Contents Wiring diagrams Section: Automatic Trans All sections

Shift Interlock System: Overview Cadillac STS I

Automatic Trans 2 illustrations ~408 words

Scheme 49

Scheme 49: Automatic Transmission Shift Lock Control Schematics

Scheme 50

Scheme 50: Automatic Transmission Shift Lock Control Component Views
CalloutComponent Name
1Automatic Transmission Shifter Control
2Tap Up/Tap Down Trans Enable Switch
3Automatic Transmission Shift Control Connector
4A/T Shift Lock Control Solenoid
5Tap Up/Tap Down Switch

Test Description

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

  1. 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.
  2. 3: Tests for voltage at the ignition 1 voltage circuit of the automatic transmission shift lock control solenoid.
  3. 4: Verifies that the RCDLR is providing a ground to the automatic transmission shift lock control solenoid.
  4. 5: Tests if ground is constantly being applied to the automatic transmission shift lock control solenoid.
StepActionYesNo
Schematic Reference: Automatic Transmission Shift Lock Control Schematics Connector End View Reference: Automatic Transmission Shift Lock Control Connector End Views or Keyless Entry Connector End Views in Keyless Entry
1Did you perform A Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the brake to shift output control ON and OFF. Does the automatic transmission shift lock control solenoid turn ON and OFF with each command?Go to Testing for Intermittent Conditions and Poor Connections in Wiring SystemsGo to Step 3
3Turn OFF the ignition. Disconnect the automatic transmission shift lock control solenoid. Connect a test lamp between the shift lock control solenoid voltage supply circuit at the connector of the shift lock control solenoid and a good ground. Turn ON the ignition, with the engine OFF. Does the test lamp illuminate?Go to Step 4Go to Step 10
4Turn OFF the ignition. Connect a test lamp between the shift lock solenoid control voltage supply circuit and the shift lock solenoid control circuit at the connector of the shift lock control solenoid. With a scan tool, command the shift lock control solenoid ON and OFF several times. Does the test lamp turn ON and OFF with each command?Go to Step 8Go to Step 5
5Does the test lamp remain illuminated?Go to Step 6Go to Step 7
6Test the control circuit of the automatic transmission shift lock control solenoid 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 9
7Test the control circuit of the automatic transmission shift lock control solenoid for a short to battery voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 13Go to Step 9
8Inspect for poor connections at the harness connector of the automatic transmission 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
9Inspect for poor connections at the harness connector of the remote control door lock receiver (RCDLR). 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
10Repair the open or short to ground in the automatic transmission shift lock control voltage supply circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 13
11Replace the automatic transmission shift lock control solenoid. Refer Automatic Transmission Shift Lock Actuator Replacement . Did you complete the replacement?Go to Step 12
12Replace the RCDLR. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 12
13Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text. Does the DTC reset?Go to Step 2System OK

DTC B2710

Symptoms - Automatic Transmission Shift Lock Control

IMPORTANTThe following steps must be completed before using the symptom tables.
  1. Perform the «Diagnostic System Check - Vehicle»(ref-197532-S30271296932005101200000) in Vehicle DTC Information 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»(ref-197594-S23493038632005101200000) .

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 control solenoid
  2. The remote control door lock receiver (RCDLR)
  3. The transmission control module (TCM)

With the ignition in the ON position, battery positive voltage is supplied to the automatic transmission shift lock control solenoid located within the shift lever assembly. The automatic transmission shift lock control solenoid receives a ground from the RCDLR. The RCDLR receives input thought data communications from the TCM indicating transmission gear position and brake pedal position. With the shift lever in the PARK position the internal park switch of the shift lever assembly closes allowing current to flow to the RCDLR. When the RCDLR receives a data communication that the brake pedal is depressed and the transmission is in the PARK position the RCDLR supplies a ground the shift lock control solenoid control circuit. This energizes the solenoid and allows the shift lever to be moved out of the PARK position. With the shift lever out of the PARK position the internal park switch in the shift lever assemble opens, this de-energies the shift lock control solenoid.