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Shift Interlock System Cadillac CTS II

Automatic Trans 1 illustration ~1413 words

Scheme 32

Scheme 32: Shift Lock Control Schematics
Scheme 32: Shift Lock Control Schematics

DIAGNOSTIC CODE INDEX

DTCDescription
DTC B2705B2705 02: Gearshift Unlock Circuit Short to Ground

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__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 Ground1
Shift Lock Control Solenoid ControlB2705 0212
1. Shift lever will not move from PARK with the brake pedal pressed. 2. Shift lever will move from PARK without pressing on the brake pedal.

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

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 will clear when the malfunction is no longer present and the ignition switch is cycled.
  2. All BCM history codes will clear after 100 ignition cycles with no current codes active during the 100 ignition cycles.

Reference Information

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Ignition ON, Clear the DTC. Observe the scan tool BCM Brake Applied Output Signal parameter. The parameter should change from ON to OFF when the brake pedal is depressed and released. If the parameter does not change, refer to «Stop Lamps Malfunction»(/cadillac/cts/ii-2007-2014/remont/exterior-lights/#lighting-system) .
  2. Press the brake pedal, the vehicle operator should not be able to move the shifter lever out of the PARK position.

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 ohms 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 BCM scan tool Shift Lock Solenoid 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, test or replace the shift lock control solenoid.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Transmission Control Replacement»(/cadillac/cts/ii-2007-2014/remont/automatic-trans/#automatic-transmission-6l456l506l806l90-repair-instructions-on-vehicle)
  2. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup, and programming

Symptoms - Automatic Transmission Shift Lock Control

IMPORTANTThe following steps must be completed before using the symptom tables.
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) before using the Symptom Tables in order to verify that all of the following are true: There are no DTCs set. The control modules 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»(/cadillac/cts/ii-2007-2014/remont/automatic-trans/#shift-interlock-system__automatic-transmission-shift-lock-control-description) .

Visual/Physical Inspection

  1. Inspect for aftermarket devices which could affect the operation of the automatic transmission shift lock control. Refer to «Checking Aftermarket Accessories»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__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 in order to diagnose the symptom

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Shift Lock Control Solenoid Ground1
Shift Lock Control Solenoid VoltageB2705 0212
1. Shift lever will not move from PARK with the brake pedal pressed. 2. Shift lever will move from PARK without pressing on the brake pedal.

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»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, with the brake pedal applied, observe the scan tool Brake Applied Output Signal parameter. The reading should be ON with the brake pedal depressed and released. If not the specified parameter, refer to «Stop Lamps Malfunction»(/cadillac/cts/ii-2007-2014/remont/exterior-lights/#lighting-system) .
  2. Press the brake pedal, the vehicle operator should be able to move the shifter lever out of the PARK position.
  1. Ignition OFF, disconnect the harness connector at the automatic transmission shift lock actuator.
  2. Test for less than 1.0 ohms between the ground circuit terminal K and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Connect a test lamp between the control circuit terminal E and ground.
  4. Ignition ON, command the scan tool BCM shift lock solenoid 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 a short to voltage. If circuit test normal, replace the BCM. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If circuits test normal, replace the BCM.
  5. If all circuits test normal, test or replace the shift lock actuator.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Transmission Control Replacement»(/cadillac/cts/ii-2007-2014/remont/automatic-trans/#automatic-transmission-6l456l506l806l90-repair-instructions-on-vehicle)
  2. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup and programming

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 the following components

  1. The automatic transmission shift lock solenoid (serviced as the automatic transmission shift lock actuator), as well as the body control module (BCM) and the engine control module (ECM). The shift lock solenoid is located within the floor shift control assembly with vehicles equipped with floor shift.
  2. The body control module (BCM) controls the voltage supply circuit of the shift lock control solenoid. The following conditions must be before the BCM will supply voltage to the shift lock control solenoid.

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 solenoid

  1. The ignition is in the ON position.
  2. The engine control module (ECM) sends an input via GMLAN serial data to the BCM indicating the transmission is in the PARK position.
  3. The BCM determines the brake pedal is applied according the brake pedal position.

Since the shift lock control solenoid is permanently grounded, the BCM supplies voltage to the automatic transmission shift lock control solenoid, mechanically unlocking the shift lever allowing the driver to move the shift lever out of the PARK position as the solenoid energizes. When the brake pedal is not applied, the BCM turns the control voltage output 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.

During remote start operation, the BCM will de-energize the shift lock control circuit, locking the shift lever in the PARK position.

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