Contents Wiring diagrams Section: Automatic Trans All sections

Shift Interlock System: Diagnosis Cadillac STS I

Automatic Trans ~512 words

Diagnostic Starting Point - Automatic Transmission Shift Lock Control

Begin the system diagnosis with Diagnostic System Check - Vehicle in Vehicle DTC Information. The Diagnostic System Check - Vehicle 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 - Vehicle will identify the correct procedure for diagnosing the system and where the procedure is located.

Scan Tool Output Controls

Scan Tool Output ControlAdditional Menu Selection(s)Description
Shift Lock Solenoid ControlSpecial Functions-Output ControlRCDLR controls the ground of the shift lock solenoid circuit, ground to the circuit will UNLOCK the gear shift lever.

Remote Control Door Lock Receiver (RCDLR)

Scan Tool Data List

Scan Tool ParameterData ListUnits DisplayedTypical Data Value
Operating Conditions: Ignition ON, with the engine OFF. Transmission shift lever in the PARK position, Brake pedal released.
Battery VoltageData0-15 volts12.5 volts
Ignition 1InputsON/OFFON
Shift Lock Solenoid CommandDataUNLOCK/LOCKLOCK
Shift Lock Solenoid StateDataUNLOCK/LOCKLOCK

Remote Control Door Lock Receiver (RCDLR) Data List

Scan Tool ParameterData ListUnits DisplayedTypical Data Value
Operating Conditions: Ignition ON, with the engine OFF. Transmission shift lever in the PARK position.
TR Sw. A/B/C/PTransmission DataPark, Park/Reverse, Reverse, Reverse/Neutral, Neutral, Neutral/Drive 4, Drive 4, Drive 4/Drive 3, Drive 3, Drive 3/Drive 2, Drive 2, Drive 2/Drive 1, Drive 1, Invalid, Open
TCC Brake SwitchTransmission DataON/OFFOFF

Transmission Control Module (TCM) Data List

Circuit Description

The remote control door lock receiver (RCDLR) controls the automatic transmission shift lock control solenoid by providing a ground for the solenoid. The RCDLR utilizes a smart driver to control the ground to the automatic transmission shift lock control solenoid. The smart driver monitors the voltage and current flow of the control circuit.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC B2710 Gearshift Lock Circuit

Conditions for Running the DTC

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

Conditions for Setting the DTC

  1. DTC B2710-02 Gearshift Lock Circuit Short to Ground. The RCDLR will set the code if the voltage level at the shift lock control output is less than 2.0 volts for more than 0.375 seconds while the output is inactive.
  2. DTC B2710-01 Gearshift Lock Circuit Short to Battery. The voltage level at the shift lock control output is greater than 8.0 volts for more than 0.375 seconds while the output is active.

Action Taken When the DTC Sets

The RCDLR will not attempt to ground the control circuit of the automatic transmission shift lock control solenoid until the next key cycle.

Conditions for Clearing the DTC

  1. A current DTC B2710 will clear when the malfunction is no longer present and the ignition switch is cycled.
  2. All RCDLR history codes will clear after 100 ignition cycles with no current codes active during the 100 ignition cycles.

Diagnostic Aids

  1. If the automatic transmission shift lock control circuit is shorted to ground, the automatic transmission shift lock control solenoid will be inoperative. The vehicle will shift out of PARK without depressing the brake pedal.
  2. Perform the tests while wiggling the wires and connectors. This may often cause an intermittent malfunction to appear. Refer to «Testing for Intermittent Conditions and Poor Connections»(ref-197533-S35858719362005101200000) in Wiring Systems.

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»(ref-197533-S03944243902005101200000) in Wiring Systems.
  2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Symptom List

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

  1. «Shift Lever Does Not Move with Brake Pedal Depressed»(ref-197594-S04934757622005101200000)
  2. «Shift Lever Can Be Moved without Brake Pedal Depressed»(ref-197594-S02638087822005101200000)