I didn't know AEM even fixed that trim. Isn't that part of the diode fix I keep hearing the guys at AEM forum talking about? My serial number is one that already has the "fix" but my voltage reading is all over the place. I zero'd out the voltage compensation map. It reads >16v except at idle then it jumps all over. Voltage at the AEM input is solid according to my DMM. Just one of many bugs I've found in the unit. I quit trying to keep track of them since AEM never answers me about it.

 

It's been a long time so I may be a little off here, but when I first received my unit (mid 30's SN, 2005 I think) the "battery voltage" was accurate at idle, but as soon as you touch the throttle (any variation of TPS) it would quickly ramp to zero. It would screw up a few trims. Sent it back and had the diode fix and it's been fine/accurate ever since.

You probably don't need the trim if your other idle parameters are perfect and your idle closed loop fuel control is set right. Mine are like 85% good and without the idle/voltage trim my car would most likely stall with the headlights and wipers on. Voltage goes down a lot on my car at idle.

 

Jeff, I've been trying to pm you about oil gears but your inbox is full. Please send me an email to: rfernandez@codetel.net.do.

Thanks,

Rafa

 

I have the idle feedback pretty close but because of the a/f drift it'll never be accurate. Some days it's -12 learned value. Other days it's +8. Sometimes it's right on about -1 or -2. I can't get it stable and figured that's just the way it is. What's interesting is the EMS can see the headlights turning on, the vent blower on #3 or higher, and load on the power steering. You can see the state of the inputs change in Setup>Parameters>Inputs yet you can't program idle compensation for any of those. The factory ECU did.