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Old AEM wideband install into S300v3 P28

Posted: Sun Feb 04, 2018 10:30 am
by 2x0
So I have an older aem wideband (probably 7 years or so) installed by previous owner that was never wired to the ecu. Looking to hook this up finally.

It’s a P28 with S300v3, running a B18c1. Car was a ‘91 obd0 coverted to OBD1.

Now, I understand I should be running the white wire to D10. Is it okay to cut the existing D10 wire and hook up to this? Then just remove the resistors 136 and 138, set my voltage in Smanager and I am done?

Thanks

Re: Old AEM wideband install into S300v3 P28

Posted: Sun Feb 04, 2018 3:35 pm
by skaterguy1986
I used the O2 input and didn't alter anything on the board, much easier. I also cut nothing on the original harness, just cut the harness off a dead O2 sensor I had laying around and spliced the white wire to the O2 sensors signal wire then plugged it into the factory harness. The ground must be at the same spot at the ECU (thermostat) for the closest accuracy but you'll probably still have to set a small offset for the SManager to show the same AFR as the gauge. The settings in SManager can easily be found by a quick google search.

Re: Old AEM wideband install into S300v3 P28

Posted: Sun Feb 04, 2018 7:31 pm
by 2x0
OK that made me more confused about cutting the harness off a dead sensor. I have my stock narrowband still running for closed loop. I have my wideband running the gauge only and want to hook it up to ecu for datalogging the easiest way possible.

The white wire should run to the ecu, is there a simpler way than using D10?

Re: Old AEM wideband install into S300v3 P28

Posted: Mon Feb 05, 2018 10:27 am
by Spunkster
Connecting to D10 is the easiest method.

Re: Old AEM wideband install into S300v3 P28

Posted: Tue Feb 06, 2018 10:19 am
by 2x0
Thanks. Can I cut the wire currently going to D10, or do I need to splice into it?

Is removing the resistors 100% necessary, or should I see how it works first while leaving them in?

Re: Old AEM wideband install into S300v3 P28

Posted: Tue Feb 06, 2018 11:42 am
by Spunkster
It needs to be cut or de-pinned and a new wire run to it. You cannot just splice into it.

Re: Old AEM wideband install into S300v3 P28

Posted: Tue Feb 06, 2018 12:27 pm
by skaterguy1986
What's the point of using the factory narrowband if you're going to use a wideband that sends a signal to the ECU? You can control closed loop that way as long as you set the voltages up correctly.

Re: Old AEM wideband install into S300v3 P28

Posted: Sat Mar 10, 2018 8:49 am
by 2x0
Yes that is the plan once I get the wideband calibrated correctly in Smanager.

Thanks for the help gents

Re: Old AEM wideband install into S300v3 P28

Posted: Sun Mar 11, 2018 11:42 pm
by forevertrj
wide band sensors burn out faster, if you are in a pinch you could alter your program back onto the narrow band until you replace your wide band, also the reason for using d10 pin is for voltage clarity, the O2 narrowband only sees up to 3.83 volts or something where the D10 with the cut resistors has a 0-5v reading.

Re: Old AEM wideband install into S300v3 P28

Posted: Sat Mar 17, 2018 9:21 am
by 2x0
I have the resistors cut and wideband hooked up to D10. I haven't tried it out yet, just wondering do I need to check "disable ELD" in Smanager?

Re: Old AEM wideband install into S300v3 P28

Posted: Sat Mar 17, 2018 4:28 pm
by 2x0
Okay it seems to be working good with “disable ELD” checked. The readings in Smanager are about 0.1 to 0.2 AFR leaner than what my wideband gauge says. How do I adjust the voltage offset for that?

Re: Old AEM wideband install into S300v3 P28

Posted: Mon Mar 19, 2018 10:36 am
by Spunkster
You will just have to try changing the voltage offset a little at a time until you find the value that allows it to match.

Re: Old AEM wideband install into S300v3 P28

Posted: Mon Mar 19, 2018 3:03 pm
by Db7dud
I hate to bring this back up, sorry but I am having an issue with my aem x series wideband, I have power ran to switched 12v in driver side fuse panel, aem ground wire ran to thermostat housing, and white wire ran to d10, and my readings are so erratic and the wideband reading in s manager doesn't react until the car is given gas etc..any input?

Re: Old AEM wideband install into S300v3 P28

Posted: Mon Mar 19, 2018 3:06 pm
by Db7dud
Also 136 and 138 were removed from the board, sorry forgot to add that. I am assuming it is in my calibration

Re: Old AEM wideband install into S300v3 P28

Posted: Mon Mar 19, 2018 3:21 pm
by Spunkster
It sounds like a problem with the wideband controller not being able to give enough power to the analog signal at all times. You may want to contact AEM about this.