I have a 90 rs camaro tbi with aod trans and federal emissions it is throwing a code 51. Have tried replacing the ECM after witch my idle air gets no voltage from the ecm this isnt a short in the wiring to the idle air because i am recieving no signal from the ecm. The tps appears to be fine i check this with a meter. What sends the signal to the ecm to contorl idle. The car ran fine before with the code i unpluged the ecm switched proms and now the idle will not come down The car is still showing a code 51 and idles at 2500 rpm. I also need to know what the correct prom or memcal for the car is as i believe the previous owner may have changed it any help would be appreciated as i have messed with this for month with no luck.

 

Welcome to TGO.

For 49 state Federal the correct PROM is AXKT
For the 1 odd-ball state the correct PROM is AXKS

Note that the transmission is a 700R4. The AOD is a Ford transmission.

RBob.

 

Ok thanks. Will a prom out of a firebird work as long as it has the same prom broadcast code? And could the wrong prom cause my ecm not to send voltage out of the ecm for the idle step solenoid? The car ran fine with the wrong prom in it and i went to try another ecm to try and clear my code 51 and after reinstaling the same ecm and prom combination the idle surged to 2500 rpm with no voltage coming out to the idle solenoid. Again thanks for the help this has become a headache for me...

 

As long as the BCC is the same then it is the same calibration. The ECM for your vehicle is the 1228746. This is the service no as found on the paper label.

RBob.