No Crank, No Start, No Comms

Issue: No Crank or Start, more below...
Year: 2007.5
Engine: 6.7
Trans: 68RFE automatic
Mods: Full delete, RaceMe tuner running mild +40hp standard tune, Edge Insight CTS2 with EGT probe, Lots of suspension mods from Thuren probably not relevant other than there has been a lot of welding and plasma cutting done on the truck (possible electronics issues??). Some accessory lights but they are wired directly to the battery with relays except for the rocker switch lights which are tapped into power under the dash.

Owned the truck for 3 years now and it's been amazing until I took it in for an alignment last week and the mechanic could not start it after the work, dead on the rack. No history with the shop but they have good reviews although they did seem to struggle with what should have been really simple and then claimed a cam bolt was stripped and wanted to keep the truck overnight to order a new bolt. I agreed and late the next day is when the problem was discovered. Truck supposedly had the key on for a long time while they messed with the alignment and battery voltage probably dropped somewhat since I hadn't been driving the truck in a while before this and the Edge was plugged in. Still haven't figured out if they did anything malicious or it was just bad timing and from leaving the key on.

Active codes: U0100, U0141, C2202, C2206
Stored codes: B210D U0184, U0164, U01019 and repeats of the above active ones

The above codes are from their scanner. I plugged in a cheapo code reader and it didn't show anything. Plugged in my RaceMe and got CAN error#121 with no communication. Tried the Edge and it wouldn't communicate either. I have an x431 coming tomorrow to help with the diagnosis.

Any ideas on where to start? I did find a 2 year old thread on here of almost the exact problem and messaged the OP, hopefully he is still on here as the thread did not come to a resolution.

Is the battery voltage getting low with the Edge plugged in possibly a cause for this or some other random thing or does this strongly point to the shop trying some shady things with my baby that I need to really look into?

Thanks!

Forgot to mention. Batteries have since been charged. Also, I've already tried disconnecting batteries, pulling IOD fuse and inspecting other fuses with no luck. Also, PRND lights are missing from dash but "check gauges" ABS and check engine are on with key on.

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Originally Posted by PhilR

Forgot to mention. Batteries have since been charged. Also, I've already tried disconnecting batteries, pulling IOD fuse and inspecting other fuses with no luck. Also, PRND lights are missing from dash but "check gauges" ABS and check engine are on with key on.

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Have you load tested batteries? Voltage is okay but if amps are down your truck wont be happy!

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Originally Posted by TexNeck

Have you load tested batteries? Voltage is okay but if amps are down your truck wont be happy!

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So the shop did load test and said they showed good on their tester even before topping off the charge although that may have been with both batteries still connected which would give a lot of amps. Also, we tried monitoring battery voltage while key was turned to start (again before charging) and it was only getting down to 11.9V. Definitely low but from what I've read not low enough to take down the communication line and disable trying to start. Also, batteries are about 2.5 years old. At first I had wishful thinking it was something that easy but afraid it's not :(

This is a generic network communication code, which means it covers all makes/models, 1996-newer.

However, specific troubleshooting steps will vary depending on the vehicle.

The generic OBD trouble code U0100 is a serious situation where the signals between the electronic control module (ECM) or the powertrain control module (PCM) and a particular module have been lost.

There could also be a problem with the CAN bus wiring disrupting communications.

Read more at: https://www.obd-codes.com/u0100

Copyright OBD-Codes.com

I wonder.

OK, so an update and definitely curious if anyone has opinions on the root cause of the issue.

I ended up reflashing the ECM/PCM with a recovery file from the tuner and then the standard tune I had been running and everything went back to normal, no error codes and the truck seemed to run fine. I took it out for a drive and around the 4 mile mark it went crazy, felt like it went wide open throttle for a second or so then completely shut down going 60mph which was scary to say the least. I tried flashing with the recovery file again to limp home but it wouldn't work even after disconnecting/reconnecting the batteries so I had it towed. After sitting overnight and also disconnecting/reconnecting the ECM to recheck power and grounds I tried the recovery again and this time it worked which was surprising. However now the truck has "incompatible injector data" codes for all cylinders so it looks like maybe my trim codes were corrupted.

At this point I'm too afraid to drive it again without having some hope that I understand the issue and correct it. I did send the ECM off to possibly be rebuilt/checked. I've got 3 causes I'm entertaining:

1. ECM is bad and fails under certain conditions (bad memory, micro cracks, etc. honestly not sure)
2. Another module or wiring issue is taking down the ECM and corrupting it. (wiring on truck generally doesn't show signs of aging or issues)
3. I performed the recovery flashes without adequate battery voltage which caused some really odd problems. At first I didn't think this was possible and that if the flash went through without errors then it was OK but I've read a few things that seem to say different. My batteries are at 12.3V and the grid heater did cycle on during the first part of the flash which I'm sure dropped it further.

Any votes on these or something different? Thanks!

My guess is a failing ECM.

Ray,
Double R Diesel

Unfortunately I cannot help but following to see the results.

Greg
2012 | RAM 2500 | CCSB | Custom tuned by Double R Diesel
2016 | Heartland Pioneer | DS310

Quote:

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Originally Posted by DRD

My guess is a failing ECM.

Ray,
Double R Diesel

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Thanks for the vote and I'll let you know when I find out.

Just hoping it's something clear cut like that and the issue is solved.