GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0705: Transmission Range (TR) Switch Circuit

Circuit/System Description

The transmission range (TR) switch is a sliding contact switch. The 4 inputs to the transmission control module (TCM) from the switch indicate which position is selected by the transmission manual shaft. The input voltage at the TCM is low when the switch is open and high when the switch is closed. The state of each input is displayed on the scan tool as Selector Position Switch.

Conditions for Running the DTC

    • The ignition is ON for 2 seconds.
    • The transmission is not in emergency mode.

Conditions for Setting the DTC

The TCM detects that the TR switch indicates an invalid range for 0.5 second.

Action Taken When the DTC Sets

    • DTC P0705 is a Type A DTC.
    • The transmission will operate in 4th gear only in D range.

Conditions for Clearing the DTC

DTC P0705 is a Type A DTC.

Diagnostic Aids

Selector Position Switch table

Range

P

R

N

D

3

2

L

Sw. A

ON

ON

OFF

OFF

ON

ON

OFF

Sw. B

OFF

ON

ON

ON

ON

OFF

OFF

Sw. C

OFF

OFF

OFF

ON

ON

ON

ON

Sw. PA

ON

OFF

ON

OFF

ON

OFF

ON

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Electronic Component Description

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References

Circuit/System Verification

  1. Ignition ON, engine OFF, observe the scan tool Selector Position Switch parameter’s while moving the gear shift lever from Park and through all the ranges. The parameter’s should match each gear range that is selected as shown in the Selector Position Switch table, Diagnostic Aids.
  2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

  1. Disconnect the Selector Position Switch harness at the switch.
  2. Ignition ON, verify the scan tool Selector Position Switch A/B/C/PA parameter displays OFF for all four signal circuits.
  3. If not the specified value, replace the TCM.
  4. Connect a 3-amp fused jumper wire between each transmission range signal circuit terminal listed below and B+. The appropriate scan tool A/B/C/PA parameter should display ON when the terminal is connected to B+.
  5. • Switch Signal A
    • Switch Signal B
    • Switch Signal C
    • Switch Signal PA
    If not the specified value, replace the TCM.
  6. If all circuits test normal, test or replace the Selector Position Switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Control Module References for TCM replacement, setup, and programming
    •  Transmission Range Switch Replacement for Selector Position Switch Replacement