Diagnostic Procedure

WARNING: This page is about a different car, the 2005 Mazda MX-5 Miata. However, it is still accessible from the selected car via links, so may be relevant.

O/D OFF INDICATOR LIGHT ILLUMINATES WHEN O/D OFF SWITCH IS NOT TURNED ON - DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Inspect O/D OFF switch. (See O/D OFF SWITCH INSPECTION . ) Is O/D OFF switch okay?	Yes	Go to next step.
1		No	Replace O/D OFF switch. (See O/D OFF SWITCH REMOVAL/INSTALLATION . )
2	Inspect TCM terminal L voltage. (See TRANSMISSION CONTROL MODULE (TCM) INSPECTION . ) Is terminal voltage okay?	Yes	Inspect for short to ground circuit between O/D OFF switch terminal and TCM terminal K.
2		No	Inspect for short to ground circuit between O/D OFF indicator light on instrument cluster and TCM terminal L including instrument cluster circuit board.
3	Verify test results. If okay, return to diagnostic index to service any additional symptoms. If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace TCM.