Pinpoint Test F: Incorrect Speedometer Indication

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

Pinpoint Test F: Incorrect Speedometer Indication

Normal Operation

The Instrument Cluster (IC) receives the Vehicle Speed Sensor (VSS) signal from the PCM over the High Speed Controller Area Network (HS-CAN). The PCM receives the VSS data from the Output Shaft Speed (OSS) sensor. The IC monitors the VSS input from the PCM module and commands the speedometer with a corresponding movement of the pointer.

This pinpoint test is intended to diagnose the following:

- Incorrect tire size
- Axle ratio
- OSS sensor
- PCM
- IC



PINPOINT TEST F: INCORRECT SPEEDOMETER INDICATION

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F1 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.
- Are the axle ratio and tire size correctly configured?

Yes
GO to F2.

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

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F2 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 Information.

No
GO to F3.

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F3 CARRY OUT THE SPEEDOMETER 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. Command the speedometer in 10% increments while monitoring the speedometer. The speed indicated should increase in increments of approximately 20 km/h (12 mph) for each 10% change.
- Does the speed indicated increase within specifications?

Yes
GO to F4.

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

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F4 MONITOR THE VSS PID


- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Select the PCM PID (VSS). Monitor the vehicle speed PID while driving the vehicle.
- Does the vehicle speed PID match the speedometer reading on the IC?

Yes
INSTALL a new OSS sensor. TEST the system for normal operation.

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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