daveS

I've got a 2013 430hp GM connect and cruise package in my hot rod. I had it running in 2014 and used an HP tuners device to make small changes to the idle speed.

I took the car apart for paint and other finish work and have it running again. The engine seems to run fine and shows no error code light, but there is no communication possible through the OBDII system, regardless of what I hook to it (code reader or HP tuner). I have Speedhut gages that get their info from the OBDII system and they don't work either.

It's not the OBDII plug because the gages are hard wired, before the plug.

I've got no clue what to check. Lack of grounding in not likely. There are three computer plugs and each bundle of wires has it's own ground terminal that's bolted to the cylinder head.

I also have a USB port on the transmission controller that hooks to the OBDII system. It won't communicate either.

Any thoughts?

Mercier

iTrader: (15)

We have to get some of the stupid questions out of the way. Sorry, but I'm a "is it plugged in" troubleshooter. Check your fuses? Are you attempting this with the key all the way "on?" Do the Speedhut gauges plug in with a sort of piggy-back connector or otherwise? If so, have you tried removing that and plugging HPT directly in?

When plugged, do any of the lights on HPT box itself come on or completely dead?

Have you driven it, and does the transmission controller function properly other than the data port? Have you pulled each of the computer plugs and inspected for moisture/corrosion(yes; unlikely)?

daveS

I solved my problem the expensive way - bought the latest TCU and wiring harness from GM. That fixed the problem. The computer is a new style with a rectangular plug instead of a round plug, but it's still provided by PCS.

The problem with GM and PCS is that neither one will provide ANY advice or assistance to the consumer. You can take your car to a GM dealer and pay $95 an hour for them to diagnose the problem. Since the TCU would not communicate with my laptop, I figured it was fried and needed to be replaced anyway.

Mercier

iTrader: (15)

Yep. I am going to invest in a Tech II/2/whatever the proper name is for that reason. Getting into some of the later stuff(the V) where the radio and such has to be programmed together.

And like you, I would rather pour salt in my eyes than pay a GM tech to fu*k up my vehicle.