2002 Volkswagen Bora ( jetta ) - tdi 130 map sensor wiring fault?

Honest John Back Room » Technical matters
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
View Threaded
Tue 10 Sep 2013 22:22
2002 Volkswagen Bora ( jetta ) - tdi 130 map sensor wiring fault? - boratdi

Hi,

i previously made this topic about the problems i have been having
http://www.honestjohn.co.uk/forum/post/index.htm?t=102208#m110105

Now i'm thinking i might have a wiring fault as i have been making the car underboost ( no boost ) and over boost to around 2800Mbar ( 28psi? ) and stock mbar is 2346.

I have not had any faults reported in VCDS.

I took the voltages from the map sensor plug.

Pin 1 i belive is ground
Pin two 4.99
Pin three 4.99
Pin four i get 0.1

Could someone PLEASE shead some light on this. does the map sensor actualy report back to the ecu to let it know theres to much boost?

Reply | Report as offensive | Link
Wed 11 Sep 2013 11:11
2002 Volkswagen Bora ( jetta ) - tdi 130 map sensor wiring fault? - dieselnut

The MAP sensor tells the ECU what the air pressure is in the manifold. It may also have a temperature sensor built in to it as well. The ECU uses this info together with other sensors to control fueling & turbo boost pressure. If you've got VCDS you should be able to record actual boost against required boost while driving. The common problem on these engines is that the turbo boost control mechanism gets clogged with exhaust particles & eventually jams in the full boost position. This leads to overboost & reduced power imposed by the ECU to avoid engine damage.

Reply | Report as offensive | Link
Wed 11 Sep 2013 15:39
2002 Volkswagen Bora ( jetta ) - tdi 130 map sensor wiring fault? - cws

As per dieselnut's advice, VCDS should be able to tell you if the MAP is performing as it should, via one of the graphs showing expected output/actual output.

Reading your previous post, you say you've removed the EGR (and N18 valve) and the valve/solenoid that controls anti-shudder? In your position, the first thing I would do would be to put the engine back to exactly how it was as factory-standard ie put the EGR valve back etc. You can't say with 100% certainty that not having these original parts in place are not a contributing factor, even though the engine may have run fine for ages minus them.

Reply | Report as offensive | Link

Looking for a garage you can trust? Honest John's Good Garage Guide has thousands of reader recommended garages, plus how-to guides and tips on servicing.

The Good Garage Guide