Hello all, usually between my manual and searching here I can fix my problems with my 1999 4.0 Grand Cherokee. Not this time. My GC has 192000 miles and has been faithful. I went to start it, and slow to start then die right away. Searching here it sounded like the idle air control valve was bad. Replaced that and no help. The check engine light then came on then. I bought a code reader and it read 'PO106, Generic stored. Map circuit range/performance problem'. So I replaced the map sensor. Now it will still start hard and Idle after a little feathering with the throttle. I do not see the PO106 code in my manual. It shows PO107 low voltage and PO108 voltage to high to map sensor. So then I read to clear the code before starting, apperantly so the computer is not confused. My code reader has that ability but the code did not clear. I am not sure how to manually clear the code or if that stored code is part of my problem. Maybe the crank sensor, not sure, I hate just throwing parts on in an attempt to repair something. Sorry about the long post but I wanted to be some what clear to whats happening. Thanks for ANY advice, I am stumped. Take care, Mike.

 

If you disconnect the battery cables and touch them together and re install them the codes will clear. However unless there is something real serious you will have to drive it about 80 miles before it will show codes again

 

Voltage high to MAP sensor. Find out what that means. IT should have +5, sensor ground, and sensor signal. What does the MAP read in vacuum on your code scanner? 10 to 12 is somewhere in the range. If its way out of that there’s another problem. hope that heps

 

Well, after about an hour typing my problems I have to apolagize. I made a huge mistake. Some of the older members here might understand. Go a head and laugh, I deserve it. First off I have to thank 4.3L XJ for the tip on how to clear the codes. Thank you. Second of all I wish I could kick myself in the ash can. I will explain and you will probably be lining up to kick me as well. After I used 4.3L XJ advise on clearing the codes I plugged in the code reader. I could see some info running behind the screen under the original Map problem. I put my cheater glasses on and saw a tiny plastic cover over the screen. A generic code to help sell the code reader. DOH! I peeled the tiny screen protector off and things cleared up pretty good. Unfortunatly the check engine light was not on and no codes were found. Man, do I feel STUPID! Sorry for the mistake, back to square 1. P.S. I wish everything was as simple as my old ****** wagon. Thanks, Mike.

 

Thanks 97grand4.0. Unsure were I am at now, take care, Mike.

 

After all that, it turned out to be the pressure regulater in the filter. Thanks, Mike.

 

Glad you got it sorted out