Calibrating AEM UEGO
02-18-2005, 10:31 PM
#1
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Thread Starter
Calibrating AEM UEGO
I'm attempting to calibrate my AEM UEGO (gaugeless) on my AEM EMS but not having much luck. I know it has been discussed here, but an extensive search was not fruitful. It is also discussed on the AEM Forum but once again it was hard to sort the wheat from the chaff.
My UEGO has only 3 wires connected. The orange wire (I believe the gauge type uses the white wire) goes to pin A16 on the AEM EMS extension harness. The red wire goes through a relay and a fuse to the battery. The black ground is grounded to the car body with a bolt where the old ECU lived.
I have screwed the wideband sensor into primary 02 port but not yet connected it to the lead to the controller box.
The relay has a ground attached to the same point as the controller ground and the 12V goes to one of the switched ACC lines to the ECU.
I can hear the relay close when I turn the key, and have registered 12V going to the controller.
When I monitor the O2 #1 Voltage on a laptop connected to the EMS I see less than 1V. I can adjust the gain and it moves the voltage a bit but nothing like the 4V we are expecting.
I have read that the best possible 12V and ground are preferred so tomorrow I willpull the lead back through the firewall and attach the red and black directly to the battery.
Also, I am not currently running the engine dring these tests the the voltage input is 12V not 14.4.
Can anyone who has been here give me some idea of what I am doing wrong and what I need to do to rectify it?
My UEGO has only 3 wires connected. The orange wire (I believe the gauge type uses the white wire) goes to pin A16 on the AEM EMS extension harness. The red wire goes through a relay and a fuse to the battery. The black ground is grounded to the car body with a bolt where the old ECU lived.
I have screwed the wideband sensor into primary 02 port but not yet connected it to the lead to the controller box.
The relay has a ground attached to the same point as the controller ground and the 12V goes to one of the switched ACC lines to the ECU.
I can hear the relay close when I turn the key, and have registered 12V going to the controller.
When I monitor the O2 #1 Voltage on a laptop connected to the EMS I see less than 1V. I can adjust the gain and it moves the voltage a bit but nothing like the 4V we are expecting.
I have read that the best possible 12V and ground are preferred so tomorrow I willpull the lead back through the firewall and attach the red and black directly to the battery.
Also, I am not currently running the engine dring these tests the the voltage input is 12V not 14.4.
Can anyone who has been here give me some idea of what I am doing wrong and what I need to do to rectify it?
02-19-2005, 09:57 AM
#2
Hmm... The instructions say 2 things of interest- the orange wire goes to pin C16 and "do not use the chassis as the power ground".
I did mine with the engine off and the sensor unplugged, The stock AEM calibration was very close to 4 volts, I barely had to change it. If the max voltage it is reading is 1 volt, I would look at Setup>Sensors>O2 Sensor #1. I can see the computer only reading 1 volt if the sensor is still setup as a narrowband in the workmap that is loaded in the AEM. I believe that I actually connected my ground and power directly to the AEM wiring harness.
Good luck!
Tim
I did mine with the engine off and the sensor unplugged, The stock AEM calibration was very close to 4 volts, I barely had to change it. If the max voltage it is reading is 1 volt, I would look at Setup>Sensors>O2 Sensor #1. I can see the computer only reading 1 volt if the sensor is still setup as a narrowband in the workmap that is loaded in the AEM. I believe that I actually connected my ground and power directly to the AEM wiring harness.
Good luck!
Tim
02-19-2005, 01:20 PM
#4
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Thread Starter
Originally Posted by timg' date='Feb 20 2005, 04:57 AM
the orange wire goes to pin C16 and "do not use the chassis as the power ground".
I'll run the ground to a ground on the AEM and see if it makes a difference.
02-19-2005, 06:29 PM
#5
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Thread Starter
Problem solved!
But you're not getting away with it that easy. I had to jump through hoops to solve it so I don't see why you should jump straight to the last page.
I rewired with the ground going to the ECU ground. No difference.
I disconnected it from ground, relay and C16 and connected the ground and 12V directly to a battery (a jumper pack fully charged). Still bugger all signal on the orange wire.
I then tested other wires thinking that it might be a slightly older or newer model to what I've been reading about. No go! Nothing! Zip!
At this point I resolve to pull the unit out, test it, perhaps disassemble it, and possibly send it back hoping like hell it is under warranty. It was then I realised/remembered that the signal and power leads were not hardwired to the unit but has a connector. I checked the connector and sure enough, the red wires socket/pin had receded into the plug. I pulled the cap out of the front, repositioned the socket/pin and put the plug back in.
Works like a dream. Got 3.6V straight up (as the gain was set very low from my experiments). 0.967 got me 4V exactly. Got under the car and connected up the sensor and covered the OEM socket.
Of course it didn't end there. When I went to start the car it turned over but wouldn't fire. A quick check of the fuses (I remembered this from someones write up) and the ignition fuse was blown. Replaced it, started the car and hey presto. What should have been a simple job became, due to a bad connector and some mild flu type symptoms, a three night job.
But you're not getting away with it that easy. I had to jump through hoops to solve it so I don't see why you should jump straight to the last page.
I rewired with the ground going to the ECU ground. No difference.
I disconnected it from ground, relay and C16 and connected the ground and 12V directly to a battery (a jumper pack fully charged). Still bugger all signal on the orange wire.
I then tested other wires thinking that it might be a slightly older or newer model to what I've been reading about. No go! Nothing! Zip!
At this point I resolve to pull the unit out, test it, perhaps disassemble it, and possibly send it back hoping like hell it is under warranty. It was then I realised/remembered that the signal and power leads were not hardwired to the unit but has a connector. I checked the connector and sure enough, the red wires socket/pin had receded into the plug. I pulled the cap out of the front, repositioned the socket/pin and put the plug back in.
Works like a dream. Got 3.6V straight up (as the gain was set very low from my experiments). 0.967 got me 4V exactly. Got under the car and connected up the sensor and covered the OEM socket.
Of course it didn't end there. When I went to start the car it turned over but wouldn't fire. A quick check of the fuses (I remembered this from someones write up) and the ignition fuse was blown. Replaced it, started the car and hey presto. What should have been a simple job became, due to a bad connector and some mild flu type symptoms, a three night job.
02-19-2005, 07:48 PM
#7
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Thread Starter
That I don't know. I noticed a strange burning type smell yesterday when I was working on the car but couldn't locate it. I better have some 15 amp fuses and handy and check all my insulations again.
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