Bought my 16 year old an older pickup for his first car, 2002 Dodge 1500 4.7 liter. 175k miles, motor runs flawlessly and got a heck of a deal knowing it would need a little tlc. We live in Collin county so I still have to get the emissions test done annually and it’s throwing a code, p0601 which is for the pcm.
After researching, there are a ton of things that can cause this code aside from a worn pcm. Not noticing any issues like shakes, gas mileage is a little low around 14mpg on the hwy. but again, runs really well.
I’ve replaced the tsp, map sensor, cleaned battery, found an air leak in the evap system which I’ve repaired. Went ahead and cleaned the battery connections which temporarily removed the code.. I’ve check the connectors to the pcm which seem to be in good shape. I’ve since tried to delete the code but it continues to throw on a second start up.
Quote from a shop (over the phone) is around $1100 to replace and have found some online for around $300 that will come set with vin and mileage.
Any other things I should check before buying a new pcm?

Do you know for sure that it will fail the emissions test?

(I have no clue how an emissions test is done because I'm in a rural county)

Yeah, if they hook up and receive a code, it’s a fail per the shop

That sucks. I bought my daughter a similar vehicle. 2005 Ram 1500 4x4 with the 5.7 liter. Runs great, check engine light stays on, but luckily it doesn't matter here.

Just in case I would try a new battery or a known good battery before going to all the expense repairing the pcm failure. I know in newer Rams a not so obvious failing battery can create all sorts of wacky problems one would not think could be created by the battery. I have seen lots of threads on Ram forums or groups from people (and dealers) chasing gremlins with no luck, then the problem only going away after replacing batteries they did not think had a dead cell or whatever going wrong with them.

I can second this from personal experience.

Yeah, that makes me think it's an electrical problem. Bad/loose ground, low voltage or something of that sort. I'm not a mechanic, but I deal with electronics every day. Is there a way to check the supply voltage at the PCM?

Possibly. I have tools, just need to look it up on YouTube
I’ll check the battery after work

Delete all the codes. That is what you did when you disconnected the battery. I had a 2000 Dodge Ram Diesel. All the lights in the dash went out. Nothing would work except you could still drive it. I got it home. Hooked up my cheap scanner to it. Started deleting all the codes. When I finished everything started working. Never had another problem while I still owned it.

Kudos for helping your son with his first truck !! Good luck on repairs

Carefully check your pcm wiring harness wires anywhere it might be rubbing on chassis, frame, anything metal, etc.
On older vehicles Can't tell you how many times I've found the wiring cover brittle/cracked/gone and the insulation on the wire rubbed thru to the conductor shorting out somewhere...

Will do

I’ve deleted the 1 code twice now, but 2 starts later, it reappears

If you can, temporarily swap the battery with a known good battery. Say, the one in your vehicle. Clear all the codes and start to truck several times to try and duplicate the p0601 code issue. If the issue persist, move on to something else. If the code is no longer being thrown, replace the battery.

New battery was a no go. Temporarily cleared, returned on second start. Cleared code but continued to return.
Checked all grounds (I think), checked all fuses. There’s a few other sensors im going to check out. May end up paying the $169 diagnostic fee just to be pointed in the right direction.

I’m following this, I’ve spent some time searching google. Everything I can find points towards a failed ECM or the ECM needs an update.

I am not Dodge guy but here's some information that might help. Any P code who's first number is ZERO is a Federal code that is basically the same for all makes. If the first number after P is a 1 then the code is brand specific. That being said, a P060X (where X is a number) is 90+% a new PCM for a GM vehicle. Being the age it is it's likely a used PCM can be programmed to your VIN. It's not like that any more (with GM) as the new ones are one time programmable (without proprietary equipment). This means you can get one from a junkyard super cheap and give a Dodge tech a case of beer under the table to get it programmed.

Hope that helps.

I thought about the junkyard too, but a case of beer to a mechanic makes that plan more enticing.

Checked the o2 sensors last night. I honestly believe they’ve never been changed, so ordered a couple. Since this code fires routinely on the second crank after a reset, and after finding the hole in evap system, I’m leaning towards an issue with air/exhaust. So, replacing a few more sensors in addition to the o2s and going to do another round of checks on those lines to the charcoal tank/evap system.

I should add this truck was in Colorado for many years and rust is showing up underneath so the ground checks were a must. Thanks for the mention. And with that type of extreme weather, a leak/moisture getting into the pcm/is highly likely.

P060X has nothing to do with any other part on the vehicle. It's an internal problem the ECM. And BTW, another option is finding someone with HPTuners to turn off the P06XX series from reporting as well as P0420 P0430 P0442 P0455. it's against Federal emissions rules so don't tell us if you go that route. Should cost $200-400.

The reason I haven’t just pulled the trigger yet is because I’m not experiencing any common/obvious issues other than the check engine light. The gas mileage is around 14 on the hwy, so maybe. But no other shutdowns, shakes am I noticing that would be caused by a true pcm failure. The prior owner said it’s been on “for awhile” but never noticed any issues.

Noted

a bad bcm can trigger that code, too, as in also. and you have 4 control modules on that truck i believe, ecm, bcm, tcm, and an abs control module

O issues with the transmission or brakes(no abs light), so I don’t think it’s those, but I’ll look into the bcm. Thanks

More than four and doubtful a body module can turn on a Check Engine light on a vehicle that old.