Engine RPM Indicator Malfunction

Engine RPM Indicator Malfunction

Diagnostic Fault Information

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






Circuit/System Description

The engine RPM indicator are a series of LEDs that are set to illuminate and indicate to the driver when the engine attains a certain engine RPM. The indicators are factory preset to illuminate at a certain engine RPM range. The total engine RPM range available to set is 8500 RPM and there are only three RPM settings available for the vehicle transmission range. The factory RPM presets can be changed to any preferred RPM settings but the factory presets are available at the push of a button. Pushing the reset button reverts the RPM indicator to the factory preset which are always the default settings. The engine RPM indicator uses the engine speed signal circuit from the powertrain control module (PCM) to determine the engine speed. The engine RPM indicator performs a self test by briefly turning the LEDs ON and OFF when the ignition is turned ON. Power is provided the engine RPM indicator via the ignition 1 voltage circuit.

Circuit/System Testing

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

• If greater than 1 ohm, test the ground circuit for an open/high resistance.

3. Ignition ON, verify a test lamp illuminates when connected between the ignition 1 voltage circuit and ground.

• If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PCM.

4. Ignition OFF, connect the harness connector at the engine RPM indicator.
5. Ignition ON, verify that the engine RPM indicator performs a self test by briefly turning the LEDs ON and OFF.

• If the engine RPM indicator does not perform a self test, test the engine speed signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PCM.

6. If all circuits test normal, replace the engine RPM indicator.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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* Control Module References for the PCM replacement, setup, and programming Verification Tests