Shift Indicator Inaccurate or Inoperative

Shift Indicator Inaccurate or Inoperative

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview

Circuit/System Description

The transmission control module (TCM) communicates the park/neutral switch status to the body control module (BCM) via serial data. The BCM uses this data to control the Electronic PRNDL display on the shifter. The BCM controls the LEDs in the PRNDL display through 4 control circuits.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the transmission range indicator.
2. Ignition OFF, test for less than 1.0 ohm of resistance between the ground circuit and ground.

• If greater than 1.0 ohm, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between the parklamp voltage supply circuit and ground.

• If the test lamp does not illuminate, repair the parklamp voltage supply circuit for a short to ground or an open/high resistance.

4. Ignition ON, verify that a test lamp illuminates between the PRNDL/powertrain voltage supply circuit and ground.

• If the test lamp does not illuminate, repair the PRNDL/powertrain voltage supply circuit for a short to ground or an open/high resistance.

5. If all circuits test normal, test or replace the transmission range indicator.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

Automatic Transmission Control Indicator Replacement