Test M: O/D Off Indicator Inoperative/Always On

NOTE: Perform all voltage and resistance tests using a Digital Volt-Ohm Meter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter to isolate wiring harness shorts or opens.

Turn ignition switch to RUN position. If O/D OFF indicator is always illuminated, go to next step. If O/D OFF indicator is not always illuminated, go to step 3.
Turn ignition switch to LOCK position. Disconnect 12-pin instrument cluster harness connector C220a. See Figure. It may be necessary to remove instrument cluster for access to connector. See INSTRUMENT CLUSTER MODULE under REMOVAL & INSTALLATION. Turn ignition switch to RUN position. If O/D OFF indicator is not illuminated, repair transmission control switch circuit. See SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV article in ENGINE PERFORMANCE. After repair, test system for normal operation. If O/D OFF indicator is illuminated, go to step 4.
Perform INSTRUMENT CLUSTER MODULE SELF-TEST under SELF-DIAGNOSTIC SYSTEM. If O/D OFF indicator operated properly during "bulb" portion of test, repair transmission control switch circuit. See SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV article in ENGINE PERFORMANCE. After repair, test system for normal operation. If O/D OFF indicator did not operate properly during "bulb" portion of test, go to next step.
Disconnect all instrument cluster harness connectors. It may be necessary to remove instrument cluster for access to instrument cluster harness connectors. See INSTRUMENT CLUSTER MODULE under REMOVAL & INSTALLATION. Inspect all instrument cluster harness connectors for loose, damaged or corroded terminals. If terminals are damaged, repair or replace as necessary. If terminals are not damaged, reconnect all instrument cluster harness connectors. Ensure instrument cluster harness connectors are seated properly. If problem still exists, replace instrument cluster module. After repair, clear DTCs, repeat self-test and check system for normal operation.