Pinpoint Test D: The Speedometer Is Inoperative/Inaccurate

Instrumentation and Warning Chimes

Pinpoint Tests

Pinpoint Test D: The Speedometer Is Inoperative/Inaccurate

Normal Operation

The Instrument Cluster (IC) receives the vehicle speed data from the PCM over the High Speed Controller Area Network (HS-CAN) bus lines. The PCM receives the vehicle speed data from the Output Shaft Speed (OSS) sensor. The IC, upon receipt of the Vehicle Speed Sensor (VSS) data commands the speedometer to sweep to the correct position. The IC sets DTC U0100 in continuous memory if the VSS data is not received for more than 5 seconds and the speedometer does not operate, indicating 0 MPH. If VSS data is missing or invalid for less than 5 seconds, the speedometer stops registering vehicle speed changes and freezes at the last position on the gauge.

This pinpoint test is intended to diagnose the following:

- Vehicle configuration
- PCM
- IC



PINPOINT TEST D: THE SPEEDOMETER IS INOPERATIVE/INACCURATE

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D1 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO SELF-TEST


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

Yes
REFER to the Computers and Control Systems Information.

No
GO to D2.

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D2 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST


- Retrieve the recorded DTCs from the IC self-test.
- Is DTC U0100 retrieved?

Yes
Go To Pinpoint Test AK. Pinpoint Tests AK: DTC U0100

No
GO to D3.

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D3 CHECK FOR CORRECT AXLE RATIO AND TIRE SIZE CONFIGURATION


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Module Programming.
- Select programmable parameters and confirm that the axle ratio and the tire size are correctly configured.
- Is the axle ratio and tire size correctly configured?

Yes
GO to D4.

No
CONFIGURE the axle ratio or tire size as required. TEST the system for normal operation.

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D4 MONITOR PCM VSS PIDs


NOTE: This step may require the assistance of a second person to monitor and record the scan tool data.

- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Select, monitor and record the PCM PID (VSS) while driving at various different speeds.
- Compare the VSS PID values with the speedometer reading.
- Do the values on the speedometer match the PCM PID values?

Yes
INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). TEST the system for normal operation.

No
GO to D5.

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D5 CARRY OUT THE IC GAUGES ACTIVE COMMAND USING THE SCAN TOOL


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IC DataLogger.
- Select the IC speedometer (SPDOMETER) active command. Select and scroll the speedometer 20%, 50% and 70%.
- Does the speedometer indicate approximately 24 mph at 20%, 60 mph at 50% and 84 mph at 70%?

Yes
INSTALL a new PCM. TEST the system for normal operation.

No
INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). TEST the system for normal operation.

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