Diesel Data: Automotive Repair

Pinpoint Test E: The Speedometer Is Inoperative




Instrumentation, Message Center and Warning Chimes

Pinpoint Test E: The Speedometer Is Inoperative

Normal Operation

The Instrument Panel Cluster (IPC) receives the vehicle speed signal from the PCM over the High Speed Controller Area Network (HS-CAN) communication bus. The vehicle speed data originates with the wheel speed sensors. The ABS module provides the wheel speed data to the PCM over the HS-CAN communication bus. The IPC monitors the vehicle speed input from the PCM and commands the speedometer with a corresponding movement of the pointer.

If the IPC receives invalid vehicle speed data from the PCM for 5 seconds or less, the IPC defaults the speedometer to the last setting, based upon the last known good vehicle speed message. If the IPC does not receive the vehicle speed data from the PCM for more than 5 seconds, the IPC sets DTC U0100:00 in continuous memory and defaults the speedometer to 0 km/h (0 mph). If the vehicle speed data received is deemed invalid by the IPC, the IPC sets DTC U0401:68 and defaults the speedometer to 0 km/h (0 mph).

NOTE: If DTC U0100:00 sets in the IPC, other observable symptoms may be an inoperative tachometer or odometer.

This pinpoint test is intended to diagnose the following:

- PCM
- IPC

PINPOINT TEST E: THE SPEEDOMETER IS INOPERATIVE

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E1 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO SELF-TEST

- Check the recorded PCM DTCs from the Key ON Engine OFF (KOEO) self-test.
- Are any DTCs recorded?

Yes
REFER to Computers and Control Systems. TEST the system for normal operation.

No
GO to E2.

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E2 CARRY OUT THE SPEEDOMETER ACTIVE COMMAND USING THE SCAN TOOL

- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IPC DataLogger.
- Select the IPC speedometer (SPDOMETER) active command. Command the speedometer on and off while monitoring the speedometer.
- Does the speed begin at 0 km/h (0 mph) move to 209 km/h (130 mph) and return to 0 km/h (0 mph)?

Yes
GO to E3.

No
INSTALL a new IPC. REFER to Instrument Panel Cluster (IPC) Service and Repair. TEST the system for normal operation.

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E3 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST

- Check for recorded IPC DTCs from the self-test.
- Are any DTCs recorded?

Yes
For DTC U0100:00, GO to Pinpoint Test AM. For all other DTCs, REFER to DTC Charts. Pinpoint Tests AM: DTC U0100:00 and P1607:87

No
INSTALL a new PCM. REFER to Electronic Engine Controls Service and Repair. TEST the system for normal operation.

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