I'm having major electrical problems with my '03 CTS. The tech says it needs a new ECM. I've found a salvage one that is considerably cheaper than a new one, but none of the numbers on it match. I've been told that they don't necessarily need to match as long as it is out of the same year and model because it needs to be reprogrammed anyway. Is this the case? Also, is an ECM the same as an ECU?
Symptoms: fuel gage does not work, key cannot be removed, will not shift from park.
Thanks, RB

 

the number should match. ecm or ecu are not always interchangeable. If your search your ECM number it may show numbers that would also work. Not sure about diagnosis

 

You are missing power. This might be a bcm issue (body control module) Not ecm
The ecms do fail since they are mounted directly to the engine.

I think you have a different problem.

 

Ordered a refurbished ecm from Chris @ Rippy's cadillac. Their pricing was competitive with any other source. Had the ecm installed and programmed and I'm glad to report it fixed my issues. If you need any parts, I highly recommend Rippy's! Good pricing, friendly service, quick delivery.

 

I would not recommend buying a salvage ecm. i first had mine reflashed since that was supposed to fix the "problem" but instead I got a new one from the dealer and even yet I still manage to have problems. But in my case, warranty covers all problems. Either way our first gen cts's have major problems with ecms, they always go bad. Don't risk it!!

 

2003 Cadillac CTS ECM on Mintt for future reference are pretty cheap on there instead of all the guess work