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Inspect vacuum lines at MAP sensor and at Throttle Body. Repair as needed.

WHEN TESTING THE MAP SENSOR, ENSURE THAT THE HARNESS WIRES ARE NOT DAMAGED BY THE TEST METER PROBES.

Test the MAP Sensor output voltage at the MAP Sensor connector terminal B (as marked on the sensor body). This is done with the ignition switch ON and the engine OFF. Output voltage should be 4-5 volts.​
The voltage should drop to 1.5-2.1 volts with a hot, neutral idle speed condition.
Test engine controller (terminal 5) for the same voltage as described above to verify the wire harness condition. Repair as necessary.​
Test MAP Sensor supply voltage at sensor connector (terminal C) with the ignition ON. The voltage should be approximately 5V (+/- 0.5V). 5V (+/- 0.5V) should also be at terminal 6 of the engine controller wire harness connector.​
Test the MAP Sensor ground circuit at the sensor connector (terminal A) and the engine controller connector (terminal 4).​
Test the MAP Sensor ground circuit at the engine controller connector between terminal 4 and terminal 11 with an ohmmeter. If the ohmmeter indicates an open circuit, inspect for a defective sensor ground connection. This connection is located on the right side of the cylinder block, at the oil dipstick tube mounting stud. If the ground connection is good, replace the engine controller. If terminal 4 has a short circuit to 12V, correct this condition before replacing the engine controller.​
 

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Why, you're quite welcome kind sir...

<~ had to reach down for the Southern accent for that one...:D
 

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That you for posting this, just what I was looking for.



Inspect vacuum lines at MAP sensor and at Throttle Body. Repair as needed.

WHEN TESTING THE MAP SENSOR, ENSURE THAT THE HARNESS WIRES ARE NOT DAMAGED BY THE TEST METER PROBES.

Test the MAP Sensor output voltage at the MAP Sensor connector terminal B (as marked on the sensor body). This is done with the ignition switch ON and the engine OFF. Output voltage should be 4-5 volts.​
The voltage should drop to 1.5-2.1 volts with a hot, neutral idle speed condition.
Test engine controller (terminal 5) for the same voltage as described above to verify the wire harness condition. Repair as necessary.​
Test MAP Sensor supply voltage at sensor connector (terminal C) with the ignition ON. The voltage should be approximately 5V (+/- 0.5V). 5V (+/- 0.5V) should also be at terminal 6 of the engine controller wire harness connector.​
Test the MAP Sensor ground circuit at the sensor connector (terminal A) and the engine controller connector (terminal 4).​
Test the MAP Sensor ground circuit at the engine controller connector between terminal 4 and terminal 11 with an ohmmeter. If the ohmmeter indicates an open circuit, inspect for a defective sensor ground connection. This connection is located on the right side of the cylinder block, at the oil dipstick tube mounting stud. If the ground connection is good, replace the cars engine controller. If terminal 4 has a short tires circuit to 12V, correct this condition before replacing the engine controller.​
 

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00 jeep cherokee

wher is the map sensor located on a 2000 jeep cherokee xj 4.0 check engine light reads code p1296 which is map sensor any help?
 

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:brickwall: Mine had a hesitation, idled at 1100RPM and threw codes "12" ,"13" and of course "55".

:( It was a vacuum line melted closed by the intake manifold, that one that runs up to the MAPsensor.

:D Snipped off the damaged part, being in the last 1/2 inch of line, and reconnected. No more problem; no more codes. Neutral idle is @ 900RPM again.

:thumbsup: Excellent write-up, Bowtieguy3. thank you for including the drop in reference voltage (5v to 1.5-2.1v)
 

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I normally unplug mine. If there's no change it's bad. :rofl:

Nah, nice write up and good info. I'll be keeping this for future reference I'm sure. :thumbsup:
 

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i normally unplug mine. If there's no change it's bad. :rofl:

Nah, nice write up and good info. I'll be keeping this for future reference i'm sure. :thumbsup:
lol mee too
 

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Great Write-up!
 

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Thanks for the writeup!

I have been having some hesitation when it's warm outside -- mostly in the range of 900-1300 RPM, and mostly when accelerating, but also when idling. I tested the map sensor per your guidance above. The A to B test (ignition to ACC position, engine OFF) showed about 3.6v. A to B with engine ON and idling showed around 1.19 to 1.21v. Is this far enough out of range that it's causing my problem?
 

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Arrgh. After reading the correct 5v from A to C with engine off, and a low 3.6v from the old MAP sensor (from A to B, engine off but in ACC mode), I installed a new MAP sensor. No dice. I still have 3.6v between A and B with engine off. Does this suggest a bad ground associated with the MAP sensor? I tested the TPS, and looks like there is slightly less than 5v going to that (4.2, or so). I really don't know where to go from here.
 

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Arrgh. After reading the correct 5v from A to C with engine off, and a low 3.6v from the old MAP sensor (from A to B, engine off but in ACC mode), I installed a new MAP sensor. No dice. I still have 3.6v between A and B with engine off. Does this suggest a bad ground associated with the MAP sensor? I tested the TPS, and looks like there is slightly less than 5v going to that (4.2, or so). I really don't know where to go from here.
BY the way, I"m not getting any codes or check engine light (other than getting 12 for battery disconnect).
 
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