map sensor problem

gusset · 05-15-2008, 02:30 PM

wonder if anyone can help me my a4 1.9 tdi 110bhp goes into limp mode when i accelerate generally when in third gear this is very scary i have checked all the pipes around the turbo area and going into the ecu and they all seem to be fine-when it was put on diagnostics it showed (mapp high pressure fault) just wondering if this has happened to anybody hope i can rectify problem cant really afford audi service prices at the moment cheers

Mawhitey · 05-18-2008, 11:20 AM

I think the MAP sensor is in the ECU on the early TDi engines, i will try to find the post and report back

ini · 05-19-2008, 07:54 AM

If you have 'overboost' limp mode, it is most likely your VNT mechanism sticking (turbo variable geometry/internal wastegate)

The moving vanes/ring get jammed up with crud and stop pivoting smoothly, if the mechanism 'catches' or sticks for a few seconds, your MAP will register an overboost (or underboost).

A good long run carrying a lot of weight can temporarily cure the problem (high turbo heat), but generally cleaning the turbo, either chemically or by physically dismantling will solve the problem.

If you take the problem to a dealer, they will simply try and replace the complete turbo unit, as they do not class the turbo as a serviceable item.

Other areas to look at are MAF, vac control leaks etc etc, all the usual 'limp mode' suspects, these will however generally cause underboost fault codes.

gusset · 05-20-2008, 01:37 AM

thanks ini--i will try and clean the turbo or perhaps let a good fitter i know take a look i willl let you know how i get on once again thanks for your help and sharing your knowlege --cheers gusset

05-15-2008, 02:30 PM	#1 (permalink)
gusset Newbie Join Date: Jul 2007 Posts: 4 Gallery: (0)	map sensor problem wonder if anyone can help me my a4 1.9 tdi 110bhp goes into limp mode when i accelerate generally when in third gear this is very scary i have checked all the pipes around the turbo area and going into the ecu and they all seem to be fine-when it was put on diagnostics it showed (mapp high pressure fault) just wondering if this has happened to anybody hope i can rectify problem cant really afford audi service prices at the moment cheers

05-18-2008, 11:20 AM	#2 (permalink)
Mawhitey Member Join Date: Oct 2006 Posts: 31 Gallery: (0)	I think the MAP sensor is in the ECU on the early TDi engines, i will try to find the post and report back __________________ 1.8t conversion : Ko4-15 : Vmaxx Coils : 6 Speed 'Box : SPEC Stage 3 Clutch : S4 Heated Leather : Facelift Console and Shiney paint

05-20-2008, 01:37 AM	#4 (permalink)
gusset Newbie Join Date: Jul 2007 Posts: 4 Gallery: (0)	map sensor problem thanks ini--i will try and clean the turbo or perhaps let a good fitter i know take a look i willl let you know how i get on once again thanks for your help and sharing your knowlege --cheers gusset

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05-19-2008, 07:54 AM	#3 (permalink)
ini Full Member Join Date: Apr 2007 Posts: 98 Gallery: (0)	If you have 'overboost' limp mode, it is most likely your VNT mechanism sticking (turbo variable geometry/internal wastegate) The moving vanes/ring get jammed up with crud and stop pivoting smoothly, if the mechanism 'catches' or sticks for a few seconds, your MAP will register an overboost (or underboost). A good long run carrying a lot of weight can temporarily cure the problem (high turbo heat), but generally cleaning the turbo, either chemically or by physically dismantling will solve the problem. If you take the problem to a dealer, they will simply try and replace the complete turbo unit, as they do not class the turbo as a serviceable item. Other areas to look at are MAF, vac control leaks etc etc, all the usual 'limp mode' suspects, these will however generally cause underboost fault codes.

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