# Motronic 2.9 ECU Pin 33 and 54



## Vanagon Nut (Oct 19, 2007)

Hey folks.

So this Jetta 2.0 is in a Vanagon. It has run ok for thousands of miles but has had a few consistent minor issues. 

I went through the harness, again, using several different versions of wiring diagram. I found:

No ground to ECU 33. ("sensors ground") This has been corrected. Associated sensors were connected to ground however.
VOM on ECU 1 and 54, no power, ign. off. I may have wired it to the 15 buss. Ran out of daylight to check.

What exactly does the ground to ECU 33 do?
What difference will it make if I wire ECU 54 to B+ (constant power)?

Thanks. Neil.


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## Vanagon Nut (Oct 19, 2007)

Yup.

Oops. 

Still ran ok. Will be curious if this cures the hot start issue and hunt for idle on hot days, engine hot. (always suspected the IAC system as culprit. Bentley says it's an adaptive system that recalls settings when engine shut OFF.  )


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