FastCrewCab4x4

The neutral safety switch tells it that it's in park or neutral and stops it from starting elsewhere. Try putting it IN gear and starting , then neutral and try Just to confirm. The safety doesn't tell it what gear... if you temporarily disconnect the wire to pin 56 does it change anything? just a thought.

gmforlife

iTrader: (2)

This wont help but it does sound like Nuetral Safety switch to me.

Derek @ EDO

iTrader: (73)

Damn man thats weird, any other mods on the TBSS besides the Efans, I cant see the fans causing any problems since they are powered from the fuseblock where the battery connects to it. The e-fans only sense a ground from the PCM pin and a + voltage from the AC Comp. Trigger wire.

are the fans still working?

SNaray8442

Hey,

This truck belongs to me, thanks to all of you trying to help.

The truck has been modded with a p+p throttle body and a Vector Motorsports tune, otherwise it is stock in terms of engine modifications. The truck was running perfectly before the install started, so I don't think its related to anything else than something that went wrong during the E-fans install.

I tried starting it in D, didn't start, then started it in Neutral, and then again in Park. I tried taking the truck around the block an hour ago and it will not rev above 1500 RPM and doesn't seem to want to upshift. Seems like a limp mode to me.

On the dash, the speedo does not work, and the gear indicator is stuck on 1, no matter what.

Fans spin and look like they are working properly.

Let me know what you guys think, I can keep trying something else if necessary.

truckmann

iTrader: (8)

Hmmm That's strange for sure... I would try to disconnect the wire to pin 56 and see if it runs correctly. I would also double check to make sure that everything is wired correctly and there isn't power being sent to the through the wire going to pin 56. Sounds like it is wired correctly, but that is where I would start.

I would also be concerned that the scan tool will not connect to the pcm. I wonder if it the pcm may have been damaged or lost the tune somehow. Possibly needs a full reflash. Just some ideas off of the top of my head.

Do the fans run all the time or just when the engine is warm like they should?

Derek @ EDO

iTrader: (73)

The only other thing i can think of is unhooking the e fans, remove the pin and un tap it from the AC wire and see what that does, the fans are tapped into the correct AC comp wire correct? Check by looking at the color wire that connects to the compressor.

Derek

RandomHero

iTrader: (24)

Here's a decent but unfortunate update:
We've tried everything I can think of. I've spend a good 20 hours(that's not an exaggeration) searching for people who have had similar problems. The truck is now at the dealership because I have run out of ideas.

We've tried:
unhooking battery overnight
checking cables to pcm/tcm
disconnecting efans
checking a/c wire
plugging back in clutch fan
check fuses for everything relevant


The truck:
Won't read codes(even the dealer can't)
It goes in and out of limp mode
The CEL comes on and off(more on than off)
The fans run fine when the truck is on(a/c commands them right too)
The speedo also doesn't work and the gear indicator is stuck on "1" even though it will work in all gears.
Here's the most interesting thing:
When I went to check some of the cables on the PCM, it gave me a small shock. I have NO IDEA what this means but I'm sure it's not good.

ridnlow

iTrader: (5)

Are you having any problems starting it?? like every now and then you can turn the key but nothing happens??

RandomHero

iTrader: (24)

nope starts up everytime and idles like there was never anything wrong.

Lurius

iTrader: (7)

I have had some problems since my Efan install as well. I wired it to the PCM pin 42. I get "Service tire monitors", "Service break booster" etc in the DIC(trucks an 04).. Sometimes I even get "Driver door open"(or w/e). I juts clear'm off and ignore them. Disconnecting the battery and reconnecting helped once actually.

-Lurius