Mpvi2 not talking to PCM please help

So i was tuning my truck I put a tune in it didn't like so I went to back up a step and put the tune in right before changes and nothing it says failed to connect to PCM. I put a ticket in to hptuners support and gave them the info they needed. They emailed me saying the ABS and the BCM are blocking HpTuners from connecting. Has anyone had this happen and if so what fixed it? I tried pulling fuses to both the ABS and BCM like support suggested and still nothing. Thank you in advance. Also I've used the Mpvi2 on another truck and worked no problems

Quote:

---

Originally Posted by X_Racing1

So i was tuning my truck I put a tune in it didn't like so I went to back up a step and put the tune in right before changes and nothing it says failed to connect to PCM. I put a ticket in to hptuners support and gave them the info they needed. They emailed me saying the ABS and the BCM are blocking HpTuners from connecting. Has anyone had this happen and if so what fixed it? I tried pulling fuses to both the ABS and BCM like support suggested and still nothing. Thank you in advance. Also I've used the Mpvi2 on another truck and worked no problems

---

What truck are you working on?

Sorry I?m old lol 2002 Chevy Silverado 2wd 5.3

Very seldom do I see problems connecting to a 411 PCM. Now, the 2003-07 P59 PCM's are a different story.

Make sure your vehicle battery is good. Also look for corrosion on the OBD2 connector.

Verify ground at DLC #s 4 & 5 (uncommon cause), and power at #16 (extremely common cause).

At the dealership it was a weekly thing where some customer's idiot kids would shove pennies into the lighter sockets, pop the fuse, and then I get stuck with no-comms with the scan tool.

It's real common on these for after market radios to cause no comm issues with the newer mpvi's - see it constantly. The older ones communicate without issues on the same vehicles. If you don't find any power or ground issues at the data link you might also want to try unhooking - not just pulling the fuse either to the radio - unplug it. Had to do this quite a few times with the newer mpvi's on the older silverado's in regards to the year model your having problems with.

OK tomorrow I will look at all of that and report back thank you so much

So I have tried everything took radio out checked all grounds. I have built a bench harness and still could not talk to my pcm. So I thought I bricked the pcm. So I bought another one and everything worked on the bench harness but I put it in the truck and nothing pcm won’t talk to my laptop. I took it back out and bench harness does work. I put a tune in it and the truck runs but it’s rich my problem is I can’t collect data. Any thoughts?

Tell me if I’m wrong but, can’t I put my own obd2 port in and bypass all the truck wiring?

You might want to confirm the data path is complete. I think this will apply to your vehicle
http://resources.aeswave.com/ATG-05_...%20may%20occur.
See page 3

Probably easier just to post this.

https://www.youtube.com/results?sear...silverado+1500

Some of these videos will go over how to check your communication networks to the ecm. You'll have to check resistance for 60 ohms (think it is - has been a while) on your class 2 and look for bouncing mv comm voltages.

As a quick thing though - are any other modules not working or is anything else on the truck not working. You have to have two terminating resistors - each 120 should change to 60 if both in circuit. Again - think that's right, but not 100%. Power and Grounds and active communication.

I remember these having a communication bridge somewhere around the steering column that was bad to corrode or have wires break if you find a lack of switching voltages or anything. If everything is working on the truck then it's from the ECM to the data link that needs checking or from that bridge to the data link.