P0237 [Videotroubleshoot and Measuring Blocks Vagcom

[fastwire]

Hello everyone, I uploaded a youtube video with the readings from Vagcom in the end of this post.
(sorry my bad english and odd voice on the video)

Background:
My car has been with this fault P0237: Map signal too low.

Some search points to the MAP sensor wiring that goes bad.

When reading with Vagcom the values while engine is running,
the actual boost pressure stays steady at 980, while the requested boost pressure is at 360, If I press the gas pedal, the actual boost pressure will stay at 980 and while go up only if the rpm's are over 2k, wich looks weird, I dunno if this is normal or not.

And if I press the wiring loom that sits in top of the starter, the values will drop and the engine will stall. Help I dunno if the short is in that wiring loom, it looks but not sure can somebody chime in that knows how to read those values correctly? thanks in advance

https://youtu.be/WFSdQcmwnqY

 

[MikeG918]

I was having an issue with my old map sensor, when I changed it with a brand new one my readings were the same as yours 980. I believe 980 millibars is atmospheric pressure so that seemed right and I left it alone after that. I think that's right but I could be wrong.

 

[fastwire]

I was having an issue with my old map sensor, when I changed it with a brand new one my readings were the same as yours 980. I believe 980 millibars is atmospheric pressure so that seemed right and I left it alone after that. I think that's right but I could be wrong.

yeah thx, I just found that the correct reading is 1000 or 1040 mbar, pointing to a vacuum leak. Does anybody knows how to test a vacuum leak on this engine? I've seen smoke tests with a cigarrette but dunno how to point it on this engine. thx in advance

 

[Gruppe917]

You could easily build a pressure tester with a small handheld bike pump and a Pvc cap. Quick, cheap, easy and reliable

 

[MikeG918]

One way I did it was to spray starting fluid on hoses and monitor short term fuel trims. Kinda ghetto but it works. You'll tell when you find a leak, short term will start pulling fuel. Just keep it away from your intake.

 

[fastwire]

One way I did it was to spray starting fluid on hoses and monitor short term fuel trims. Kinda ghetto but it works. You'll tell when you find a leak, short term will start pulling fuel. Just keep it away from your intake.

thats nice. I wanna use this method. that spray is very flammable though..

just spray the fluid over the hoses and monitor short term fuel trims?

how to monitor fuel trims? thx in advance

 

[MikeG918]

thats nice. I wanna use this method. that spray is very flammable though..

just spray the fluid over the hoses and monitor short term fuel trims?

how to monitor fuel trims? thx in advance

Yes that's why short term fuel trims will change. It takes a very small amount of fluid to see the changes in fuel trims (i.e. Don't soak the engine in it, small half a second sprays aimed at the vacuum lines). When I found a few cracked lines my fuel trims dropped to -17 and when it burned off the fluid it would return to 0. It took maybe 2 seconds to see the change.

 

[fastwire]

Yes that's why short term fuel trims will change. It takes a very small amount of fluid to see the changes in fuel trims (i.e. Don't soak the engine in it, small half a second sprays aimed at the vacuum lines). When I found a few cracked lines my fuel trims dropped to -17 and when it burned off the fluid it would return to 0. It took maybe 2 seconds to see the change.

thats perfect thanks!

how can I monitor fuel trims??

 

[MikeG918]

thats perfect thanks!

how can I monitor fuel trims??

Block 32 in vag com :thumbsup:

 

[fastwire]

Block 32 in vag com :thumbsup:

thx again man

 

[GTI's]

033 for Stft 032 for Ltft

Great video that explains https://www.youtube.com/watch?v=yM3iarhSP68

 

[fastwire]

033 for Stft 032 for Ltft

Great video that explains https://www.youtube.com/watch?v=yM3iarhSP68

bingo! thanks x4