AEM UEGO sensor get hot w/o engine running

EVIL-EVO-8 · Oct 21, 2009, 05:41 PM

Just got my car all put together and was under it with the aem program running connected to the EMS getting ready to start it for the first time w/ new motor. I touched my arm on the sensor and its hot as hell. Is this normal?

Juan MR · Oct 21, 2009, 05:43 PM

Quote:

Originally Posted by EVIL-EVO-8

Just got my car all put together and was under it with the aem program running connected to the EMS getting ready to start it for the first time w/ new motor. I touched my arm on the sensor and its hot as hell. Is this normal?

nope not normal at all , make sure u have it wired in correctly

EVIL-EVO-8 · Oct 21, 2009, 06:02 PM

it plugs into the aem so not sure where the problem could be

EVIL-EVO-8 · Oct 21, 2009, 06:07 PM

its going to 4.75 volts when i plug it in. the gain isnt changing it at all

awdboosted · Oct 21, 2009, 07:25 PM

If the key is on it should be hot. The sensor has a heater element on it.

EVIL-EVO-8 · Oct 21, 2009, 09:40 PM

ok cool. but why are the volts not changing?

MasterNater · Oct 21, 2009, 11:44 PM

Yes, the sensor should get hot when you turn the ignition on and the engine is not running. It's simply the preheat. It's to help protect the cold sensor from suddenly getting "shocked" by the hot exhaust gases.

You said the sensor plugs into the EMS, so I'm guessing you are using the 1313U with built in wideband controller. You are supposed to calibrate the lambda sensor channel with the sensor unplugged. Then you can adjust the O2 Sensor Gain up and down until the "O2 Sensor #1 Volts" parameter reads the correct voltage of 3.94 (+/- .02 volts). I believe my gain is set at 1.26.

EVIL-EVO-8 · Oct 22, 2009, 12:13 PM

Ok ya I wasnt sure if it was getting hot due to the volts shooting up. I tried to set it up like the manual says with no luck. Do you control the volts with the gain? whats happening Is I changed it with the sensor unpluged then when i plug it in the volts start going up and then shoot to 5.75ish and stay there. Im not sure how to get it to stop this? Thanks, MIke

awdboosted · Oct 22, 2009, 12:13 PM

Quote:

Originally Posted by EVIL-EVO-8

ok cool. but why are the volts not changing?

Because the car isn't running. Nothing to sample but just air.

MasterNater · Oct 22, 2009, 01:13 PM

Quote:

Originally Posted by awdboosted

Because the car isn't running. Nothing to sample but just air.

Correct. When you plug the o2 sensor in and the engine is not running, it's reading 100% oxygen, causing the voltage to max out. That's completely normal. Once you start the car, and the AFR's change, the voltage will change as well.

awdboosted · Oct 22, 2009, 04:41 PM

This is used to calibrate the Wideband to the EMS..

-Make sure the wizard is set up right for the 02 wizard
-Unplug the wideband from the connector next to the sensor.
-adjust gain until the AFR reads 14.7 or what MasterNater said 3.94 (+/- .02) volts in the EMS.
-Plug it in and you’re done.

Sorry to repeat, I'm just trying to give step by step instructions.

EVIL-EVO-8 · Oct 26, 2009, 12:55 PM

ok thanks to you all! Got it figured out. Delayed another week til ignition though, Filled up the radiator and was going to start the car and now I have a coolant leak from who knows where. AARRRRGGGG complete builds suck!! issue, issue, problem, delay, delay!!! Hate this crap.