2014 Ram 3500 6.4 gas engine. "Service Electronic Throttle Soon" light

Intermittent problem with "Service Electronic Throttle Soon" light coming on. Accelerator pedal goes dead and truck goes into limp mode with check engine light on as well. Restart truck and it will run fine sometimes only for a short while before failing again or will run a few days before failing again. Some codes pulled when it happened. P1628 P2173
I am told there is a possible short to ground in the 5v system.
So far the following have been done. MAP sensor replaced. Pedal assembly replaced, throttle body replaced, Camshaft sensor replaced. Still having the problem. In fact after the throttle body and camshaft sensor replaced it happened an UNUSUALLY number of times the next day.
Almost 30 failures within a 20 mile trip.
Only happens once the truck is warmed up and only seems to happen when going from a stop and up around the 2nd, 3rd gear. Never happened at high speed.
Dropped it off today at different service station. Hoping they can track down the problem.
What other sensors are on that 5v circuit? Anybody experience something like this? What is next direction?

Interesting issue, JackR. :blink: I'd love to hear what this new shop has to tell you when they report in.

The P2173 is usually described something like, "Throttle Actuator Control System - High Airflow Detected". I think of it as a rationality code. The PCM is calculating how much air should be flowing into the engine based on engine speed and throttle position, and compares it to the ACTUAL calculation based on the MAP sensor. When the two don't agree, the PCM assumes an issue and sets the code.

Anything that'd change airflow in the intake is suspect. Vacuum leaks, PCV issues, aftermarket plumbing, like that.

The P1628 is tougher. Do the two codes always set together? If so, I'd figure the P2173 is a symptom, and the P1628 is the code to follow.

I don't have access to service info at the moment, so I can't say which 5V reference circuit the code pertains to. If this were in my bay, I'd want to hook up my scope to both 5V reference circuits at the APP and go for a drive. If/when I see one drop out, I'd pursue that circuit for shorts or sensor issues.