses
IGN, SIR, T/S/G, Cruise, and PCM/Pass Key 1 Cluster Fuses
Cell 14: G200
.

### Circuit Description

When an ignition key is inserted into the ignition lock cylinder, the transponder embedded in the head of the key is energized by the exciter coils surrounding the ignition lock cylinder. The energized transponder transmits a signal that contains its unique value, which is received by the VTD (Pass Key® III) Module . The VTD (Pass Key® III) Module then compares this value to a value stored in memory (learned key code). If the value is correct the VTD (Pass Key® III) Module sends the enable password via the class 2 serial data circuit to the PCM.

### Conditions for Running the DTC

The ignition switch must be in RUN.

### Conditions for Setting the DTC

If the code from the ignition key does not match one stored in memory, the VTD (Pass Key® III) Module sets this DTC. This code indicates the use of a key with a transponder that has not been learned by the VTD (Pass Key® III) Module. The vehicle considers this to be a theft attempt.

### Action Taken When the DTC Sets

• | The VTD (Pass Key® III) Module sends a class 2 message containing a disable password to the PCM.

• | The vehicle will not start.

• | The VTD (Pass Key® III) Module sends a class 2 message to the instrument cluster to flash the SECURITY indicator.

### Conditions for Clearing the MIL/DTC

The VTD (Pass Key® III) Module clears the current status of the DTC when it senses a valid, memorized, key code from the ignition key (transponder).

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. To set this code, a key with a working transponder was read by the VTD (Pass Key® III) Module. For that key to operate the vehicle perform a 10-minute or 30-minute re-learn procedure.

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform A Vehicle Diagnostic System Check - Theft Deterrent ? | Go to Step 2 | Go to Diagnostic System Check - Theft Deterrent
2 | Important: If you perform a 10-minute or 30-minute re-learn procedure, all keys not learned at that time will be erased and will not be recognized. Perform the Quick Learn Procedure on all keys or instruct the customer how to perform the Quick Learn Procedure.

Perform the VTD (Pass Key® III) Module learn Procedure. Refer to Programming Theft Deterrent System Components .

Is the procedure complete?

Go to Step 3

--

3 |

1. Use a scan tool in order to clear the DTC's.
2. Attempt to start the vehicle.

Does the DTC reset?

Go to Step 2

System OK