After rebuild no crank/no OBD2

H

Hoiyay

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Dec 10, 2018
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74
2006 Megacab 5.9
Just finished up a several month long rebuild on the cummins. Got fluid in the truck and went for first crank. Nothing.


It acts like it wants to crank over...the radio resets, some of the lights on the dash go off, but nothing.

I did do some gauge install and did a bit of wiring/splicing but nothing much. Essentially I piggybacked into the pink/yellow wire in the "100 pin" connector to get my ignition power for my gauges. I tapped into the orange wire for the illumination. And everything else I ran directly from the batter with fuses. So shouldn't interfere with anything else.

I'm completely baffled by this. I checked all of the fuses in the TIPM. Used a volt meter at first, after some frustration pulled every single damn fuse out and looked at it just to make sure. They are all good, and all correct size.

My red dot "wait to start" just blinks the entire time. Odometer reads normal. Engine and ABS lights are on. Check gauges light is on, etc etc.

I've read these trucks are notorious for issues with the TIPM and that can cause some possible issues I've had. Don't think there's anyway for me to single this out though. Some people have said they had theirs reflashed at the dealer...I'd probably have to take my entire truck up there though (tow it). I also read that if you disconnect both battery cables for about 10 min it should automatcally reset the TIPM...I did so and no dice.

I've even ran brand new 2gauge jumper cables to the PCM grounding stud and also to the engine block and frame to try to make sure im getting a good ground. No changes.

Really stuck and really just want to be done with the truck.

Any help is appreciated. Any explanation of how the systems work would also help troubleshooting as well. Thanks guys.
 
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Will add, Most everything works on the truck...I know the fuel pump is working. I can hear what Im assuming is the grid heater working at first key on. my locks, windows, radio are all working.
 
Just noticed, my gear indicator isn't working above the odometer...just blank.

Also, I got it cranking now, starter wire on solenoid was just barely not plugged in all the way.
 
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Hoiyay said:
Just noticed, my gear indicator isn't working above the odometer...just blank.

Also, I got it cranking now, starter wire on solenoid was just barely not plugged in all the way.
Click to expand...




Cranking but not running?



Thought about pulling your splice off until you get it going to make sure you don't have the wiring issue?


you getting any codes?
 
Timbeaux38 said:
Cranking but not running?



Thought about pulling your splice off until you get it going to make sure you don't have the wiring issue?


you getting any codes?
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Not running.

Can pull splice and try.

No codes because there's no obd available. It can't connect to truck.

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flashing wait to start means no connection to pcm or fried pcm I beleive
 
I would double and triple check the connections going from the engine harness to the truck at the firewall by the master cylinder. Make sure a wire didnt get pushed out, and that the connections are 100% pushed together and locked, making good contact.

I had truck do the same years ago and that was the issue.
 
UPDATE:

The truck does fire up and run...but only momentarily. I cranked and cranked and cranked, and it surprisingly fired right up and ran for about 3-5 seconds and then died. While running it surprisingly sounded rather decent. Tried it again and took probably 8-10 seconds of cranking and ran for 3-5 seconds again and died.

I have checked and checked every bit of wiring that I can. I ohmed out all of my grounds. Negative battery terminal to: Engine block, firewall, chassis, the stud by the tranny on the cab where the grounding strap goes, all the firewall grounds, the ECM grounding stud, etc etc etc. I am grounded out for sure.

My OBD have power and ground to it as well. I'm not familiar with CAN BUS systems so Im not sure how to measure those out honestly. And I feel that, that's where the problem lies. I feel like the truck isn't talking to itself. Nothing is talking to the instrument cluster that's for sure.

It may be that my ECM and my TIPM are good and it's simply a problem with my instrument cluster?

I tried following the diagnostic procedure for the lost communication of ECM from the service manual. But it's not matching up. It tells me to check the C6 connection at the back of the tipm. Then its asking me to ohm out wires that aren't even physically in that connection. I'm guessing the service manual is for a different year, even though it says for 2006 and I have a 2006. Maybe that tipm model is actutally a 2005 I have?
 
pushlar84 said:
Can u communicate with any other modules
Click to expand...
Not sure how I'd do that.

Are you talking about checking abs at the obd?

Tried abs, same thing. I already know my cheap scanner won't talk to tranny.


Did some testing and think I narrowed it down to tipm.

I have continuity from c6 connector at tipm to the obd for the can bus +/-. But no continuity between them at the harness. The FSM says to replace tipm at that point.

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Ok, got the new tipm in today and it didn't change a damn thing!


So, now I'm possibly looking at the cluster maybe?

1) Somebody explain how the anti-theft device works please. If anti-theft is active...will the engine start up and then shut off after a few seconds, or will it not start up at all?

2) does the gauge cluster control the anti-theft device?

3) does the instrument device also control the obd2?



Trying to figure out what controls all of my issues.

So far I have:
---no obd2 (power and ground are there, but no communication). CEL and ABS lights are on.

--no ABS communication

-- no gear indicator lit up (P,R,N,D)

-- red light flashing

What I DO have:

-- engine will crank up and run very smoothly til it dies after about 3 seconds. It then struggles to start again...I think this is because of it being a fresh rebuild and not having enough rail pressure?

-- ALL of my electronics work...radio, windows, rear window, lights, ac, blower/blend doors, (some gauges work, others not), heated seats, key fob works to lock/unlock.


I'm trying to figure out what this all has in common. I know the tipm can control all of these things, but that's brand new.

I'm thinking now that maybe the cluster is bad and the cluster is controlling the anti-theft shutting the truck off, and also controls or passes through communication to the obd? Possibly why it's also not showing gear indicator?

I've got nothing talking to anything. No engine data, no transmission data, no abs data, and possibly no anti-theft data.

What's the common link? Other than grounding.. trust me, everything is grounded the hell out. I'm even running jumper cables to various engine/frame locations to make sure.

Sent from my Moto Z (2) using Tapatalk
 
Hey the OBD2 power normally comes from your cigarette lighter fuse. And have you tried reprogramming your key, I know the Gm products you turn the key to the on position for 10 min then off for 5 sec do that three times and the Gm keys are reprogrammed and will normally start the engine and I had swapped my ECM in my 07 and without changing the vin to match the skim key on the ignition it started up twice and killed and then it would just turn over. So I bought an EFILive flashscan V2 and put my vin in and flashed my ECM and haven’t had a problem since.


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