just check whats my trouble code and it is trouble code 12 and 51 ? i have 89 camaro rs 5.0 tbi with k&n air filter and 2.5 in exhuast with flowmaster last owner had removed the cataylitic converter car runs fine idle is around 2500 i belive i drove 100 plus miles the other day only isssue is it runs 250 for coolant temp i just got 160 thermastat new coolant temp sensor and about to flush fluid with water then put in 50/50 mix as got airdam and chin spolier off 90 camaro i know its either the prom or ecu but not sure where to start to troubleshoot

 

thanks

 

Code 12 is normal and expected. Code 51 is a bad PROM. If you ran the engine with the PROM removed code 51 will be set.

At key-on, engine-off look for the SES blink.

The SES should light up, blink off, then light up solid. If it does that you are good to go.

Note that the fan is not under ECM control. It is controlled by the head switch between 6 & 8, and the A/C system.

There are three coolant temperature sensors/switches. One for the dash gauge/light, one for the cooling fan, and one for the ECM.

RBob.

 

oh ok i think it just constantly blinks on key on engine off ill double check if "SES should light up, blink off, then light up solid" what sensor is by the themastat neck on top of the intake manifold i compared it to the new sensor and looks alike ill look for the sensor by the head to

thanks alot RBob

 

If the SES is flashing that means: either, the PROM is bad, the PROM is missing, the PROM is not for that ECM, or the ECM is bad.

If the sensor has two wires, a yellow and a black, that is the coolant temperature sensor (CTS) for the ECM.

RBob.

 

OK im going to check that out then

 

coolant temp.

 

around 250

 

coolant temp...

 

oh ok lol