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Shift Interlock System Chevrolet Colorado I

Automatic Trans 1 illustration ~2226 words

Scheme 92

Scheme 92: Shift Lock Control Schematics
Scheme 92: Shift Lock Control Schematics

DIAGNOSTIC CODE INDEX

DTCDescription
DTC B2707B2707: Gearshift Unlock Circuit Low
DTC B2708B2708: Gearshift Unlock Circuit High

DIAGNOSTIC CODE INDEX

Diagnostic Starting Point - Automatic Transmission Shift Lock Control

Begin the system diagnosis with the Diagnostic System Check - Vehicle . The Diagnostic System Check will provide the following information

  1. The identification of the control modules which command the system
  2. The ability of the control modules to communicate through the serial data circuit
  3. The identification of any stored diagnostic trouble codes (DTCs) and their status

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.

Diagnostic Instructions

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Shift Lock Control Solenoid ControlB27071B2708
Shift Lock Control Solenoid Ground1
1. Unable to move shift lever with brake level depressed.

DTC B2707

Circuit/System Description

The body control module (BCM) controls the automatic transmission shift lock control solenoid by providing a battery positive voltage to the solenoid. The BCM utilizes a smart driver to control the voltage supply circuit to the automatic transmission shift lock control solenoid. The smart driver monitors the voltage and current flow of the control circuit.

Conditions for Running the DTC

  1. The ignition switch is in the ON position.
  2. The brake pedal is pressed.
  3. The transmission is in the PARK position.

Conditions for Setting the DTC

The DTC sets if there is a short to ground in the automatic transmission shift lock control solenoid control circuit.

Action Taken When the DTC Sets

The BCM will not attempt to enable the voltage supply circuit of the automatic transmission shift lock control solenoid until the next key cycle.

Conditions for Clearing the DTC

  1. A current DTC B2705 will clear when the malfunction is no longer present and the ignition switch is cycled.
  2. A history DTC will clear after 100 ignition cycles with no current DTC active during the 100 ignition cycles.

Reference Information

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Ignition ON, vehicle in PARK, observe the scan tool TCM TR SW parameter. The parameter should indicate PARK. If not the specified value, refer to «Range Selector Displays Incorrect Range»(/chevrolet/colorado/i-2004-2012/remont/automatic-trans/#how-to-overhaul-the-automatic-transmission-4l60-e4l65-e4l70-e-removal-installation-service-troubleshooting-diagnosis) .
  2. Observe the scan tool TCM Brake Switch parameter while pressing and releasing the brake pedal. The parameter should change between Applied and Released. If the parameter does not change between the specified values, refer to «Stop Lamps Malfunction»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems) .

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the shift lock control solenoid.
  2. Ignition OFF, test for less than 1.0 ohm between the ground circuit terminal B and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Install a test lamp between the ground circuit terminal B and the control circuit terminal A.
  4. Ignition ON, command the scan tool BCM Brake to Shift Relay output control ON and OFF. The test lamp should turn ON and OFF as commanded. If the test lamp is always ON, test the control circuit for short to voltage. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the control circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  5. If the circuit tests normal, replace the transmission control.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Automatic Transmission Shift Lock Control Actuator Replacement»(/chevrolet/colorado/i-2004-2012/remont/automatic-trans/#shift-interlock-system)
  2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Shift Lock Control Solenoid ControlB27071B2708
Shift Lock Control Solenoid Ground1
1. Unable to move shift lever with brake level depressed.

DTC B2708

The body control module (BCM) controls the automatic transmission shift lock control solenoid by providing a battery positive voltage to the solenoid. The BCM utilizes a smart driver to control the voltage supply circuit to the automatic transmission shift lock control solenoid. The smart driver monitors the voltage and current flow of the control circuit.

  1. The ignition switch is in the ON position.
  2. The brake pedal is pressed.
  3. The transmission is in the PARK position.

The DTC sets if there is a short to ground in the automatic transmission shift lock control solenoid control circuit.

The BCM will not attempt to enable the voltage supply circuit of the automatic transmission shift lock control solenoid until the next key cycle.

  1. A current DTC B2705 will clear when the malfunction is no longer present and the ignition switch is cycled.
  2. A history DTC will clear after 100 ignition cycles with no current DTC active during the 100 ignition cycles.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, vehicle in PARK, observe the scan tool TCM TR SW parameter. The parameter should indicate PARK. If not the specified value, refer to «Range Selector Displays Incorrect Range»(/chevrolet/colorado/i-2004-2012/remont/automatic-trans/#how-to-overhaul-the-automatic-transmission-4l60-e4l65-e4l70-e-removal-installation-service-troubleshooting-diagnosis) .
  2. Observe the scan tool TCM Brake Switch parameter while pressing and releasing the brake pedal. The parameter should change between Applied and Released. If the parameter does not change between the specified values, refer to «Stop Lamps Malfunction»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems) .
  1. Ignition OFF, disconnect the harness connector at the shift lock control solenoid.
  2. Ignition OFF, test for less than 1.0 ohm between the ground circuit terminal B and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Install a test lamp between the ground circuit terminal B and the control circuit terminal A.
  4. Ignition ON, command the scan tool BCM Brake to Shift Relay output control ON and OFF. The test lamp should turn ON and OFF as commanded. If the test lamp is always ON, test the control circuit for short to voltage. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the control circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  5. If the circuit tests normal, replace the transmission control.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Automatic Transmission Shift Lock Control Actuator Replacement»(/chevrolet/colorado/i-2004-2012/remont/automatic-trans/#shift-interlock-system)
  2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup and programming

Symptoms - Automatic Transmission Shift Lock Control

IMPORTANTReview the system operation in order to familiarize yourself with the system functions. Refer to Automatic Transmission Shift Lock Control Description and Operation .

