Anyone ever seen a "stuck" MAP sensor?

devonutopia

Top Post Dawg
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Dec 1, 2003
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Devon, U.K
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PD300 Skoda Fabia
Just ran a log on a remapped (stage 1 I believe) Golf mk4 (PD150) and I've never seen this before. The actual reading on group 11 for the boost was 2480 when static. It read 2480 until the momentary time that the boost was coming over this threshold for a brief moment, and then once cruising again - specified boost around 1100 to 1200 as expected, actual 2480 and not moving one little bit.

Can they stick? No faults for the sensor either! :confused:
 

DPM

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Mar 16, 2001
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Newtownards, N. Ireland
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2019 Rav4 AWD Hybrid, Citroen C4 BlueHDI
well assuming it's not some artefact of the remap, it could be pneumatic (blocked sensor port), electrical (wiring), or electronic (dodgy sensor). Eyes and hands on methinks.
 

devonutopia

Top Post Dawg
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Dec 1, 2003
Location
Devon, U.K
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PD300 Skoda Fabia
Well, the wiring was found to be a little suspect, but conductivity appeared unaffected. I said to get the wiring A1, and I would hook it up to VCDS again.
 

JFettig

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I hear that the Jeep Liberty CRD's we have here get clogged up, not sure what the effects are. Is it in an easy position to swap it out quick?
 

ArturCosta

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Dec 8, 2003
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Portugal
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Audi A4 Avant 1996 Silver
I once had a stock A4 130 tdi with that problem. MAP was always reading more less 2500mbar.
We changed the map did not even try to clean it.
 

Kevinski4

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Aug 31, 2007
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Nebraska
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'00 ALH Jetta GLS
I had one last week that was stuck at 2300 and would only read the little blip of a boost spike over that level, then go back to reading 2300. Replaced the sensor and everything was back to normal.
 

devonutopia

Top Post Dawg
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Dec 1, 2003
Location
Devon, U.K
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PD300 Skoda Fabia
it does seem the sensor is to blame. Thanks everyone. A new one is being fitted on Friday (as long as it arrives in the post) then I shall hook up to VCDS again. All being well this will cure the symptoms being suffered.
 

devonutopia

Top Post Dawg
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Location
Devon, U.K
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PD300 Skoda Fabia
Quickly bumping this one as had another weird one, same symptom - an apparent jammed MAP sensor reading 2193 on idle, however when a brand new OEM map sensor fitted it was reading exactly the same thing.

So what can be causing this? Do I need to start recommending looking at wiring etc?

The car is a 2006 Skoda Octavia with the PD105 1.9 engine. :)
 

devonutopia

Top Post Dawg
Joined
Dec 1, 2003
Location
Devon, U.K
TDI
PD300 Skoda Fabia
brand new perhaps, but known good?
I would normally have been suspicious of an Ebay brand new item, but with both sensors giving the same readout (or the car saying the same reading) I have to assume both sensors are OK and it's the car which is reading the outputs wrong and translating it to 2193mbar. On the PD105 engine I am not sure if 2193mbar is max boost for the sensor.

Have a feeling it could be wiring related as apparently someone else had similar and it turned out to be a dodgy connection of the MAP sensor wiring behind the N/S headlight.
 

Dorkage

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Aug 27, 2010
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Thunder Bay, ON, Canada
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2003 Wagon TDI, 2004 Golf R32
Make sure there isn't corrosion or anything like that in the connector for the MAP. My understanding is they just output a certain voltage for a given pressure, so if there is some corrosion current could be going thru it and causing the ECU to see pressure when there isn't any.
 

JFettig

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Aug 18, 2010
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Blaine, MN
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B5 Passat, 2010 Jetta
We are seeing exactly the same thing on a local BEW car(EDC16), we did some diagnosis and couldn't get it to budge +/- 2193mbar It has a 3bar MAP.

We probed the wires, swapped ecus, all seemed normal. We saw a little extra resistance in the ground but nothing out of the ordinary. We are guessing its cross-talk somewhere or something.
 

ryanp

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usually a fault with some other wiring, Lambda, N18 etc giving the wrong ref voltage, does not have to be the MAP wires with the fault :)
 

jptbay

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Aug 9, 2007
Location
Thunder Bay
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2003 Beetle, 2006 Jetta Wagon
Currently plagued with this.

Tuned BEW with 3 Bar map. Map went bad 2 years ago. VCDS reading stuck at 2193 mbar. Replaced MAP and problem fixed.

Now, same symptoms. Replaced MAP again with new unit, but VCDS reading still reports 2193 mbar. Group 22 Shut-off status shows 002 system malfunction.

I took a general look at a bunch of the engine harness and saw nothing obvious, including pulling the wires out of the MAP harness loom from the plug up to about the coolant bottle. Again nothing obvious.

Going to de-pin the MAP connector plug and take a look at the pins next.

Anyone experience this and find a wiring harness issue somewhere?

Thanks.
 
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