2014 5.3 swap won't start

[Genvswap]

I'm doing a 14 5.3 swap into a 06 jeep. I had the computer done by howel engineering as they are local to me. I went back today and had them reflash after a phone conversation trying to trouble shoot. We did a complete reflash and I'm still getting the same 7 codes and still no spark or fuel. I've done the starter relay resistor trick and he went thru all the vats tables. I'm wondering if he does not have updated software for the e92.

The codes are: p018c fuel pressure sensor low
P0192 fuel rail sensor a low input.
P127c fuel rail pressure
U0100

I had these codes before the reflash and he went thru and turned them all off but they came back. The u0100 has me concerned.

Any thoughts on this?
Thanks.

[Taz]

Did Howell also do the wiring harness, or did you rework it yourself ?

Is the Fuel Rail Pressure Sensor connected to the wiring harness (ECM) ?

Is the High Pressure Fuel Pump connected to the wiring harness (ECM) ?

Are you using a FSCM ?

If you are not using a FSCM, what PSI has the Fuel Pressure Regulator been set at ?

The U0100 DTC seems odd ... are you using an L83 (5.3L) throttle body and APP (gas pedal) ?

[Taz]

Re: U0100 DTC ...

I had assumed that you were also using the 6L80 transmission from the Truck ... is this actually the case ?

If you are not using the 6L80 transmission, then that could also be the root cause of the DTC.

[Genvswap]

It's a 6l80. And I have the factory gas pedal and ecu. It was all a take out.
The fuel rail sensor is hooked up and so is the high pressure pump. I'm not using the fscm. I had howel turn it all off. I did the harness and ive double checked every thing. But I do need to go over the trans wiring again. I pulled all the transfer case wiring out to use the jeep t case so I worry I may have pulled a wrong wire.

Would that code cause it not to start?

[Taz]

It sounds like you did a great job on the take out and retrofit work - no small task.

Can DTC U0100 (or its root cause) cause a no start condition - Yes.

What PSI is your fuel pressure regulator set at ? It needs to be at a minimum of 70 to 75 PSI (when not using a FSCM).

Without seeing the tune, anything else amounts to guessing. The no start could be a fuel pressure issue, a wiring issue, a tune issue - or any combination of these.

[Taz]

If you are located close to Howell, perhaps you could talk Troy into a house call.

If he could read out both the ECM and TCM tunes with EFILive, using the DLC port in the vehicle, then you could be certain the GMLAN (CAN Bus) is intact.

If only one of the modules could be read, then you could be certain that there is a comms wiring issue (which could cause the U0100 DTC).

[Genvswap]

Howel is 25 minutes away. For the regulator I used a 2010 vw jetta regulator /filter it's a 4 bar 72 psi just like the oem gm unit. With a walbro 90psi capable pump. I don't have the fuel line pressure sensor wired but it was turned off so it's weird I'm getting a code for that. Troy said the same thing today when we went over the tune and reflashed it. I'm going to go over my trans wiring in the a.m. I'm almost certain that's where I went wrong. I trust his tune he has done awesome work for me in the past. Thanks for help. It's nice to bounce stuff of some one. I've been tearing my hair out.

[Taz]

No worries - you are very welcome.

In a conversion vehicle the GMLAN will typically run from the DLC port into the 6L80, then come back out of the 6L80 (on different pins) and into the E92.

The connector on the 6L80 can sometimes be a problem. Make sure none of the pins have backed out of the connector. When you install the 6L80 connector into the transmission, the "lever" on the connector needs about a quarter of a turn (clockwise) to fully seat the connector.

[Genvswap]

Ok I think I found what I did wrong.

Xn pins 36 and 37 gmlan +3 -3 wires. I de pinned them. They run to the fscm. Since I wasn't running that I mustill of figured they were not needes.

In the schematic I see they run into the fscm and have a 120 ohm resistor inline. You don't happen to know what watt resistor that should be?

Now I have to wait for radio shack to open so I can go grab a resistor.

This could also be the the cause of my fuel pressure codes?

[Taz]

You don't need to add another resistor, there is already one in the E92 - you can add one if you want to - 1/4 watt.

The easiest GMLAN configuration in a custom vehicle, is as I described in post #8.

I don't have the schematics in front of me ... if the GMLAN ran through the FSCM, and you just unplugged it, then you should be able to simply bridge the comm lines (i.e. solder the matching pairs of wires to each other).

[Genvswap]

Well I connected those two wires and it cleared all codes except. U0100. I did a continuity test of the gmlan wires and I have a complete circuit.

I have nothing to hook the low speed (green wire) out of the dlc to as I don't have a bcm. I'm wondering if this could be a issue? I'm really at a loss here.

[Genvswap]

And I'm certain my transmission plug is working because if I unplug it i lose communication with my scanner.

[Taz]

Good job chasing the GMLAN wiring issue - wiring issues can be the most frustrating (and elusive).

The persistent U0100 DTC could be caused by the ECM and TCM not booting up at the same time, or not shutting down at the same time.

How did you wire the 12 volt ignition and Accessory Wake inputs to each of these modules ?

[Genvswap]

I left all accessory wake ups off. The gm performance info I got said they were not needed. I can put them back no problem (I was worried when I too them out ) would you suggest leaving those installed?

Right now I have nothing wired into the jeep. I'm using jumper wires for start and ignition. So the jeep is just a engine stand really.

[Taz]

GMPP (now Chevrolet Performance) ECM OS (operating system) is very different from a production vehicle OS - they are a stripped down version, with quite a lot of code deleted.

This powertrain package was a complete lift out from a 2014 truck. The ECM and TCM need to be wired like a 2014 truck. Not only are you missing the Accessory Wakeup voltage inputs, but I believe that it is likely that you are also missing at least one more 12 volt input circuit to the ECM (if you wired like a GMPP variant).

[Genvswap]

I did not follow much from the gmpp stuff. I figured it was different but for some reason I left out the wake up. I used stuff I found from many sources and loosely based it on earlier model stuff. As there is some cross over if you examine both schematics and pin outs. I used gm up fitter for most of my info .

[Taz]

It has been over a week since your last post .... I take it that you finally got the engine to run ?

Always nice to come back to the thread and post up your results / findings ... it may help someone else in the future.

[Genvswap]

Had to take it over to Howel. He reflashed with different software. But turns out I had the two injector harness plugs swapped....doh!

[Taz]

Wiring can be the biggest pain.

Are you happy with how it runs ? Guessing there has not been a test drive yet ?

[Genvswap]

Yea still lots of odds and ends before a test drive.