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AEM SOLVED: AEM computer and MAP sensor problems

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Swoopkev

15+ Year Contributor
64
0
Mar 20, 2008
Jacksonville, North_Carolina
Running a 1990 GSX. Recently had issues stemming from wiring.
Cleaned up the wiring By cutting all the brittle wires and re-soldering new or cutting them short if unused.
AEM 1 Series EMS short circuits causing damage MAP sensor stops working, EMS is sent in to "Streetlightz" and repaired, sent back.

Findings were damaged Sensor ground.

Cool, got it fixed. Now I should be able to boost once more.

Not the Case, showing steady .033V in the AEMPro Window.
Okay, So I test the connections, wiring, check to make sure I don't have a bad sensor ground.


At this point in time Im seeing a continuity between sensor ground and ground.

Can someone verify if Sensor ground and ground should have continuity using a voltmeter?

Verified good connection between sensor and ECU plug
Verified good 5v at the MAP sensor
Verified good sensor ground circuit, no shorts

So I decided I would disconnect the signal wire, and test the difference between that and signal ground.
Aha! 1.56V is what I get.
So leaving the multi-meter in-place I reconnect the signal wire to the ECU (so at this point im tapping into the wire) -- What do I get? .33V again.

Now, I don't know much about electronics but wouldn't that mean my ECU is bad at this point?
How else would the voltage drop from being plugged in?

I'm basically at the end of my problem solving process because I've verified this sensor as working, I have nothing else I know to do, and I am thinking the problem is the AEM EMS still.

TL;DR:

Why would my MAP sensor signal read 1.56 and fluctuate with vaccuum when only the signal wire is disconnected, and immediately read .33 and not fluctuate once reconnected?
 

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Will be up first thing tomorrow morning to respond to this thread.
 
Ok. Should pins 17 and 24 on the ecu have connection with ecu ground pin 106 when tested with the multimeter?

Should chassis ground connect to sensor ground through ecu?


EDIT:
Confirmed, should have continuity.
 
Last edited:
SOLVED:

Problem was bad MAP sensor that somehow read close to good until you hooked it up to the EMS.
Replace with brand new AEM 3.5 Bar and all is well once more.
 
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