Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

CHECK CODE 18 DIAGNOSTIC PROCEDURE

INSPECTION	INDICATION	SITUATION	ACTION
Wait for 2 seconds after selecting check code 18.	on (Turns on and off)	Ignition key illumination turns on and off three times .	Ignition key illumination is okay.
Wait for 2 seconds after selecting check code 18.	on (Turns on and off)	Other than stated above.	Measure voltage at instrument cluster terminal 2C. Is voltage B+ ? If as specified, replace instrument cluster. If not as specified, inspect following parts. Ignition key illumination Wiring harness (Battery-ignition key illumination-instrument cluster)