Visual/Physical Inspection

  1. Inspect for aftermarket devices which could affect the operation of the automatic transmission shift lock control system. Refer to «Checking Aftermarket Accessories»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__checking-aftermarket-accessories) .
  2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

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

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Shift Lock Control Solenoid ControlB27071B2708
Shift Lock Control Solenoid Ground1
1. Unable to move shift lever with brake level depressed.

Transmission Control Lever Malfunction

The body control module (BCM) controls the shift lock solenoid by providing battery voltage to the shift lock control solenoid. The BCM utilizes a smart driver to control the voltage supplied to the shift lock solenoid. The smart driver monitors the voltage and current flow of the control circuit.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, vehicle in PARK, observe the scan tool TCM TR SW parameter. The parameter should indicate PARK. If not the specified value, refer to «Range Selector Displays Incorrect Range»(/chevrolet/colorado/i-2004-2012/remont/automatic-trans/#how-to-overhaul-the-automatic-transmission-4l60-e4l65-e4l70-e-removal-installation-service-troubleshooting-diagnosis) .
  2. Observe the scan tool TCM Brake Switch parameter while pressing and releasing the brake pedal. The parameter should change between Applied and Released. If the parameter does not change between the specified values, refer to «Stop Lamps Malfunction»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems) .
  1. Ignition OFF, disconnect the harness connector at the shift lock control solenoid.
  2. Ignition OFF, test for less than 1.0 ohm between the ground circuit terminal B and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Install a test lamp between the ground circuit terminal B and the control circuit terminal A.
  4. Ignition ON, command the scan tool BCM Brake to Shift Relay output control ON and OFF. The test lamp should turn ON and OFF as commanded. If the test lamp is always ON, test the control circuit for short to voltage. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the control circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  5. If the circuit tests normal, replace the transmission control.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Automatic Transmission Shift Lock Control Actuator Replacement»(/chevrolet/colorado/i-2004-2012/remont/automatic-trans/#shift-interlock-system)
  2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup and programming

Removal Procedure

  1. Disable the SIR system. Refer to «SIR Disabling and Enabling»(/chevrolet/colorado/i-2004-2012/remont/airbag/#supplemental-inflatable-restraint-system__sir-disabling-and-enabling) .
  2. Remove the steering column trim covers. Refer to «Steering Column Trim Covers Replacement»(/chevrolet/colorado/i-2004-2012/remont/steering-column-switches/#steering-wheel-steering-column) .
  3. Disconnect the automatic transmission shift lock control actuator electrical connector.
  4. Put the shift lever clevis into the neutral position.
  5. Use a small screwdriver to pry the automatic transmission shift lock control actuator away from the steering column jacket and the cable shift cam assembly.
  6. Remove the automatic transmission shift lock control actuator.

Installation Procedure

  1. Firmly install the automatic transmission shift lock control actuator onto the steering column jacket and the cable shift cam assembly.
  2. Connect the automatic transmission shift lock control actuator electrical connector.
  3. Adjust the automatic transmission shift lock control actuator (with the shift lever clevis in the neutral position) in the following way: Pull out the tab (1) on the adjuster block side (2) of the automatic transmission shift lock control actuator. Press on the adjuster block (2) to compress the internal adjuster spring which disengages the adjuster teeth. Slide the adjuster block (2) as far away from the actuator as possible. Lock the adjuster block (2) in place by pushing in on the tab (1).
  4. Inspect the automatic transmission shift lock control actuator for the following items: The automatic transmission shift lock control actuator must lock the shift lever clevis when the shift lever clevis is put into the park position. Turn the ignition to the ON position and depress the brake pedal to move the shift lever out of the park position. The actuator will be energized. Readjust the automatic transmission shift lock control actuator if needed.
  5. Install the steering column trim covers. Refer to «Steering Column Trim Covers Replacement»(/chevrolet/colorado/i-2004-2012/remont/steering-column-switches/#steering-wheel-steering-column) .
  6. Enable the SIR system. Refer to «SIR Disabling and Enabling»(/chevrolet/colorado/i-2004-2012/remont/airbag/#supplemental-inflatable-restraint-system__sir-disabling-and-enabling) .

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 engine control module (ECM)
  4. The transmission control module (TCM)

The body control module (BCM) controls the voltage supply circuit of the shift lock control solenoid. The following conditions must be met before the BCM will supply battery voltage to the shift lock control solenoid

  1. The ignition is in the ON position.
  2. The ECM sends a serial data message to the BCM indicating the transmission is in the PARK position.
  3. The ECM receives a brake applied input from the brake light switch and sends a serial data message to the BCM indicating the brakes are not applied.

With the above conditions met, the BCM supplies battery voltage to the shift lock control solenoid. The solenoid is permanently grounded and therefore energizes, locking the shift lever in the PARK position. When the brake pedal is depressed the ECM send a serial data message to the BCM indicating the brakes are applied. The BCM turns off the battery voltage supply to the shift lock control solenoid. This de-energizes the shift lock control solenoid releasing the mechanical lock, allowing the driver to move the shift lever out of the PARK position. With the shift lever out of the PARK position the ECM sends a serial data message to the BCM and no voltage is applied to the shift lock control solenoid.

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