Nickie Montealegre Prado

Hey what's up everybody,

I'm new to the forum but im desperate for some help. I recently did a v6 to v8 swap on my truck. Trucks an '09 Silverado that was a 4.3L and we swapped in a '08 5.3 with a stage 3 cam. Shop was getting ready for it's first start but the truck threw a code, P1631, the theft deterrent code. He figured it was the VATS, so he did a VATS delete through HPtuners and that didn't work. Flashed the ECU, tried the security relearn, etc., everything online that it says to do we've tried and nothing worked, despite the majority saying all it needs is the security relearn. So we're pretty much stuck right now and are not too sure how to clear the code. He's thinking it has to be either the ECU or the wire harness, because the wire harness is from a 2013 which he said was made for a fpcm and my truck doesnt have one so he bypassed it and ran a relay to the fuel pump. Any ideas or suggestions on how to get this thing started? I'm about to place an order on a new e38 ECU just in case the one he tried using was fried. Other route is to go for another wire harness but that's even more costly.

Heres some info that pulls up on the log :
Stage 3 Cammed Cast Iron 5.7 (5.3 but bored it out)
- Injectors pulsewidth to 27.3 ms while starting
- TPS % is at 32.5
- commanded AFR is at 5.42 when it should be at 14.7
- has crank cam and map signal so harness and ecu are communicating

Anything would help and be greatly appreciated.

2xLS1

iTrader: (25)

Does it crank but no start or no crank? What ECM is being used? What was it flashed with? Year and vehicle? With problems like this you need to provide as much detail as you can since you chose to use mismatched parts from different year vehicles.

Nickie Montealegre Prado

Trucks a 2009 Chevy Silverado 1500 Base Model WT - 4.3L with stock 4L60E transmission.
Kept stock tranny, threw in the 2008 5.3. Yeah the problem with the harness was whoever I ordered it from had it listed for a 2009, which the VIN verified. But shop was saying the one they sent did not match up with a 2009 harness, as he had to pull parts from a 2013 wire harness for it, so he was saying they sent the wrong one but he was able to work with it.

- It doesnt crank, so he ended running a wire to start.
- E38 ecm
- flashed with a 2008 silverado tune using HPtuners - also tried a 2012 tune as well
- was not getting power to fuel pump so he ran a wire to it too.

2xLS1

iTrader: (25)

Sounds like you need a shop that knows what they are doing. Customer shouldn't have to go to a forum to figure it out for them. Your post is still a bit confusing. You don't just pull parts from a harness. Since you are not the one programming it I don't suppose you know if he did a write entire after disabling the VATS. You have to on E38s. Did he try disabling the starter checks? Did he try disabling the code? So the E38 is a 2009?

RySmDPT14

Have you gone to HP tuners forum and asked the same question and I suggest the “shop” you took this to needs to go to HP tuners and post the tune so people can look it over and see what is wrong.