Viper ACR Arrow PCM problems

[Jack2o]

Recently purchased my 16 ACR she came with Belanger Headers & Mid Pipes w/ Cats and Arrow PCM. Had her stored for about 6 months since my house was under construction.
( removed battery ) Recently fired her up and my dashboard lit up like a Christmas tree with multiple errors

P0519 (idle speed performance)

P2127 (accelerator pedal position sensor 2 circuit low)

P2104 (ETC system forced idle)

I removed the PCM and installed my OEM PCM and only error was

P0430 (catalyst efficiency bank 2)
because of the Belanger cats.

Its pretty obvious my Arrow got reset and needs to be setup. I tried searching on how to set it up but no luck. If someone can help me out with this I would appreciate it.

[quickster2]

"because of the Belanger cats. it’s pretty obvious my Arrow got reset and needs to be setup"

Can you clarify this statement? If it came to you with the mods the PCM should have been "set-up". I would put the Arrow back in (assuming it came to you this way) and troubleshoot the errors 1 X 1. Can you reset the codes?

[Voice of Reason]

Did your battery die or almost die over winter? Dead or low batteries can throw weird codes that go away when charged. I doubt the Arrow PCM is causing your issues.

[Steve M]

it’s pretty obvious my Arrow got reset and needs to be setup.

While unlikely, it is possible.

Given the codes and the fact that it went into limp mode (P2104), I'd start by redoing the throttle relearn procedure. Unfortunately, that can only be done at a dealer, but you can at least drive there with the stock PCM, and then do a quick swap.

Generally, once the throttle relearn is done, it never has to be redone unless you mess with the throttle pedal assembly (as in, you replace the entire assembly), or the throttle bodies (again, you swap in new throttle bodies).

[Jack2o]

While unlikely, it is possible.

Given the codes and the fact that it went into limp mode (P2104), I'd start by redoing the throttle relearn procedure. Unfortunately, that can only be done at a dealer, but you can at least drive there with the stock PCM, and then do a quick swap.

Generally, once the throttle relearn is done, it never has to be redone unless you mess with the throttle pedal assembly (as in, you replace the entire assembly), or the throttle bodies (again, you swap in new throttle bodies).


No haven’t touched it all I did was remove the battery.
Prior to This the car was perfect with no issues. Do you know any reputable dealers in SoCal that can fix this?

[Jack2o]

Also noticed another thing this morning she is running rich with the arrow PCM

[Jack2o]

Quickster2 what I meant was it seems like my arrow pcm got reset somehow from the battery not being installed for that 6 months.

[Jack B]

What are the signs it is running rich



Also noticed another thing this morning she is running rich with the arrow PCM

[Jack2o]

What are the signs it is running rich

Strong fuel smell and rough engine idle with the arrow PCM.

[Arizona Vipers]

Strong fuel smell and rough engine idle with the arrow PCM.

If you really think it's the PCM, you can send it back to Prefix and they'll reflash it. I'm sure Scot Rickord will chime in here

[Scot@Prefix]

Disconnecting the battery for six months, will cause the throttle pedal sync to go by by.
Hooking back up a battery, can cause multiple codes.
Best bet would of been to keep the battery in the car and put a battery tender on it.

[Steve M]

Disconnecting the battery for six months, will cause the throttle pedal sync to go by by.
Hooking back up a battery, can cause multiple codes.
Best bet would of been to keep the battery in the car and put a battery tender on it.

Where is the throttle pedal sync stored? I wouldn't think that would end up in volatile memory...seems like a pretty big oversight if that's the case.

[Arizona Vipers]

Where is the throttle pedal sync stored? I wouldn't think that would end up in volatile memory...seems like a pretty big oversight if that's the case.

The dealer has to do it

[Steve M]

The dealer has to do it

Correct, but not my point.

Once the throttle pedal relearn is done, that information is stored somewhere. Being that it is a critical component of the vehicle's basic ability to function, I'd hope that it would be stored in memory somewhere that wouldn't be affected by removing the battery.

[13COBRA]

I agree with Steve.

I'm curious and questioning whether it needs a throttle relearn. Low voltage will wreak havoc on the newer cars. It wouldn't surprise me at all, if you cleared the codes and put a new battery in it, that you wouldn't see another issue.

[Steve M]

I guess the part that gets me is that he swapped back in the stock PCM, and it ran fine minus the one code.

An owner with both the stock PCM and Arrow PCM has the ability to swap them back and forth at will. It's not like you have to keep the one you remove on a battery to retain its memory - you can swap it right back in, and it should work just like it did before you pulled it out. That tells me that the throttle pedal sync is stored in non-volatile memory - otherwise, you'd have to reaccomplish it literally every single time you swapped, and I've never heard of owners having to do that.

Unless there's something fundamentally different about the Arrow PCM. My understanding is that it uses the same OEM hardware, just different software.

[TA Two Oh]

Subscribed. I've had both PCM's sit for well over a year at a time. And my car typically sits with the battery disconnected, also for long periods of time; I have several tenders but with the Viper, removing the negative lead is the easiest way to store the car. No issues so far but if the six month thing could be an issue then I'll change my procedure. Right now, I have three cars on tenders and the Viper has the lead pulled.

[mjorgensen]

Check the pin connectors on the Arrow PCM to make sure everything is contacting correctly possibly there is an issue, double check connectors fully snap. The rich smell could be just excess fuel from limp mode coating the cats. Scot could check functionality of the PCM, things can go bad, but it is probably rare.

[Scot@Prefix]

Correct, but not my point.

Once the throttle pedal relearn is done, that information is stored somewhere. Being that it is a critical component of the vehicle's basic ability to function, I'd hope that it would be stored in memory somewhere that wouldn't be affected by removing the battery.

It will keep it for awhile, but not forever, its in the same memory as codes, and adaptives.

Even if you drive it everyday it can lose sync and be off. You should have it done every now and then.

We have a run stand at the shop for testing various things and when the battery gets low, it will cause weird things to happen.