Pinpoint Test F: Incorrect Speedometer Indication
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test F: Incorrect Speedometer Indication
Normal Operation
The Instrument Panel Cluster (IPC) receives the Vehicle Speed Sensor (VSS) signal from the PCM over the High Speed Controller Area Network (HS-CAN) communication bus. The PCM receives the VSS input from the Output Shaft Speed (OSS). The IPC monitors the VSS input from the PCM and commands the speedometer with a corresponding movement of the pointer.
Factors that could potentially affect the accuracy of the speedometer are tire wear and configurable items such as tire size configuration and axle ratio configuration.
If the vehicle speed data is missing or invalid for 5 seconds or less, the IPC defaults the speedometer to the last setting, based upon the last known good vehicle speed message received.
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 is missing or invalid for 5 seconds or more, the IPC sets DTC U0401:00 and defaults the speedometer to 0 km/h (0 mph).
NOTE: If DTC U0100:00 is set in the IPC, other observable symptoms may be an inoperative tachometer, temperature gauge or odometer.
This pinpoint test is intended to diagnose the following:
- Axle ratio configuration
- Tire size configuration
- PCM
- IPC
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 tire size is correctly configured.
- Is 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 for recorded PCM DTCs from the Key ON Engine OFF (KOEO) self-test.
- Are any PCM DTCs recorded?
Yes
DIAGNOSE all PCM DTCs first. REFER to Computers and Control Systems Information.
No
GO to F3.
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F3 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST
- Check for recorded DTCs from the IPC self-test.
- Are any DTCs recorded?
Yes
For DTC U0100:00, Go To Pinpoint Test AT. Pinpoint Tests AT: DTC U0100:00
For all other DTCs, REFER to DTC Charts. Instrumentation, Message Center and Warning Chimes
No
GO to F4.
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F4 OBSERVE THE SPEEDOMETER OPERATION
- Ignition ON.
- Observe the speedometer while driving the vehicle at various speeds and stopping frequently.
- Does the speedometer begin at 0 km/h (0 mph) and fully return to the 0 km/h (0 mph) position when the vehicle is stopped?
Yes
GO to F5.
No
INSTALL a new IPC. REFER to Instrument Panel Cluster (IPC) Instrument Panel Cluster (IPC). TEST the system for normal operation.
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F5 CARRY OUT THE IPC 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 and command the speedometer in increments of approximately 10%. Observe the speedometer. The speedometer starts at 0 km/h (0 mph) and moves approximately 16 km/h (10 mph) for each 10% increment.
- Does the speedometer begin at 0 km/h (0 mph) and move by approximately 16 km/h (10 mph) for each 10% increment?
Yes
GO to F6.
No
INSTALL a new IPC. REFER to Instrument Panel Cluster (IPC) Instrument Panel Cluster (IPC). TEST the system for normal operation.
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F6 CHECK THE PCM VSS PIDs
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Select the PCM vehicle speed sensor (VSS) PID and monitor the PID while driving the vehicle at 32 km/h (20 mph), 64 km/h (40 mph) and 97 km/h (60 mph).
- Does the speedometer indicate between 31-34 km/h (19-21 mph), 63-69 km/h (39-43 mph) and 93-103 km/h (58-64 mph) at the 3 PCM PID values?
Yes
INSTALL a new PCM. TEST the system for normal operation.
No
INSTALL a new IPC. REFER to Instrument Panel Cluster (IPC) Instrument Panel Cluster (IPC). TEST the system for normal operation.
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