Normal Operation

The instrument cluster receives the vehicle speed sensor (VSS) status from the powertrain control module (PCM) over the high speed controller area network (HS-CAN) bus lines. The PCM receives the VSS status from the output shaft speed (OSS) sensor. The instrument cluster upon receipt of the VSS data commands the speedometer to sweep to the correct position. The instrument cluster sets DTC U0100 in continuous memory if the VSS data is not received for more than 5 seconds and 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
instrument cluster

SPEEDOMETER INOPERATIVE/INACCURATE PINPOINT TEST 4

PINPOINT TEST 4		THE SPEEDOMETER IS INOPERATIVE/INACCURATE
STEP	INSPECTION		ACTION
1	RETRIEVE THE RECORDED DTCs FROM BOTH THE CONTINUOUS AND ON-DEMAND PCM SELF-TESTS Retrieve the recorded DTCs from the PCM continuous and on-demand self-tests. Are any DTCs retrieved?	Yes	See DIAGNOSTIC TROUBLE CODE (DTC) INDEX - POWERTRAIN CONTROL MODULE (PCM) .
1		No	Go to next step.
2	RETRIEVE THE RECORDED DTCs FROM BOTH THE CONTINUOUS AND ON-DEMAND INSTRUMENT CLUSTER SELF-TESTS Retrieve the recorded DTCs from the instrument cluster continuous and on-demand self-tests. Is DTC U0100 retrieved?	Yes	CLEAR the DTCs. CYCLE the key and wait 10 seconds. REPEAT the self-test. If DTC U0100 is retrieved again, go to step 6.
2		No	Go to next step.
3	CHECK FOR CORRECT AXLE RATIO AND TIRE SIZE CONFIGURATION Key in OFF position. Enter the following diagnostic mode on the scan tool: Module Programming Select programmable parameters and confirm that the axle ratio and the tire size is correctly configured. Is the axle ratio and tire size correctly configured?	Yes	Go to next step.
3		No	CONFIGURE the axle ratio or tire size as required. TEST the system for normal operation.
4	MONITOR PCM VEHICLE SPEED SIGNAL (VSS) PIDs Enter the following diagnostic mode on the diagnostic 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	Go to step 6.
4		No	Go to next step.
5	CARRY OUT THE INSTRUMENT CLUSTER GAUGES ACTIVE COMMAND USING THE SCAN TOOL Key ON engine OFF (KOEO). Enter the following diagnostic mode on the scan tool: Instrument Cluster DataLogger Select the instrument cluster gauges 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	Go to next step.
5		No	Go to step 7.
6	CHECK FOR CORRECT PCM OPERATION Disconnect all the PCM connectors. Check for: corrosion damaged pins pushed-out pins Connect the all the PCM connector and make sure they seat correctly. Operate the system and verify the concern is still present. Is the concern still present?	Yes	INSTALL a new PCM. See POWERTRAIN CONTROL MODULE (PCM) REMOVAL / INSTALLATION . TEST the system for normal operation.
6		No	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
7	CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION Disconnect all instrument cluster connectors. Check for: corrosion damaged pins pushed-out pins Connect all instrument cluster connectors and make sure they seat correctly. Operate the system and verify the concern is still present. Is the concern still present?	Yes	INSTALL a new instrument cluster. See INSTRUMENT CLUSTER . TEST the system for normal operation.
7		No	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.