I had a short circuit problem with my car because of a faulty fuse and some of the engine harness wires melted together. I repaired the harness the engine starts normally but I am getting Signal high obd codes for the 3 MAP pressure on the engine.


The B83-II is one of the MAP sensors. I measured the voltage between PIN 1 and 3 of the sensor and i am getting mVolts instead of the 5V. I backprobed the ECU pins and i got the same voltage. The voltage between PIN 3 and battery negative is indeed 5V.

My question is , should i expect 5V between PIN 1 and 3 or PIN 1 and battery negative or both?

The engine is 1.4 TSI VW.

  • When probing these, I would think one might be 5v+ continuous (with ignition on) and the other be the signal going back to the ECU. The second would be ranging from .5-5vdc so the ECU can convert properly. If my hunch is correct, you'd want to test these by probing these on the red lead and grounding the black lead of your multimeter. Personally, I'd be testing all four leads to see what they give you. Looking at it, seems to me 1 is going to be your power, considering it splits between B83-II and B186, but that's a guess. Commented Nov 14, 2022 at 11:05
  • I am trying to understand the difference between sensor ground and battery ground, can someone point to a material to read,? I mean the sensors are getting positive negative and signal wire the voltage between positive and negative should be 5V ?
    – giannisf
    Commented Nov 16, 2022 at 11:27
  • With little info from wiring, it appears to me B83-II pin-1 and B186 pin-1 share the same connection....to ecm ground? Did you check continuity between those pin-1s and where they end? Continuity test for B83-II pins 2 and 4?
    – F Dryer
    Commented Nov 21, 2022 at 4:41


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