Normal Operation

The overdrive (O/D) off function is controlled by the O/D off switch located on the shifter assembly. When the transmission control switch is placed in the O/D OFF position, the O/D off switch provides voltage to the powertrain control module (PCM). The PCM provides the overdrive off status to the instrument cluster over the high speed controller area network (HS-CAN) communication bus. When the overdrive is turned off, the PCM sends a message to the instrument cluster to turn on the O/D off indicator. If an O/D fault condition is detected, the PCM sends a message to the instrument cluster to flash the O/D off indicator. If the O/D status message is missing for more than 5 seconds, the instrument cluster illuminates the O/D off indicator. The instrument cluster sets DTC U0100 in continuous memory if the PCM data is missing for more than 5 seconds or if invalid data is received and the instrument cluster illuminates the O/D off indicator.

This pinpoint test is intended to diagnose the following:

Instrument cluster
PCM

OVERDRIVE OFF INDICATOR PINPOINT TEST 14

PINPOINT TEST 14		THE OVERDRIVE (O/D) OFF INDICATOR IS NEVER/ALWAYS ON
STEP	INSPECTION		ACTION
1	CHECK THE OVERDRIVE OPERATION Test drive the vehicle and check the operation of the transmission control switch. Does the transmission control switch operate correctly?	Yes	Go to next step.
1		No	See AUTOMATIC TRANSMISSION EXTERNAL CONTROLS DIAGNOSIS to continue diagnosis of the transmission control switch.
2	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) .
2		No	Go to next step.
3	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. lfDTCU0100 is retrieved again, go to step 5.
3		No	Go to next step.
4	CARRY OUT THE INSTRUMENT CLUSTER INDICATOR LAMP CONTROL ACTIVE COMMAND USING THE SCAN TOOL Key in ON position. Enter the following diagnostic mode on the scan tool: Instrument Cluster DataLogger Select the instrument cluster O/D off indicator (O_DOFFLMP) active command. Command the O/D off indicator active command on then off again. Observe the overdrive off warning indicator. Does the overdrive off warning indicator illuminate when commanded on and turn off when commanded off?	Yes	Go to next step.
4		No	Go to step 6.
5	CHECK FOR CORRECT PCM OPERATION Disconnect the PCM connector. Check for: corrosion damaged pins pushed-out pins Connect the PCM connector and make sure it seats 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.
5		No	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
6	CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION Disconnect all the instrument cluster connectors. Check for: corrosion damaged pins pushed-out pins Connect all the 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.
6		No	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.