Possible Causes

Instrument cluster
PCM

O/D OFF INDICATOR IS NEVER/ALWAYS ON - PINPOINT TEST REFERENCE

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 U0294 retrieved?	Yes	Clear the DTCs. Repeat the self-test. If DTC U0294 is retrieved again, go to step 5. For all other instrument cluster DTCs, See INSTRUMENT CLUSTER DIAGNOSTIC TROUBLE CODE (DTC) INDEX , .
3		No	Go to next step.
4	CARRY OUT THE INSTRUMENT CLUSTER INDICATOR LAMP CONTROL ACTIVE COMMAND USING THE SCAN TOOL Key ON engine OFF (KOEO). Enter the following diagnostic mode on the scan tool: Instrument Cluster Active Command. Select the instrument cluster indicator lamp active command. Select the overdrive off indicator active command on then off again. Observe the overdrive off indicator. Does the overdrive 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.