like the title says ..for some reason the signal is making its way through the ecu...tripping it out and making the car think that it is at 10.4 lbs at all times I've checked and added grounds,checked and replaced map sensors and ecu's but none of that is the problem.somewhere there is a voltage short but it is only effecting the map sensor...any insight on this will be greatly appreciated..until then my 400hp beast sleeps

 

First of all, what car, what engine, what map sensor if it is not stock, and what ECU and if it is chipped or not

So one pin on the map sensor is getting 4.7 volts all the time, and what about the ground pin, does that get a good chassis ground?

Also, attached is the troubleshooting guide for map sensors for 92-95 civics, it should be similar for a teg as well. Its a starting point that might help.

 

92 civic dx
Gsr engine and hondata s300 gsr ecu
I had a gm 3 bar installed but swapped back to stock the simplify the process.the sensor voltage is where it should be and the groundalso checks out..when I get home I'm going to use a better meter and get some more numbers..thanks for the guide

 

check continuity of the wire from your ecu to the MAP connector. If continuity exists, then you likely have a bad ECU. If there is no continuity, then you obviously have a open circuit in the return signal wire.

Open circuit on the return side of the sensor WILL cause it to see full 5V.

Was the car ever running on this exact setup?

 

The map should read 4.7v koeo. That is atmospheric pressure and is a normal reading koeo. Are you saying that you are also seeing this reading with the key off?

 

The car was running with a 3 bar map, perfectly fine, was driving it across the causeway bridge in New Orleans and before I could get across the voltage changed like so causing it to run like crap. Had my laptop on me ..adjusted the values and got it home limping...the reading is on the signal side, not the constant and it is coming from the ecu..no matter what ecu or map I use. I'm going to swap the engine harness this afternoon .thanks again for any suggestions