ZR-1 Net Registry Forums - View Single Post - Speedometer shows 120-220 mph idle high

tccrab · 03-03-2007

ECM is the box on the drivers side firewall. Right next to the power brake booster.
It dismounts by removing the two bolts on the inside and just pivoting up. The PROM lives inside the ECM underneath a plate on the bottom.

Make sure the key not "on" when messing with the ECM.
Remove the negative battery cable as extra insurance.

TomC
'90ZR1 #792

03-03-2007	#4
tccrab Join Date: Oct 2004 Location: Folsom CA Posts: 1,663	Re: Speedometer shows 120-220 mph idle high ECM is the box on the drivers side firewall. Right next to the power brake booster. It dismounts by removing the two bolts on the inside and just pivoting up. The PROM lives inside the ECM underneath a plate on the bottom. Make sure the key not "on" when messing with the ECM. Remove the negative battery cable as extra insurance. TomC '90ZR1 #792