Check Code 12

WARNING: This page is about a different car, the 2007 Mazda MX-5 Miata. However, it is still accessible from the selected car via links, so may be relevant.

CHECK CODE 12

Check code 12	Speedometer display signal
INSPECTION CONDITION	DISPLAY	ACTION
After selecting check code 12, wait for approx. 2 s.	Courtesy of MAZDA MOTORS CORP.	The speedometer needle moves full scale then returns to approx. 60 km/h or approx. 60 mph.	The speedometer is normal.
	Courtesy of MAZDA MOTORS CORP.	Except above	Replace the instrument cluster.
	Courtesy of MAZDA MOTORS CORP.	-	Replace the instrument cluster.