MAP sensor reading
- S_Hadley1138
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my MAP sensor always reads 2 kPa via the ODB software, even when running. is this normal? should it not fluctuate? what do others read? any help would be appreciated, as I seem to be hesitant at times when in a gear a bit too high, or cold. any help would be appreciated
by S_Hadley1138
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- S_Hadley1138
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some further investigations....... i did some tests on the cabling to the MAP sensor and discovered +5v on the cable that reports the signal back to the ECM. my conclusion is that this is a short somewhere in the loom.
Took the big plug off the ECM, to see if i could easily identify the cable, and run a separate one just for the map sensor... couldnt easily identify the cable, so decided to order a replacement wiring loom.
now here's the rub... after disturbing the cables, the car now runs like a dog. starts, then revs drop and stalls, unless you give it more gas. it can be driven, but gear changes have to be fast not to let the revs drop.
I'm pretty certain that this confirms my thoughts that there is a short circuit in the wiring loom.
Anyone else had similar?
or experience of changing the engine management wiring loom. doesn't look too difficult, but interested in hearing from others
Took the big plug off the ECM, to see if i could easily identify the cable, and run a separate one just for the map sensor... couldnt easily identify the cable, so decided to order a replacement wiring loom.
now here's the rub... after disturbing the cables, the car now runs like a dog. starts, then revs drop and stalls, unless you give it more gas. it can be driven, but gear changes have to be fast not to let the revs drop.
I'm pretty certain that this confirms my thoughts that there is a short circuit in the wiring loom.
Anyone else had similar?
or experience of changing the engine management wiring loom. doesn't look too difficult, but interested in hearing from others
by S_Hadley1138
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The wiring diagrams are in the downloads section under the Community heading, maybe that could give you some insight into what is on the circuits with the ECM?
by aj76
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- S_Hadley1138
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after some testing, I could see there was a short coming from the MAP sensor. decided to get a new loom. while disconnecting the old loom, I noticed a bent pin in the big square connector, sure enough the one from the map sensor was shorting out agains the +5v supply to the sensor. (pin 13, bent into pin 12)
. straightened the pin, reconnected. We could see a dodgy repair on the old loom too, so took the plunger and swapped it out.
BINGO!! 12 months of very ropey driving, and she's purring like a kitten...
next job, the random alarm problem.....
BINGO!! 12 months of very ropey driving, and she's purring like a kitten...
next job, the random alarm problem.....
Last Edit:1 year 5 months ago
by S_Hadley1138
Last edit: 1 year 5 months ago by S_Hadley1138.
The following user(s) said Thank You: deepfat
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