Contents Wiring diagrams Section: Automatic Trans All sections

Shift Interlock System: Other Saturn ION I

Automatic Trans ~295 words

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Shift Lever Does Not Move with Brake Pedal Depressed

StepActionYesNo
Schematic Reference: Automatic Transmission Shift Lock Control Schematics Connector End View Reference: Computer/Integrating Systems Connector End Views in Computer/Integrating Services DEFINITION: Transmission shift lever will not move out of the PARK position with the Ignition on and the brake pedal pressed.
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Turn ON the ignition, with the engine OFF. Press and hold the brake pedal. Attempt to move the shift lever out of the PARK position. Does the shift lever move out of the PARK position?Go to Testing for Intermittent Conditions and Poor Connections in Wiring SystemsGo to Step 3
3Turn OFF the ignition. Install a scan tool. Turn ON the ignition, with the engine OFF. Press and hold the brake pedal. With the scan tool, turn the brake to shift relay output control ON in the body control module (BCM) output control data list. Attempt to move the shift lever out of the PARK position. Does the shift lever move out of the PARK position?Go to Step 4Go to Step 6
4With the scan tool, observe the brake switch input in the BCM data display list. Press and release the brake pedal several times while observing the scan tool. Does the brake input display ON and OFF with the brake pedal operation?Go to Step 5Go to Diagnostic Starting Point - Lighting Systems in Lighting Systems
5With the scan tool observe the gear position parameter in the powertrain control module (PCM) data list. Does the scan tool indicate PARK position?Go to Step 10Go to Diagnostic Starting Point - Engine Controls in Engine Controls - 2.2L (L61)
6Turn OFF the ignition. Connect a test lamp between the automatic transmission (A/T) shift lock control solenoid control circuit and a good ground. Turn ON the ignition, with the engine OFF. With a scan tool, command the shift lock control relay output ON in the BCM output control data list. Does the test lamp illuminate?Go to Step 7Go to Step 8
7Test the shift lock control solenoid ground circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 13Go to Step 9
8Test the A/T shift lock control circuit for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 13Go to Step 10
9Inspect for poor connections as the harness connector of the A/T shift lock control solenoid. 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 13Go to Step 11
10Inspect for poor connections as the harness connector of the BCM. 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 13Go to Step 12
11Replace the A/T shift lock control solenoid. Refer to Shift Lock Solenoid/Switch Assembly Replacement . Did you complete the replacement?Go to Step 13
12IMPORTANT: Perform the set up procedures for the BCM. Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.Did you complete the replacement?Go to Step 13
13Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Step 3
IMPORTANT
Perform the set up procedures for the BCM.

Shift Lever Does Not Move with Brake Pedal Depressed

Shift Lever Can Be Moved without Brake Pedal Depressed

StepActionYesNo
Schematic Reference: Automatic Transmission Shift Lock Control Schematics Connector End View Reference: Computer/Integrating Systems Connector End Views in Computer/Integrating Systems DEFINITION: Transmission shift lever does not lock in the PARK position with the ignition ON and the brake pedal not depressed.
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Apply the parking brake and block the wheels. Turn ON the ignition, with the engine OFF. Attempt to move the shift lever out of the PARK position without pressing the brake pedal. Does the shift lever move out of the PARK position?Go to Step 3Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
3Turn OFF the ignition. Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool observe the BTSI parameter in the body control module (BCM) data list. Ensure the brake pedal is not depressed. Does the scan tool display a LOCKED status for the brake to shift parameter?Go to Step 5Go to Step 4
4With a scan tool observe the brake switch input in the BCM data list. Does the scan tool display an OFF status for the brake switch input parameter?Go to Step 8Go to Diagnostic Starting Point - Lighting Systems in Lighting Systems
5Turn OFF the ignition. Disconnect the automatic transmission (A/T) shift lock control solenoid electrical connector. Turn ON the ignition, with the engine OFF. Press and hold the brake pedal. Attempt to move the shift lever out of the PARK position. Does the shift lever move out of the PARK position?Go to Step 7Go to Step 6
6Test the A/T shift lock control solenoid control circuit for a short to power. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 8
7Inspect for poor connections at the harness connector of the A/T shift lock control solenoid. 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 11Go to Step 9
8Inspect for poor connections at the harness connector of the BCM. 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 11Go to Step 10
9Replace the A/T shift lock control solenoid. Refer to Shift Lock Solenoid/Switch Assembly Replacement . Did you complete the replacement?Go to Step 11
10IMPORTANT: Perform the set up procedures for the BCM. Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.Did you complete the replacement?Go to Step 11
11Operate the system in order to verify the repair. Did you correct the condition?System OKGo to Step 2
IMPORTANT
Perform the set up procedures for the BCM.

Shift Lever Can Be Moved without Brake Pedal Depressed

Automatic Transmission Shift Lock Control System

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 the following components

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

The BCM controls the voltage to the shift lock control solenoid through the shift lock control solenoid controlled voltage circuit. The following conditions must be met before the BCM will supply voltage to the shift lock control solenoid

  1. The ignition is in the ON position.
  2. The TCM sends a class 2 message to the BCM indicating the transmission is in the PARK position.
  3. The BCM receives a brake applied input from the stop lamp switch.

Since the shift lock control solenoid is permanently grounded, the BCM supplies voltage to the automatic transmission shift lock control solenoid, releasing the mechanical lock on the shift lever as the solenoid energizes. This allows the driver to move the shift lever out of the PARK position. When the brake pedal is not applied, the BCM switches the ground of the shift lock control solenoid OFF, de-energizing the shift lock control solenoid. The de-energized solenoid mechanically locks the shift lever in the PARK position.