Pinpoint Test G: The Speedometer Is Inoperative
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test G: The Speedometer Is Inoperative
Normal Operation
The PCM receives the vehicle speed data from the Output Shaft Speed (OSS). The PCM provides the Instrument Cluster (IC) with the vehicle speed signal over the High Speed Controller Area Network (HS-CAN) communication bus.
The vehicle speed is calculated in the PCM from the OSS sensor input and the tire size information programmed into the Vehicle Identification (VID) block at the end of the line production. The IC monitors the vehicle speed input from the PCM and commands the speedometer with a corresponding movement of the pointer.
The IC receives the vehicle speed signal from the PCM over the High Speed Controller Area Network (HS-CAN) communication bus. The IC monitors the vehicle speed input from the PCM and commands the speedometer with a corresponding movement of the pointer.
If the vehicle speed data is missing or invalid for 5 seconds or less, the IC defaults the speedometer to the last setting, based upon the last known good vehicle speed message. If the IC does not receive the vehicle speed data from the PCM for more than 5 seconds, the IC sets DTC U0101 in continuous memory and defaults the speedometer to 0 km/h (0 mph). If the vehicle speed data received is deemed invalid by the IC for 5 seconds or longer, the IC sets DTC U2023 and defaults the speedometer to 0 km/h (0 mph).
NOTE: If DTC U0101 is set in the IC, other observable symptoms may be an inoperative tachometer, temperature gauge or odometer.
This pinpoint test is intended to diagnose the following:
- PCM
- IC
PINPOINT TEST G: THE SPEEDOMETER IS INOPERATIVE
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G1 RETRIEVE THE RECORDED DTCs FROM THE PCM KEY ON ENGINE OFF 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 G2.
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G2 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 19 km/h (12 mph) for each 10% change.
- Does the speed begin at 0 km/h (0 mph) and increase by 19 km/h (12 mph) for each 10% increment?
Yes
GO to G3.
No
INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). TEST the system for normal operation.
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G3 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST
- Check for recorded IC DTCs from the self-test.
- Are any DTCs recorded?
Yes
For DTC U0101, GO to Pinpoint Test AM. Pinpoint Tests AM: DTC U0101
For all other DTCs, REFER to DTC Charts. Instrumentation, Message Center and Warning Chimes
No
GO to G4.
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G4 CHECK THE IC VSS INPUT
- Enter the following diagnostic mode on the scan tool: IC DataLogger.
- Select the IC vehicle speed PID (VSS_IC). Drive the vehicle and monitor the VSS PID.
- Does the PID display a VSS input into the cluster?
Yes
INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). TEST the system for normal operation.
No
INSTALL a new PCM. REFER to Electronic Engine Controls Service and Repair. TEST the system for normal operation.
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