2002 jeep grand Cherokee code P0601 service engine light?

Answer 1

This code means: "Internal Control Module Memory Check Sum Error"

Basically the PCM (your computer) has a problem that should be addressed.

Sometimes there is no change in performance, sometimes it will idle roughm and stalls....

The PCM is expensive to change at the dealer, usually $500-600, the problem is after they install a new one, they have to reprogram it.

Here's the better news. Try rebooting your PCM, this is how.

Disconnect your Batt cable, then press down your brake pedal to activate the brake lights for 1 minute (this drains all the power), reconnect, start truck and go. It may run rough for a while until it relearns itself (20 miles + 12 starts)....

If this doesnt work, go to ebay, you can get reconditioned ones there, preprogrammed for your vehicle, easy to install for around $199. you send back your old one. They also offer lifetime warrantys.