I was wondering if anyone has had a similar issue to the one I am having. I switched my car from an Omnipower 4 bar map sensor to a AEM 5 Bar Stainless Steel Map Sensor. When the sensor is connected to the harness my car will not connect to my AEM EMS. However the moment I disconnect the map sensor I can connect without any issues what so ever.

Thus far I have performed the following to troubleshoot this issue:

1) Sent EMS to AEM and they verified there was no connectivity issue with the ECU
2) Verified that the pigtail is connected correctly
*Ground connected to black wire on the harness
*5 Volt connected to the grey wire on the harness
*Signal Wire is connected to the yellow wire on the harness
3) Purchased a brand new pre-wired pigtail to make sure that it was getting a good connection.

At this point i am at a loss. My car has been down for almost a month now do to this and I am out of ideas. Have anyone had a map sensor just go bad on them?

 

The only things I could say to try next is a new AEM Map Sensor.

 

Sad thing is that it's a brand new map sensor.

 

I would double check to make sure the wires are good. wire color isn't always the best thing to go by, take a multimeter and meter from the 5 bar output, and the meter from the ecu side. If the pins are correct, you will here a beep(which will let you know your pin position is correct) if you set your meter to beep when you have continuity. Or what you can do is meter the 5 bar itself, between the power pin and either the ground pin or the signal pin and see if the 5 bar is grounded out inside the case itself. Me? I think its a bad sensor, but those 2 tests will tell you for sure.

 

Starting to sound like you maybe right. Borrowed a 3.5 bar aem sensor from a friend last night. Fuel pump relay now kicks on and boost solenoid is now starting to activate. I wasn't able to get the EMS to connect via my computer but my tuner says that it maybe an issue with the cable. He is going to come over and check things out tomorrow and see if we can't get it to fire up.

 

On an AEM EMS S1 the comms are linked to the 5v out. So if you have a sensor wired in wrong, or the cal is out of wack, it will prevent you from connecting.

First try this:
Unhook the sensor
Connect to the EMS
Select new sensor from the list
try to plug sensor back in

If that does not work try this:
Get a multi meter and verify the pinout to the sensor, make sure that +5v is going to the correct pin and that Ground is going to the correct pin


If the setup is good, and the wiring is good then you might need to test the sensor, call AEM and ask them how to verify the sensor.

I hope that helps.

 

I'm about 80% sure the 5 bar is bad. Here is why.

Plug the 5 bar sensor in and nothing. Fuel pump relay doesn't turn on, fan doesn't come on, boost solenoid is quite.

Plug the 3.5 bar sensor in and fuel pump relay comes on and goes off, fan starts up, and the boost solenoid turns on.

Using the same pigtail and same wiring for both sensors. I'm gonna have to pull the sensor and have AEM check it out. But since I am running a JMFab Drag Manifold I have to pull that to get it out first.

Can't start the car right now cause the car is scaled for a 4 bar sensor