I'm trying to figure out a Haltech E8 map sensor problem. The car is off and is reading 20 PSi (3 bar sensor). Adding pressure at the sensor does not change the reading. I tested the wires to make sure everything is OK. The 5 volt is in the correct place and the map sensor will output 1.5 volts (0 PSi) when disconnected from the ECU signal line. But testing the signal line from the ECU, for some reason 3.85 volts is coming from the ECU on the signal line which shouldn't have any voltage. Anyone have any ideas?

thewird

 

Also jumping the ECU signal line and the 5volt will make the ECU read 30 PSi which it should. I just don't get why the ECU is outputting 3.85 volts on the signal line that should be dead.

thewird

 

Unplug the harness connector and check for any continuity between that pin and any 5 volt signal pins. Something might be making contact. Who wired it up?

Since when do you have a Haltech man?

 

The signal line coming from the ECU is outputting 3.85 volts at the Haltech harness (new). The map sensor is outputting a correct voltage based off correct pressure which is 1.5 volts just reading atmosphere. The ECU isn't mine. We're now talking to Haltech and they think something is actually wrong with the ECU.

thewird

 

he's talking about my car and my ECU

terrible...
thanks for the help marco

 

Ahh, yeah if the voltage is outputting directly out of the box, then there's a problem inside