Hi guys,
not really sure what the issue is. It started happening after I changed the radiator to a brand new one (may or may not be related).
Usually about ten minutes into a drive the orange light (the light that stays on when you have a bad Main fuel relay) comes on whilst driving. Performance doesn’t seem to be affected at all. Does any one know what could be the cause of this. I’ve never heard of it happening before.
Any help or ideas would be super appreciated. Have tried resetting the ecu… no change.
Check the CEL code.
it doesn’t throw any codes. the cel light stays on constant with the paperclip in the service port.
it is the check engine light that is illuminated, yes?
if it’s a 90-91, you don’t jmp the service connector to retrieve codes. the ecm, under the passanger footwell carpet will have an led on it. with the key on, the led will flash you the code.
it’s a 92-93, sorry I should have stated.
i believe a solid cel is an ecm issue.
so withnthe key on, there is no cel. jump the connector, and cel is solid? that is correct? or is the cel on with the key on and connector not jumped as well?
with the key on there is no cel (there is a cel for 2 seconds that goes away when the mfr clicks), jump the connector and the cel is solid.
ecm? what’s that?
i bought this car second hand and the ecu was chipped by the previous owner. is this possibly why i’m getting a cel and no code? (now i know why you never buy a modded car). Is it possible to remove this chip and put it back to stock? would I need any parts or should I just start shopping for a new ecu? or both.
try the k test:
Remove the MAP Sensor connector and turn the ignition switch to ON (not start). Using a multi-meter, check for 5 volts going between the MAP Sensor connector’s reference wire (+) and ground. As you look at the connector, this is the socket on the right. Really press the black test lead into a cleaned main ECM ground on the thermostat housing. If the voltage is low, it’s probably indicating ECM failure. Most failed ECMs will record a fraction of a volt.
Sounds to me like everything is working as it should! If the CEL goes off after 2 seconds of turning on the car, you have no issues. Which in turn will give you a solid CEL with the jumper in place.
Put the jumper in while the CEL is on during your drive. It sounds like the VSS is not sending a signal to your ECU.
Hi Everyone,
Mystery solved. I don’t want to admit what a noob I was posting before really going over it. The hazard/backup 10amp fuse in the engine bay had blown so it wasn’t remembering the cel code. Who would have thought it could be that simple. Thank you all for your advice. I dare say jumping the service port while the car was running and the cel was lit would have also gotten me the answer I needed.
so what was the code?
code 43, put a new o2 sensor in. I thought the car was running well before, but now it’s running even better.
i guess the ecm KAM power is supplied through the hazard fuse. that’s where your solid cel came from.
glad it’s all sorted