For 1990-2009 cars

### Circuit Description

The theft deterrent control module checks the theft deterrent exciter module supply circuit for a constant voltage condition.

### Conditions for Running the DTC

The theft deterrent control module must see the ignition switch input. The theft deterrent control module can not have DTC B1327 set as a current DTC.

### Conditions for Setting the DTC

The theft deterrent control module requires 1 second to monitor the ignition key. After the first second, the VTD module turns off the power to the theft deterrent exciter module. If the theft deterrent control module senses the supply to the theft deterrent exciter module is 12 V for 1 second, the theft deterrent control module sets this DTC.

### Action Taken When the DTC Sets

• | The theft deterrent control module sends a class 2 message containing athe fuel disable password to the PCM.

• | The vehicle will not start.

• | The theft deterrent control module sends a class 2 message to the instrument cluster to illuminate the SECURITY indicator.

### Conditions for Clearing the MIL/DTC

The theft deterrent control module clears the current status of the DTC when it does not sense a 12 V condition on the theft deterrent exciter module supply circuit. The DTC will still be retrieved as current until the ignition switch is cycled. The DTC will become a history DTC at that time.

### Diagnostic Aids

Refer to Testing for Intermittent Conditions and Poor Connections and Testing for Electrical Intermittents in Wiring Systems.

### Test Description

The number below refers to the step number on the diagnostic table.

1. Make sure the good ground used is separate from the grounds used by the theft deterrent control module. Voltage measurement must not interfere with possible isolated module ground.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: Theft Deterrent System Schematics Connector End View Reference: Theft Deterrent System Connector End Views
1 | Did you perform the Theft Deterrent Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check - Theft Deterrent
2 |

1. Turn OFF the ignition.
2. Disconnect the theft deterrent exciter module.
3. Measure the voltage from the security system sensor supply circuit to a good ground.

Does the voltage measure near the specified value?

0 V

Go to Step 4

Go to Step 3

3 | Test the security system sensor supply circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 5
4 | Inspect for poor connections at the harness connector of the theft deterrent exciter module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 6
5 | Inspect for poor connections at the harness connector of the vehicle theft deterrent control module (VTD). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems . Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 7
6 | Replace the theft deterrent exciter module. Refer to Theft Deterrent Exciter Module Replacement . Did you complete the replacement? | -- | Go to Step 8 | --
7 | Important: If a 10 Minute or 30 Minute Re-Learn Procedure is performed, all keys not learned at that time will be erased and will not be recognized. Perform the Adding Keys procedure on all keys or instruct the customer how to perform the Adding Keys procedure. Refer to Adding Keys .

1. Replace the theft deterrent control module . Refer to Theft Deterrent Module Replacement .
2. With a scan tool, perform the Set Up New VTD Module procedure in the Vehicle Theft Deterrent, Special Functions data list.
3. Perform the Programming Theft Deterrent System Components procedure. Refer to Programming Theft Deterrent System Components .

Did you complete the replacement?

--

Go to Step 8

--

8 |

1. Use the scan tool in order to clear the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK