2001 Chevrolet/Geo Camaro  

DTC P1629

Circuit Description

The body control module (BCM) produces the theft deterrent fuel enable signal when ignition is ON and the proper key resistor pellet is sensed. The powertrain control module (PCM) monitors the fuel enable signal during crank. If the proper signal is present on the theft deterrent fuel enable circuit, the PCM enables fuel delivery to allow the engine to start. If the PCM detects that the fuel enable signal is not present or incorrect during engine crank, DTC P1629 will be set. DTC P1629 can cause a no-start condition or normal operation depending on when the loss of the fuel enable signal was detected. The engine will continue to start and run if the condition that set DTC P1629 occurred after the BCM sensed the proper key resistor pellet and signaled the PCM to continue fuel delivery. The engine will start and immediately stall if the condition that set DTC P1629 occurred before the BCM sensed the proper key resistor pellet. With this condition present, the PCM will inhibit fuel delivery and the BCM will disable the starter.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC
Action Taken When the DTC Sets
Conditions for Clearing the MIL/DTC
Diagnostic Aids

Many situations may lead to an intermittent condition. The following list is to be used as a guide to assist in detecting an intermittent:

Test Description

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

  1. This step tests the integrity of the ignition key resistor circuits.

Step

Action

Values

Yes

No

Schematic Reference: Theft Deterrent System Schematics

1

Did you perform A Diagnostic System Check-Theft Deterrent?

--

Go to Step 2

Go to Diagnostic System Check - Theft Deterrent

2

  1. Install a scan tool.
  2. Turn on the ignition with the engine off.
  3. Select the PCM Display DTCs feature on the scan tool.

Does the scan tool display DTC P1629 as a current DTC?

--

Go to Step 3

Go to Testing for Intermittent and Poor Connections in Wiring Systems

3

  1. Turn OFF the ignition.
  2. Disconnect the body control module (BCM).
  3. Turn ON the ignition.
  4. Measure the voltage on the vehicle theft deterrent fuel enable circuit using a DMM that is connected to a good ground.

Does the voltage measure at or near the specified value?

5 V

Go to Step 4

Go to Step 6

4

  1. Turn on the J 35628-A Pass/Vats Interrogator.
  2. Insert the ignition key into the J 35628-A .

Does the tool indicate a valid code (1-15)?

--

Go to Step 5

Go to Step 12

5

  1. Connect the J 35628-A to the ignition key resistor signal circuit and the ignition key resistor low reference circuit at the harness connector of the BCM.
  2. Insert the key into the ignition switch and turn to the ON position.
  3. Read the code on the J 35628-A display.

Does the code received match the code from the previous step?

--

Go to Step 8

Go to Step 9

6

Test the vehicle theft deterrent fuel enable circuit for an open, short to ground, or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 7

7

Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 10

8

Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 11

9

Test the following circuits for an open, high resistance, short to ground or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

  • Ignition key resistor signal circuit
  • Ignition key resistor low reference circuit

Did you find and correct the condition?

--

Go to Step 14

Go to Step 13

10

Important

When replacing the PCM, perform the programming procedure. Refer to Powertrain Control Module (PCM) Programming 3.8L or Powertrain Control Module (PCM) Programming 5.7L in Engine Controls.

Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement 3.8L or Powertrain Control Module (PCM) Replacement 5.7L in Engine Controls.

Did you complete the replacement?

--

Go to Step 14

--

11

Important

When replacing the BCM, perform the relearn procedure. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

--

Go to Step 14

--

12

Replace the ignition key. Refer to Replacing Keys .

Did you complete the repair?

--

Go to Step 14

--

13

Replace the ignition lock cylinder. Refer to Ignition Lock Cylinder Replacement - On Vehicle in Steering Wheel and Column-Tilt.

Did you complete the repair?

--

Go to Step 14

--

14

  1. Use the scan tool in order to clear DTCs.
  2. Attempt to start the vehicle.

Does the vehicle start and run?

--

System OK

Go to Step 2