Contents Wiring diagrams Section: Automatic Trans All sections

Shift Interlock System: Diagnosis Pontiac GTO IV

Automatic Trans ~469 words

Diagnostic Starting Point - Automatic Transmission Shift Lock Control

Begin the system diagnosis by reviewing the Automatic Transmission Shift Lock Control Description and Operation . Reviewing the Description and Operation information will help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the Description and Operation will also help you determine if the condition described by the customer is normal operation.

Refer to Symptoms - Automatic Transmission Shift Lock Control in order to identify the correct procedure for diagnosing the system and where the procedure is located.

Scan Tool Data List

The Shift lock Control Scan Tool Data List contains all shift lock control related parameters that are available on the scan tool. The list is arranged in alphabetical order. A given parameter may appear in any one of the data lists, and in some cases may appear more than once, or in more than one data list in order to group certain related parameters together.

Use the Shiftlock Control Scan Tool Data List only after the following is determined

  1. The Diagnostic System Check - Vehicle is completed.
  2. No diagnostic trouble codes (DTCs)
  3. On-board diagnostics are functioning properly.

Scan tool values from a properly functioning system may be used for comparison with the system you are diagnosing. The Shiftlock Control Scan Tool Data List represents values that would be seen on a normal functioning system engine.

IMPORTANTA scan tool that displays faulty data should not be used. The scan tool problem should be reported to the manufacturer. Use of a faulty scan tool can result in misdiagnosis and unnecessary parts replacement.

Only the parameters listed below are referenced in this service information for use in diagnosis. If all values are within the typical range described below, refer to Symptoms - Automatic Transmission Shift Lock Control for diagnosis.

The column labeled Data List indicates where a parameter can be located on the scan tool. Refer to the scan tool operating manual for the exact locations of the data lists. The following is a description of each term listed

Scan Tool ParameterData ListParameter Range/UnitsTypical Data Values
Engine Idling/Radiator Hose Hot/Closed Throttle/Park or Neutral/Closed Loop/Accessories Off
BPP SignalElectrical/Theft, Cruise/Traction, Eng, TACApplied/Released/InvalidReleased
BPP Circuit SignalElectrical/Theft, TACApplied/ReleasedReleased
Current GearIPCTransmission Gear Position1,2,3,4,5,6
Ext Travel BPP SignalTACApplied/Released/InvalidReleased
PNP Switch (If Equipped)Electrical/TheftPark, Reverse, Neutral, Drive, 4, 3, 2, 1Park
TCC/Cruise Brake Pedal SwitchMT, TACApplied/ReleasedRelease
TR SwEngTransmission Gear PositionVaries

Scan Tool Data List

Scan Tool Data Definitions

The Shift Lock Control Scan Tool Data Definitions contains a brief description of all engine related parameters available on the scan tool. The list is in alphabetical order. A given parameter may appear in any one of the data lists. In some cases, the parameter may appear more than once or in more than one data list in order to group certain related parameters together.

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 effect the operation of the automatic transmission shift lock control system, Refer to «Checking Aftermarket Accessories»(ref-201038-S27088131452005102400000) in Wiring Systems.
  2. Inspect the easily accessible to visible system components for obvious damage or conditions which could cause the symptom.

Symptom List

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

  1. «Shift Lever Does Not Move with Brake Pedal Depressed»(ref-201086-S07147907092005102400000)
  2. «Shift Lever Can Be Moved without Brake Pedal Depressed»(ref-201086-S03348532542005102400000)