PCM swap

[Antwan Dundunitall]

Is it possible to use a pcm programmed for flex fuel on a gasoline engine? I found out that the junkyard sold me a PCM with an 8th Vin of Z(flex fuel), but my truck's 8th Vin is a T(gasoline). The truck idles fine but won't accelerate over 40 mph. Thanks!!!

[riverbanks]

I personally wouldn't risk it,get the right# one or go elsewhere, nothing is easy anymore

[davester]

From what I've read (as in, I'm pretty sure, but I don't own a truck w a flexfuel system), there's a sensor for the pcm to tell it what kind of fuel is in the truck, but your truck won't have that sensor, so the pcm is likely confused/erroring out because it's not getting the signal for it.

[CamGTP]

Depends on what year the truck is. Most have virtual sensor that just use the fuel trims and some have a real sensor it would be looking for. If should have tossed several codes if that sensor wasn't in the wiring.

 

I'd have a dealership flash your new computer with the most updated factory file for your VIN number. Then you know it's 100% right.

[Antwan Dundunitall]

Thanks to all of you for your responses...@devester and CamGTP the truck is an 03 Silverado 1500 the donor PCM is out of an 03 Tahoe with the exact same service numbers... However, there is one DTC coming up P0178, It's for a fuel composition sensor.... The 'Rado doesn't have that sensor on the frame rail at all. Like you guys said it measures the amount of ethanol etc in the fuel that passes thru it. I guess it's time to get it reprogrammed or flashed with my trucks Vin number. Because it even comes up as a Tahoe on my scan tool. Thanks for confirming that for me.

[sefiroxx]

Yes, a reflash is needed. Ethanol based fuel runs at a different air/fuel ratio so the computer need to see how much ethanol is in the fuel.