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 Descriptors

DTC P0706: Transmission Range (TR) Switch Performance

DTC P0707: Transmission Range (TR) Switch Circuit Low Voltage

DTC P0708: Transmission Range (TR) Switch Circuit High Voltage

Circuit/System Description

The transmission range (TR) switch is an integral part of the transmission control module (TCM). The TR switch input/output circuitry consists supply voltage (Vcc), ground (GND), position signal 1 (Pos1), and position signal 2 (Pos2). Each gear range position (P, R, N, D, 4, 3, and 2) corresponds to a particular voltage (1-5 volts) within the TCM.

Conditions for Running the DTC

P0706

    • The ignition is ON, or the engine is operating.
    • The transmission is not in Service Mode.
    • There is not a Transmission Range Switch Circuit Low Voltage DTC, P0707.

P0707 and P0708

    • The ignition is ON, or the engine is operating.
    • The transmission is not in Service Mode.

Conditions for Setting the DTC

P0706

The TCM detects that the TR switch position sensor is stuck for 0.5 second.

P0707

The TCM detects that the TR switch position sensor circuit is open or shorted to ground for 0.5 second.

P0708

The TCM detects that the TR switch position sensor circuit is shorted to voltage for 0.5 second.

Action Taken When the DTC Sets

    • DTC P0706, DTC P0707, and DTC P0708 are Type A DTCs.
    • The TCM will use the previous range information.
    • The transmission will operate in 5th gear only in D or M range.
    • The TCM inhibits 1st gear.
    • The TCM inhibits engine start.
    • The TCM inhibits Self-learning

Conditions for Clearing the DTC

DTC P0706, DTC P0707, and DTC P0708 are Type A DTC’s

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

    •  Automatic Transmission Inline Harness Connector End View
    •  Automatic Transmission Internal Connector End Views
    •  Automatic Transmission Related Connector End Views

Electrical Information Reference

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

DTC Type Reference

    •  Diagnostic Trouble Code (DTC) Type Definitions
    •  Diagnostic Trouble Code (DTC) List/Type

Circuit/System Verification

  1. Ignition ON, observe the DTC information with a scan tool.
  2. Record Freeze Frame and Failure Records.
  3. Clear DTCs.
  4. Operate the vehicle under the conditions observed in the Failure Records.
  5. Observe the DTC information with the scan tool. Verify that DTC P0706, P0707, or P0707, or P0708 does not set.
  6. If specified DTC sets, replace the TCM, refer to Transmission Control Module Removal procedure and Transmission Control Module Installation procedure.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.