P06D3, Limp Mode and General electronic gremlins

[Wilder]

So I have been seeing some intermittent crazy behavior on my truck, (2022 Diesel). It will flash all kinds of lights on the dash - Service throttle control, service cruse control, service forward collision warning etc, and the throttle pedal doesn't operate correctly, it almost seems like its in limp mode, unable to accelerate over 10mph. Sometimes i start the truck and this happens, other times it goes days without doing it. I put a code reader on it and it was giving a P06D3 code, which is "Sensor Reference Voltage E Circuit Low". From what i can tell there are several sensors on this circuit, including the throttle position sensor, particulate matter sensors, and others. I have found several threads across the internet where similar issues are reported, but none give a final solution to what repaired the issue.

I have already replaced the batteries, which was one common suggestion, and that had no effect. I have service appointment scheduled (still under warranty) but the dealer is backed up for a month - Mar 11, and they suggested i rent a car (at my own cost) until they can get my truck in for service. Ram won't pay if i take the truck to an independent garage either. Basically means i am on my own to solve this. Does anyone have any experience with this issue? I am considering ordering a new throttle position sensor, as this seems the most likely. Beyond that, i would be at a loss. Any help is greatly appreciated.

 

[PRS]

You are correct, there are several sensors fed by this circuit. And, it’s like you’re in limp mode because it is in limp mode.
A problem in any of the sensors that draws the voltage down can cause the problem. Think of it like a weak short.
The way to find the culprit is to disconnect each sensor one at a time and measure the voltage to be 4.9 to 5.1 volts.
On my 2020 the sensors are accelerator pedal position, DPF differential pressure, and with a 68rfe the transmission pressure sensor. I’m guessing your 22 is the same but not sure.
There is also a splice in the transmission harness on the left side of the trans that could have a bad connection and cause the low voltage.
As you disconnect each sensor you could use some contact cleaner on the connectors to ensure no dirty pins are causing the low voltage.

Again, I don’t have anything in this other than trying to help, but Mitchell DIY has a nice write up on this, complete with good schematics, for a reasonable price.
Good luck.

 

[Wilder]

So I was going to replace the accelerator sensor, but ended up getting in at the dealer. The dealer determined that it was the accelerator position sensor, and they replaced it. The truck ran fine for ~600 miles.

I then took the vehicle on a trip to Canada, and the issue started happening again. Stuck at a dealer in QC, wondering if there's a broken wire somewhere in the system

 

[Wilder]

Update for anyone else who has this problem. It was the DPF differential pressure sensor. (This was replaced under warranty over the summer) It shares a power supply with the accelerator pedal sensor, so if one sensor has a short circuit the rest will stop working as well.

Shame they couldn't figure this out at the dealer back home, after the they had the truck for a week. It took le mecanique only an hour to diagnose it, and a few more to get me back in the road.

 

[flan]

Update for anyone else who has this problem. It was the DPF differential pressure sensor. (This was replaced under warranty over the summer) It shares a power supply with the accelerator pedal sensor, so if one sensor has a short circuit the rest will stop working as well.

Shame they couldn't figure this out at the dealer back home, after the they had the truck for a week. It took le mecanique only an hour to diagnose it, and a few more to get me back in the road.

Thanks for the follow up post, pretty crazy how the 2 are related.

 

[werard]

Update for anyone else who has this problem. It was the DPF differential pressure sensor. (This was replaced under warranty over the summer) It shares a power supply with the accelerator pedal sensor, so if one sensor has a short circuit the rest will stop working as well.

Shame they couldn't figure this out at the dealer back home, after the they had the truck for a week. It took le mecanique only an hour to diagnose it, and a few more to get me back in the road.

How many sensors are on that circuit? Are both of those on the same one? If so it could be an wire problem/fuse box that is causing the sensors to fail?

 

[Wilder]

Reopening this discussion because the truck went back into limp mode. At this point we've replaced the DPF pressure sensor and the accelerator position sensor. After replacing a sensor, it works fine for a while and then eventually fails again. That has to be a clue right? Is there a reset procedure that would be done after replacing any of these sensors? Something beyond just clearing the codes? If no broken wires, which is what the dealer has told me, at this point I'm suspecting an ECU issue.