2011 Durango Start/Stall

I need to pick someone's brain here....

2011 Durango Crew, 5.7, Auto. Came in on a roll back with a start/stall condition. Vehicle would crank, fire, run 1-2 seconds and die. Like theft system shutting it down. Got it into the shop and scanned for codes. Nothing in engine related. Several modules had comm codes but what Chrysler product doesn't at 10 years old. Tested fuel pressure, volume, and pulled a fuel sample to check for water. All OK. I used a circuit breaker with a wire loop to bypass the ASD relay and tested the cam and crank sensors with scope. Crank wasn't a good square wave so I got the car up in the air and checked power, ground and signal. Had good readings on all three so popped a crank sensor in it. Pattern better but same problem. It was 5 on friday, so I went home to stew on it.....there

Long story short, came in today and checked all the above again multiple times. Never loose cam and crank signal or fuel pressure. Did a throttle follower test. Scoped both ignition coils and injectors. Both have good patterns for the few seconds it runs. I noticed that a lot of the modules are on the low speed CAN network so I started poking around under the TIPM. I thought the low speed CAN was down, but I think it was my back probe not making good connection. However, CAN high and low are both the same with a slight voltage difference. Shouldn't one of them be inverted?

In, my gut, I'm feeling like this is a network issue where the PCM is not getting a good signal from something to do with the security system, but I can't come up with a way to test my theory out. Right before I came home, I noticed that there is a second high speed CAN that connects to some of the modules in the network. I am inclined to test those in the morning.

Oh, by the way, this isn't this old gals first rodeo. Someone has bypassed the on board fuel pump relay with and external one and it looks like a well done repair. Since I never loose fuel pressure, i'm willing to let it slide.

Any ideas?

Wonder if you can unplug the cam sensor and let it run on the crank alone? Can you keep it running on alternative fuel? Maybe plugged converter??

Have you checked the fuel pump relay circuit at fuse M25 in the TIPM. Read 2011 Durango's have this problem.

i'll try that! Thanx for the response!

i have been from the front to the back of this fuel pump circuit. I'm sure there isn't a problem with it! Thank you for your input!

How’s the 5 volt reference look? Keep it or lose it

Seems M25, not the fuse but the circuit within the TIPM at M25 which supplies the 12v for the relay fails. Check to see if you have 12v at the back pin. Remove fuse and use volt meter to see a steady 12v when running. If it fails to maintain the 12v the FP shuts off.