Shift Interlock System: Overview Pontiac Sunfire I

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Test Description

The numbers below refer to the step numbers on the diagnostics, table.

2. Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.

3. If no DTCs are present, refer to the symptom list of further diagnostics.

4. The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.

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

2. Listen for an audible click when the automatic transmission shift lock control solenoid operates. Command both the ON and OFF states. Repeat the commands as necessary.

3. Tests for voltage at the ignition 1 voltage circuit of the automatic transmission shift lock control solenoid.

4. Verifies that the BCM is providing a ground to the automatic transmission shift lock control solenoid.

5. Tests if a ground is constantly being applied to the automatic transmission shift lock control solenoid.

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

2. Listen for an audible click when the automatic transmission shift lock control solenoid operates. Command both the ON and OFF states. Repeat the commands as necessary.

3. Tests for voltage at the ignition 1 voltage circuit of the automatic transmission shift lock control solenoid.

4. Verifies that the BCM is providing a ground to the automatic transmission shift lock control solenoid.

5. Tests if ground is constantly being applied to the automatic transmission shift lock control solenoid.

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Symptoms - Automatic Transmission Shift Lock Control

1. Perform the «DIAGNOSTIC SYSTEM CHECK - AUTOMATIC TRANSMISSION SHIFT LOCK CONTROL»(ref-189102-S25661597082005090600000) before using the Symptom Tables in order to verify that all of the following are true: There are no DTCs set. The control module(s) can communicate via the serial data link.
2. Review the system operation in order to familiarize yourself with the system functions. Refer to «AUTOMATIC TRANSMISSION SHIFT LOCK CONTROL DESCRIPTION AND OPERATION»(ref-189102-S18474569882005090600000) .

Automatic Transmission Shift Lock Control Description and Operation

The automatic transmission shift lock control system is a safety device that prevents an inadvertent shift out of PARK when the engine is running. The driver must press the brake pedal before moving the shift lever out of the PARK position. The system consists of thew following components

1. The automatic transmission shift lock control solenoid.
2. The body control module (BCM)
3. The powertrain control module (PCM)

With the ignition in the ON position, battery positive voltage is supplied to the automatic transmission shift lock control solenoid. The automatic transmission shift lock control solenoid receives a ground from the BCM. When the automatic transmission shift lock control solenoid is energized, the shift lever mechanically locked in the PARK position. When the driver presses the brake pedal the PCM sends a class 2 serial data message to the BCM. The BCM turns OFF the ground control circuit and this de-energizes the automatic transmission shift lock control solenoid. When the automatic transmission shift lock control solenoid is de-energized, the shift lever may be moved out of the PARK position. The BCM determines transaxle shift lever position through a class 2 serial data message from the PCM. The PCM receives inputs from the park/neutral position switch and determines shift lever position. When the BCM receives this information and determines that the shift lever is out of the PARK position, the automatic transmission shift lock control solenoid ground is opened.