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brownjeff, ASE Certified Technician
Category: Jeep
Satisfied Customers: 13886
Experience:  17 years experience, ASE certified, dealership certified, Service Manager for 15 years,
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2000 Jeep Grand Cherokee: Oil change..flush..Control Module..the PCM

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2000 Jeep Grand Cherokee Ltd - Turned in to Jeep dealer for routine maintenance - Lube & Oil change, check fluid levels for flush and replace, and run diagnostics for any other problem.

Diagnostic check revealed a code P0601 Internal Control Module Memory Check Sum Error.

Service manager called to ask permission to replace the PCM for nearly $1000. When we asked him to determine what the problem was that caused the error code 0601, they did not know.

Asked if it was necessary to replace the entire unit with first determining the causal factors for failure of the PCM --advisory being that simply replacing the PCM may not cure the problem or that it will reoccur in the near future?
Hello and Welcome to JustAnswer,

My name is XXXXX XXXXX I am here to try and assist your with your question. The code 601 in an internal failure in the powertrain control module (PCM). The only fix is to replace the PCM. There is not a test to do for this as the cause for this code is the PCM itself and another component doesn't cause this failure. Simply put the PCM has failed and needs replaced
brownjeff and 2 other Jeep Specialists are ready to help you
Customer: replied 6 years ago.

Vehicle is out of routine maintenance available for pickup. Assume we can pick up and then return it to Jeep Service next week for PCM replacement with no problems. Engine is running fine. Service saw no problem with driving it for a few days longer. They would have to order the part anyway.


Is this OK or, is it a problem driving it with a PCM code P0601 indicated?

it will be fine to drive until they get the part.

Edited by brownjeff on 10/29/2010 at 4:01 PM EST
Customer: replied 6 years ago.

But since vehicle has been running OK since dealership first detected problem at least 6 months or more ago, what COULD happen if we don't repair and keep driving?


Also, found answers on your site and other advice sites that sensors or short circuits really could be cause sometimes when peope are advised to replace PCM and replacement doesn't solve problem. Are you saying that trouble code 601 rules out that possibility? Thank you,

You may not have any issues with the way the vehicle runs. Will be a problem though when trying to get an emissions test done and the check engine light is on. If a sensor was shorted or wiring there would be other codes and other problems with the vehicle
Customer: replied 6 years ago.
So it is OK to drive as is? It won't suddenly stall for the PCM reason? Our state does not have emissions tests.
Yes ok to drive as is and if running fine may want to wait on the repair
Customer: replied 6 years ago.
Thanks, Jeff. That's what I wanted to know.
No worries......

Take Care