AEM UEGO + HPTuners EIO

[white.lightning]

Hey everyone. I've searched for my answer and could not find it. I have a specific question about the wiring of my AEM UEGO wideband gauge.

Currently, I have the following hooked up:
-Red wire to a switched 12v source- taken from a wire going to the fuse block in the cabin w/ a 10a fuse....wired down stream of the fuse.
-Black wire to a ground wire found near the stereo- appears to be linked to the power source plug in front of the emergency brake
-White wire to HPTuners EIO pin #1
-HPTuners EIO pin #5 to a ground wire under the center console

My questions are:
-Does the gauge black wire and EIO pin #5 wire need to be grounded to the same source?
-Should I sand paint away off the chassis underneath the center console and put both wires under a self tapping sheet metal screw to ensure a good ground?

Reason I am asking is I feel as though I have some discrepancies between the AFR gauge read out and the AFR being logged. I searched the AEM forums and will confirm the following:
-Sensor unplugged- gauge reads 14.7 AFR
-Sensor unplugged- white wire voltage between 2.35-2.40vdc
-Remove sensor from exhaust pipe- confirm sensor is working by doing the rag/brake cleaner test

Comments/concerns?

Thanks,
Andrew

[fasthotrod]

If you look in the manual for the AFR gauge, you'll see that 14.7 AFR is approximately 2.35 VDC.

11 AFR = 0.5 VDC output
15 AFR = 2.5 VDC output

Therefore, a change of 0.2 AFR is a change of 0.1 VDC, between the 0-5 VDC swing... so if that is what you have on your gauge, then it's right per the readout.

If you have issues with what HP Tuners is reading/logging vs. what the meter says, then you are on the right track with the ground point. I would ground the wideband and the EIO at the same point to try and eliminate any potential (voltage potential) difference between the two. While sanding the metal will help, it's best to just run a wire between the two for the best connection.

Mark

[white.lightning]

Thanks for the reply!

[5_Liter_Eater]

David, I'm not familiar with EIO. I pipe my AEM WB into HPT using the AC pressure signal (different subject). Anyway. When piping through the AC I am very famliiar with ground offset problems. I like the idea about grounding the EIO and AEM to the same place. If HPT is still not matching the AEM then you will need to create your own user defined PID for the WB AFR instead of using the built in one. Then edit the offset up or down until the match. Take camera phone pics of HPT next to the gauge and average 4-5 snaps. Keep asjusting the offset until they match. Leave the slope the same. Start out with V/.5+10 and move the +10.

HTH

[white.lightning]

I just went out and took the gauge ground and EIO pin #5 ground wire and grounded them together. I sanded the paint off the chassis in front of the airbag module. Then I used a self tapping hex head screw with a ring terminal and washer to hold everything in place. I will do the gauge/sensor test later this week when it warms up.

[AJII]

Related question..can you just simply run the black ground wire to the MPVI Pro pin #5?

This is how I have mine, and just want to make sure I am not doing it incorrectly.

[white.lightning]

If you do that, it isn't being grounded. The EIO plugs into the HPTuners Pro MPVI box, which plugs into your laptop which is not grounded.

You need to get both to a good chassis ground

[AJII]

I hooked it up according to this link, which doesn't show a separate ground, only the ground from the WB to the MPVI.
http://www.hptuners.com/help/index.h...connecting.htm

How would I know if it's not being grounded properly?

[white.lightning]

The only thing I can think is that the MPVI Pro is using the OBD2 port as a ground. Basically I did the same thing you did, except I have a self tapping screw and a ring terminal coupling the wire to the chassis as an added effort.

I think the way you have it hooked up is fine