Overdrive Switch
- Check for continuity between switch terminals on overdrive switch harness connector. See WIRING DIAGRAMS . Continuity should exist with switch in OFF position. Continuity should not exist with switch in ON position. Replace switch as necessary.
- Turn ignition switch to ON position. Using voltmeter, backprobe TCM connector. Measure voltage between ground and terminal No. 39. With overdrive switch in ON position, battery voltage should be present. With overdrive switch in OFF position, one volt or less should be present. If voltage is not as specified, repair circuit as necessary.