I have a 2001 5.2 with an auto tranny. I just had the transmision rebuilt and it is now throwing a code. Actually it was throwing a code before the trans was rebuilt. I'm now being told the problem is the computer and it needs to be replaced but I don't want to spend or have $700 for one. They said only the dealer can do it, they can't find a remaned unit available for my truck. They also said it only has one computer, not two like some vehicles. Can I get a computer from a junkyard instead? If I have to spend $700 is there and aftermarket computer that has already been programmed to give me better performance available? Thanks in advance.

 

i had to get a new PCM for mine, went to the boneyard and picked one for 175 and it works fine. A few tweaks that Hemifever will take care of when i order my SCT

 

Do you know what codes its throwing? Post them up here and we'll be able to help more...

If you did have to get another computer, it would have to be from the same year/engine/trans as yours. We don't see a whole lot of failed pcms here, usually there is another issue causing people to think the computer is shot... get those codes and we'll know more about what's going on with it

welcome to df

 

It's showing P0601 PCM Internal Ctrller Failure. Is there anything I need to know beside year, engine and trans to get a boneyard computer?

 

hmmm I did some searching and got this:

P0601....Internal Control Module Memory Check Sum Error

unfortunately, everything I found did indeed point to requiring a new PCM.... I'm not 100% sure on what requirements are needed to find a replacement other than what I mentioned, but someone will chime in that possibly knows more about it...

 

RockAuto has PCMs. They are not a dealer only item.

 

You only have one because, you do NOT have an ECU. That term (Engine Control Unit) is applicable to diesel models only.

If you've got a GAS engine, you have a PCM (Powertrain Control Module) and, it resides in the front passenger side of the firewall.

Now, you should be able to find an aftermarket model for that year. The place I used to shop is now out of business so, I don't know who's selling QUALITY units at this time.

Most of the ones out there are NOT fully tested for other failures other than the initial failure that they repaired. These companies also use lower rated / low quality replacment components thus, the reliability of the unit is questionable. It may last years or months. I've seen and heard both sides of the argument.

Now, the dealer unit is about right as it's new, it's got a HIGH REL rating, it's fully tested AND comes loaded with the right software and firmware for your year. However, THEY CHARGE the end consumer to LOAD that software / firmware onto the unit. They charge a base price of the PCM itself and an ADDITIONAL fee to load the firmware and software (OEM flash procedure)

Now, aside from that information, the real question is, what is wrong with the vehicle and, the only way to find that out is by looking up that OBD code and then start troubleshooting based on that code. Otherwise, you're flying totally blind and, I've seen MANY who drop in new PCMs only to find that the underlying root problem was not resolved.

CM

 

Oh, just saw the update to this thread after I posted above. Checksum error means MEMORY FAULT. That's a problem and, YES: time for a new PCM if it's shorted internally or, the MEMORY has gone south.

P0601 is the internal code for a dead or short internal on the serial link for communications but, there's also two other things that will PRODUCE the same symptom and same code. NOTE: there's also a way to try and SAVE IT.

Possible FIX / SAVE:

CONNECTOR TEST:

- Remove the Negative BAT terminal and wait for 30 seconds or longer.

- REMOVE all the connectors at the PCM and disconnect and reconnect two or more times.

- CLOSE all doors, turn off all ignition CKTs, remove the KEY from the ignition, radio OFF, headlights, turn signals etc- all CKTs are to be OFF.

- Reconnect the NEG (-) lead on the BAT.

RETEST:

<IF> the problem goes away - it was due to a loose connection at the PCM.

<IF> the problem does NOT go away, FLASH IT.

FLASH PROCEDURE:

You will need a flash tool to do this OR, the dealer can also do this for you for a FEE of 100.00 - 200.00.

TO FLASH IT OR TRASH IT: AFTER FLASHING

<IF> the problem goes away - it was due to a corruption in the PCM programming either firmware or software thus tripping the CHECKSUM error. It's common with computers in general and, sometimes reinstalling firmware or software will alleviate the issue if it's corruption in the software and firmware level.

<IF> the problem does NOT go away- TRASH IT. This is indicative of a hardware level failure in which case, A NEW PCM would be required.

CM

 

Thanks guys, I'll try the connector test first, I would rather take my chances on a used PCU than pay the dealer to flash it and not correct the problem.

One thing I just thought of, not to long before the code popped up I bought a superchips programmer off ebay. It turns out it had been used before so it couldn't work. I'm not worried about the programmer, I bought it from a good seller who gave me my money back but could trying the programmer have anything to do with it?

 

ABSOLUTELY YES> BAD FLASH issues! That's most likely the root cause right there. That right there, the last paragraph, is more than enough information to make an assessment without even testing the PCM.

CM