MS3PNP to AEM X-Series Wideband Connections
 

Just thought I would post this up in case anyone ever looks it up. I am connecting this as follows:

MS3PNP Harness PIN G (CANL) to the AEM CANL (Green/Black wire) - PIN 3
MS3PNP Harness PIN I (CANH) to the AEM CANH (White/Black wire) - PIN 4
MS3PNP Harness PIN A (Sensor Ground) to the AEM 0-5V Analog output Negative (Brown wire) - PIN 10
MS3PNP Harness PIN C (Analog Input) to the AEM 0-5V Analog output Positive (White wire) - PIN 9

AEM Switched 12V Power (5a Fuse) (Red Wire) - PIN 1: Will be tapped into an existing fuse in the engine's fuse box.
AEM PowerGround (Black Wire) - PIN 2: Will be grounded somewhere in the engine bay

AEM PIN 5 (Blue wire is for a serial output)
AEM PINS 6-8 are not used

Any reason you are connecting both the analog and the CAN wires? You should only need one or the other.

It was recommended by the makers of the Megasquirt. Any reasons why you think otherwise, could signals cross? I get that analog could be one method and CAN a second method, but I have to go by what the manufacturer says to do. I sent a follow-up to them asking what the reasons were that both should be wired up.

You can only use one. I would recommend CAN since it'll always be the same as the gauge. If you use the analog it might have a small difference that some people find concerning. If you use CAN, you can set the analog to a generic 0-5v input, however the MS won't be able to use it as anything but a monitor.

I originally wired for CAN, agree with you there, but then I had a power question that I sent to MS and I was told to wire the analog as well. I didn't reply back well enough, and should have asked why to wire both CAN and analog, but I sent that question earlier today so I should hear back on Monday.

Do you see any issues with both CAN and analog wires? My assumption is we direct the Megasquirt to look for CAN, not analog, so it should not be an issue to have both wired up, but do you know anything about that?

Yes I do. It’s fine. But you can only assign one as the official EGO sensor. So I’d suggest CAN. They might have suggested analog so the grounds hooked up?

You might be on to something there. This is from MS about wiring the analog, which jives to what you are saying.

"This is the reason that extra ground wire is provided, rather than just tying it to the power ground, in order to isolate it from the current-carrying grounds in order to give you an accurate, stable reading. "

This was a great tip provided by them, just getting it out there in case anyone reads this thread.

"One final recommendation I forgot, it's often good practice to pull the power from the fuel pump relay so that you don't run the risk of having the sensor powered for an extended period of time while the engine is NOT running, as this poses a risk of water condensate (e.g. from a cold start) hitting the heated sensor and shock-cooling it."

When using CAN, both CAN and analog should be hooked up for grounding purposes, but if you use analog then there is no need to wire the CAN.