Hipithetical Question
 

Hipithetically speaking, if a guy had 2 identical HHRs, same year, same model, same equipment. You took the ECU from one and put it in the other car, besides the radio not working, would it function for a temporary test, say a smog test? I'm not concerned with the vin plate, only what the obd2 reader would see. Hipithetically speaking, of course........:smile:

All things being equal, yes all but the vin matching, there should be the same readings on the obd2

Except that I/M would report "not ready for smog test". And you would have to re calibrate the Crankshaft position sensor. And the VIN is reported by the ECM, It would not match the plate. And test like O2 sensors are continuous, as soon as you turn the key it looks for the heaters then the signals.

If the aim was to just be able to drive, that would work fine. Smog testing, no.

Why would the crank sensor need to be calibrated? The stock HHR ECU would be going in a stock identical HHR. Not matching the vin plate is not a concern.

That's what happened when I put a Programmed to my VIN ECU in mine. The book says you have to do it when you R&R the harmonic balancer or change the ECU or change the sensor..

relearn is the correct word, not recalibrate.

Thanks, that's good to know.