GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The theft deterrent control module produces the theft deterrent fuel and starter enable signal when ignition is ON and the proper transponder key value is detected. The powertrain control module (PCM) monitors the fuel and starter enable signal during crank. If the proper signal is present on the Class 2 Serial Data Circuit, the PCM enables the fuel delivery and starter operation in order to allow the engine to start. If the PCM has received a fuel disable password or an undecided password (theft deterrent system failure or attempted vehicle theft, DTC P1632 is set. The engine will not start or crank as long as the condition is present.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The powertrain control module (PCM) has received a fuel disable password or an undecided password from the theft deterrent control module.

Actions Taken When the DTC Sets

    • The vehicle will not start.
    • The powertrain control module sends a serial data message to the IPC to illuminate the SECURITY indicator.
    • The PCM will not illuminate the malfunction indicator lamp (MIL).
    • The PCM will store conditions which were present when the DTC set as failure records data only. This information will not be stored as freeze frame data.

Conditions for Clearing the MIL/DTC

    • A history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
    • The DTC can be cleared by using a scan tool.

Diagnostic Aids

DTC P1632 indicates that the PCM has received a fuel disable password or an undecided password from the vehicle theft deterrent control module. This condition can occur if an incorrect key is being used when attempting to start the vehicle or if there are other electronic devices accompanying the vehicle key's that may cause interference with the vehicle key transponder (other transponder type key's, fuel station transponder, etc.).

Test Description

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

  1. Verifies if the condition for setting a theft deterrent control module DTC is current.

  2. Verifies the conditions for setting DTC P1632 is current.

  3. Verifies if there are other electronic devices accompanying the vehicle key's that may cause interference with the vehicle key transponder (other transponder type key's, fuel station transponder, etc.).

Step

Action

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

Is DTC B2734, B2948, B2955, B2960, B3031 or B3055 set as a current code?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3

Is DTC P1632 set as a current code?

Go to Step 4

Go to Diagnostic Aids

4

Attempt to start the vehicle.

Does the vehicle start and run?

Go to Step 5

Go to Step 6

5

Inspect for electronic devices accompanying the vehicle key's that may cause interference with the vehicle key transponder (other transponder type key's, fuel station transponder, etc.).

Did you find and correct the condition?

Go to Step 8

Go to Step 6

6

Inspect for poor connections at the harness connector of the theft deterrent control 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 7

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 component procedure. Refer to Programming Theft Deterrent System Components .

Is the replacement complete?

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