e38 ecm - no ac press. signal voltage for wideband

2010 6.0-l96/6l90e swapped into 84 c20. im trying to log my aem wideband with hp tuners through the ac press. signal. i have the 5v wire from the wideband wired to the ac press. sig. pin 12 org/blk wire on the x1 connector. i have votlage there with the wideband powered up when backprobing with a voltmeter but in vcm scanner it always shows 0.00 volts. the truck had ac before the swap so im stumped as to why it wouldnt read the ac pressure signal. has anyone ever had this issue? im trying to tune the vve using afr error but without being able to log the wideband im hooped.

Check your wiring with a multimeter. Some vehicles don't use the black/red wire for 0-5v signal. On my truck, that wire was the reference and I had the same issue. I also had to ground the wide band through the AC sensor wiring, with it connected to frame ground it logged incorrectly.

IIRC, the E38 has a CAN interface. So, if you have the X-series version of the AEM wideband, you are WAY better off using the OBDII direct interface; than using the 0-5v signal.

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Originally Posted by destructiondylan

2010 6.0-l96/6l90e swapped into 84 c20. im trying to log my aem wideband with hp tuners through the ac press. signal. i have the 5v wire from the wideband wired to the ac press. sig. pin 12 org/blk wire on the x1 connector. i have votlage there with the wideband powered up when backprobing with a voltmeter but in vcm scanner it always shows 0.00 volts. the truck had ac before the swap so im stumped as to why it wouldnt read the ac pressure signal. has anyone ever had this issue? im trying to tune the vve using afr error but without being able to log the wideband im hooped.

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hey man did you ever figure this out I'm having the same problem now