steveczi

What's the difference between a ecu and a pcm?????

kevinkpk

ECU is the electronic control unit, pcm is powertrain control module. I am NOT an expert on any of these although I have a 96 lumina that constantly gives me problems. What I posted was what I read in my Haynes manual covering my 2000 Suburban. In that the PCM as with the lumina controls the injectors.

steveczi

Well I was told from the chevy dealer the ecu was a engine control unit. I bought a used one and had the dealership flash and program it. I installed and you guessed it. I'm still getting po305 misfire I'm lost, Next I'm trying to check and or change valve springs on #5. If this does not work its off to the metal shreader

kevinkpk

The pcm is what controls the injectors.

steveczi

As you can tell I'm not real good at trouble shooting where would I find the pcm??
The ecu was on the drivers side inner fender and had 4 large electric plugs marked black white red blue. By the way I really thank you for your advice I'm flippin lost

kevinkpk

Look back where the coil packs are, plug wires

shamrock246

the PCM is the one on the wheel well on the drivers side,just below that is the anti lock modual,the ignition modual is located over on a heat sink on the passenger side rear next to the ignition coil i think you have the same setup as mine, that PCM controls everything in the engine and trans (ignition timing,shifting,fuel injection timing etc) if your getting a good signal to the injector on #5 than it's something mechanical with that cyl,ignition related or there still something wrong with your injector spider assy,if you get a good compression hot and cold then mabye a long shot is that there's something wrong with the valve train (flattened out cam lobe etc)
i'm thinking the spider needs to changed out with the upgraded assy


Sean

97 4x4 burb

steveczi

Hey shamrock thanks for the leads