Test S: O/D Off Light Inoperative
- Turn ignition off. Connect New Generation Star (NGS) tester or equivalent scan tool to Data Link Connector (DLC). Turn ignition on. Access Transmission Control Module (TCM) PIDs. Monitor Overdrive Off Switch (ODS). Depress ODS. If O/D OFF light illuminates and ODS signal is present on NGS tester, replace TCM. See appropriate ELECTRONIC CONTROLS article in TRANSMISSIONS. Retest system. If conditions are not as described, go to next step.
- Turn ignition off. Disconnect TCM. TCM is located in bottom of center console. Remove instrument cluster. See INSTRUMENT CLUSTER in REMOVAL & INSTALLATION. Disconnect instrument cluster connector C266B. Using an ohmmeter, measure resistance of Blue/Orange wire between instrument cluster connector C266B terminal No. 7 and TCM connector C277A terminal No. 13. See Figure and Fig 1
. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Blue/Orange wire. Retest system.
- Measure resistance between ground and TCM connector C277A terminal No. 22 (Green/Orange wire) while depressing O/D OFF switch to ON position. If resistance is less than 5 ohms, replace instrument cluster printed circuit. See PRINTED CIRCUIT under REMOVAL & INSTALLATION. Retest system. If resistance is 5 ohms or more, go to next step.
- Disconnect overdrive off switch connector. Overdrive off switch is located at top of steering column near gear selector. Measure resistance between ground and overdrive off switch connector Black wire. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black wire. Retest system.
- Measure resistance of Green/Orange wire between TCM connector C277A terminal No. 22 and overdrive off switch connector. If resistance is less than 5 ohms, replace overdrive off switch. Retest system. If resistance is 5 ohms or more, repair Green/Orange wire. Retest system.
Courtesy of FORD MOTOR CO.