AEM A/F not reading properly on data log

[cbehr]

My x-series AEM A/F seems to be correct at the gauge but is not correct on my SCT and laptop, bouncing around 19.7 at idle vs gauge high 14’s.

I am using an SCT brand firewire with orange going to AEM white and blue going to ground. I have the AEM formula set on SCT device and double checked it is (v*2)+10 on livelink. Any idea why it’s not reflecting what’s on the gauge?

 

[gmtech]

Double check your ground for the fire wire. When I had trouble with AEM and data logging it was almost always the ground was poor causing voltages to read inaccurately. Move the ground to another location and recheck the log.

 

[cbehr]

Double check your ground for the fire wire. When I had trouble with AEM and data logging it was almost always the ground was poor causing voltages to read inaccurately. Move the ground to another location and recheck the log.

Thanks for the suggestion!

Where is the best place under the dash? I was using a screw on the metal surrounding the fuse block. I double checked all grounds were still connected, sanded the metal to remove any rust, reattached, and still 19.7 range. I'll try another grounding location, just curious where you guys use?

 

[cbehr]

So I ran a ground to the battery no difference, tried analog #2 on FireWire and no difference. Then I grabbed a multi meter and checked the wire from AEM gauge and it’s virtually steady at 5V which would make sense that the tuner is reading about 20. Any idea why the gauge is giving a 5V constant output? The ground on the gauge was run to the battery with the other grounds.