Question for pros ;)

[ksanturion10]

What could be the reason, except for the ECU, for the MAP 5V reference signal to be erratic and steadily go up to 6V or more?
The measurement is taken between the MAP and its plug (all is connected). My presumptions are:
1. If MAP is malfunctioning maybe somehow it does this internally (not sure how can happen);
2. 5V reference shorting to +12V???

[ksanturion10]

Solved

[Hell Razor5543]

How?

[ksanturion10]

Preffer to answer, what was the cause, as it may spare someone the 1 month battling, which inturn answers the question how .
Ofcource, there was one more possibility, as the hand made, by me, probe could be shorting also, but actually the way my question was introduced, prevents the pointing out of the real reason for the MAP's strange behaviour.
Generally the 5V reference signal is comming directly from the engine ECU and because I've checked all the related wirings, and found nothing suspicious, it seems that the ECU is starting to degrade its performance, and worst, started giving false reference signals to the connected sensors.

[GiveMeABreak]

The engine ECU doesn’t give reference signals to the sensors; the sensors give the signals to the engine ECU.

The engine ECUs are generally trouble free. It will more likely be issues from connected equipment and sensors that may be faulty that prevent the engine ECU from doing its job.

[ksanturion10]

This might be helpful: https://www.motor.com/magazine-summary/ ... -may-2016/.
But as I said, I'm pretty sure that the ECU is responsible. Maybe it only happens intermittantly.

Ofcource, sensors like Lambda, Engine Speed or Knock sensors generate their own signals, but most of the early type MAP and TPS sensors need constant reference signal.

BR
Martin