[rfugere03]

So I have an 08 Sierra 2500HD with Cognito 6" lift. Fass 150 lift pump, deleted factory fuel filter, larger CP3 inlet and outlet fittings
Banks Doubleshot water methanol system
Banks ram air intake/super scoop
Modified fuel rail with ported inlet/race plug
Dpf and egr deleted
High flow Y-bridge and intercooler pipes
PPE high flow race exhaust manifolds and up-pipes
3" SS downpipe
Transgo jr shift kit

The truck was collecting dust in a barn for about a year until I found the time to replace the water pump and at the same time i installed a Danville Performance 65mm stage 2 turbocharger w/ high flow vanes, PPE coolant hoses, PPE coolant overflow tank, relocated passenger side battery to frame & AlphaRex LED headlights. [Not sure if it could have anything to do with it but I also replaced my High Pressure A/C switch pigtail because the clip on the old one broke.(I'm 98% sure I wired the pigtail up correctly but I did notice afterwards that anytime the air recirculation button is on, the a/c compressor is engaged regardless of whether or not the a/c button with the snowflake is on. I didn't think the compressor should be engaged w/out the A/C button on but after a year I couldn't remember.)]

It ran good for ~6 months but yesterday I took it to the dump and on the way my Brake light came on as well as a service trailer brake message. At the dump I turned the truck off and a few minutes later went to start it and had power everywhere but no crank.

I didn't have my flashscan v2 but I had an H&S xrt pro so I used it to clear the codes (I foolishly didn't pay attention to what codes they were I just cleared them) but no dice. Then I went through the majority of my fuses that I thought could be it but they were good. I decided to check codes again but this time the reader said it couldn't connect or receive information from the vehicle (I should've snapped a picture of it but didn't)

So I had my brother in law meet me to tow me home but before hooking it up I decided to disconnect both batteries for a few seconds and then reconnect them and sure enough it fired up and I drove it home.

But none of my gauges worked except my battery voltage indicator, the line under my shift position indicator was not showing. I didn't scroll through everything but my average mpg is what came up and it was just showing lines. My air worked but I assume the compressor wouldn't engage or didn't get a signal because it just blew hot air so I shut the a/c off.

When I got home I turned it off then tried to start it back up but no crank again. I checked the codes again and this is what came up.

Any ideas on what else to check would be greatly appreciated.

 

[rfugere03]

So I got home from work, tried to start it and it fired right up. A few seconds later the ABS and brake light came on as well as the service trailer brake message. Then I turned it off and tried to start it back but once again no crank. Here are the codes I read w/ my flashscan.

 

[Ron Nielson]

Did you look up what those codes mean and what causes them? Start with one I picked at random. P154D - Chevrolet Diagnostic Trouble Code (DTC) Definition, Causes and Diagnosis Most of the others will be there also. By the way, "P%" codes are for the engine and the "U%" codes are communications errors on the GMLAN system.

 

[rfugere03]

101- lost communication w/ tcm
140- lost communication w/ body control module
1041- I believe is lost communication with ebcm

The rest are codes from deleting the intake air heater and other modifications

 

[bellassaiw10]

triple check all ECM connections at all points, to include everywhere around where you were working. Amazing what little things can cause problems with the ECM I had a ton of issues with poor connections.

 

[rfugere03]

Alright so I'm pretty sure it's the BCM because yesterday I tried to start it and the same thing happened no crank. Then I got down, tapped on the BCM, pressed on all the connectors and then it would start.

 

[2fastlx]

Check the ground wire connection on the drivers side frame. Right about under where the drivers feet are. It's on the outside of the frame easy to see. It's a common issue and can cause all sorts of communication issues.