(T) MAP sensor fault - but it isn't? [throttle body clean]

Right had fault code p105 map/baro circuit malfunction fault come up...

fitted new map and it still does it...

cleaned out inlet manifold and it still does it

what happens is after the engine fault code comes up the car eill not hold a steady idle... it will run but as soon as you let of the throttle to idle it will hunt and bonce from 650-1000rmp then die...

as soon as you reset the fault codes it runs perfect.. untill it kicks off again.. which can be anything frrom ten mins later to 48 hours later....


any ideas...???

What's the full story? Why did you change the MAP in the first place, because this fault code came up? Remember a fault code just tells you the item is producing an out of limits reading, not that it needs replacing.
What engine is it?
Fault codes come with 4 numbers so I assume it's P0105?

I'm thinking there was nothing wrong with the first MAP and nothing wrong with the 2nd

What does it run like if you disconnect the MAP completely, ignoring the warnings? It should tickover fine

Crank position sensor!

did you have the software update for the throttle body flashed by your dealer?
the old software can also generate this fault code.

not as yet, thats then next situ... but cant see how the car running fine for 4 years then all of a sudden doing this causing it to play up...

with map disconnected it bitches a bit then settles down... but at idle floats once connected... , for some reason it has a very slight burnt rubbery smell comming from under the bonnet once running.. so all covers and leads are comming off tonight..., its deffo an electrical burning smell. since i work with electrics all day.. know then smell..

its a strange one.. because every time you reset the fault codes it runs spot on...

Crank position sensor mate - it's an electrical sensor.

crank sensor would show up on autel... not as baro/map..

Xila may be onto something there steely, as its the insulation that breaks down on the crank sensor with the heat over time.
It may be the insulation on another sensor that has degraded.

Does it drive smoothly or is it just tick over that's iffy

its hard to say.. it does seem to have a few flat spots now and then.. going to get her up in the air tonight to have a good look... i am wondering if the burnin smell is comming from the fan connections.. as i know its a common fault.. might have a domino effect to the electrics.. might disconnect batt for 2 hours in the process aswell just to see if it helps...

will have a good look at the Crank sensor.. but last time i looked which was 2-3 weeks ago at the time i changed oil and filter it looked mint..

But surely if its a sensor problem, why does it clear itself when the fault code is reset Ive seen it 1st hand, its very strange......

When i changed mine, it looked exactly like the new one just a bit dirtier.

I can only talk about the crank sensor and no expert but it's the heat that builds up and would suddenly cause the problem. If it was cold and only doing short journeys then you wouldn't know you had a problem, it was only on a longer run, in my case always half way to work approx 20 miles that the bloody thing would give up the ghost until cooled off then fine again.

however the symptoms i had were started like a misfire which progressed to complete cutting out and non start.

It would really help if we knew what engine it was. Hint hint
Was it actually fault code P0105?
Have you done any mods to the air inlet?

sorry bout that....

gsr induction, and powerflow exhaust... its a 1.6 16v, and it was p0105,

Ok you haven't really got a crank sensor then, but same type of animal, just an rpm sensor. That will give the same effects as Minimad has experienced ie misfire and sudden not starting which is not your problems at the moment. Rpm sensors seem much more reliable than the crank sensors as they're not buried in the engine

Your MAP sensor also has an integral air temp sensor. Are you able to read the MAP sensor and engine inlet air temp outputs?
Are you able to read the lambda sensor outputs?
Haven't done any mods to the inlet air temp sensor have you?

no. the reader isnt capable of reading live data from the stilo, the engine is bog standard barring zorst and induction... i had the same problem about 9 months back ang give the throttle body a real good clean out sorted it,,

am i right in saying the map contols idle too??? as in the same a mechanical air control valve would, ie.. sending data to the ecu to tell the throttle body how to keep steady idle...


i wouldnt say its hunting as such as in bad fuel/air mix... more just wont hold a steady idle then bounces and stalls...

drove to and from work today with no fault comming up and just a very slight murmur on the idle...