Dealer coded the computer and said it was a bad MAP and IAC. Got parts FED EX'd to house and installed. Tried to clear codes with scan tool but they wont clear. HELP, 45 driveways to plow and it's snowing!!!! 8 to 18" expected.... this will cost me a fortune!!!

 

Got the code to clear... for ten seconds. Truck is in safe mode, no *****, no boost over 5#, no more than 30mph. Idles great!!! I changed the fuel filter (couldn't hurt, right?) and found out that when the truck is COLD, it runs ok. Some bucking but has power. After it warms up, bucks a few times and goes to safe again. WHAT IS THIS????? Any ideas folks? I'm stumped.

 

I think the 5 volt supply for the MAP comes from the ECM. You should take a voltmeter and check for 5 volt at the MAP sensor first. You did not list codes which would have helped. Good Luck

 

Generaly low voltage bad ground , no voltage no power.


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12-93 2500 4x4 auto cummins from this site 2 wks ago $7500. clean , love it.

 

checked both sensors, theyre good, wireing good, ECM is shot. Went into Safe/Limp mode. Have to get a new one today. Mopar Performance Parts Cat lists a Hi-Perf one, have to see if they can get that, although it may just be the stock HO in disguise. Thanks to those that replied....Chris