AEM can lambda signal drops in and out

[06 STI]

06 Subaru STI with a wrx104x, with an AEM X series can lambda. The can lambda signal comes and goes. I have attached a log for reference. I installed the sensor in the factory wideband sensor location.

ECU Log 2024-05-30 9;21;11 pm.llgx

[Vaughan]

Hard to tell from the ECU Log, could you get a PCLog of it happening? Would be looking for CAN errors to see if the CAN bus is going down. I assume the gauge always shows normally values?

Also I assume you have Analog Inputs -> Lambda 1 -> Lambda Sensor Control set to "Link CAN"

[06 STI]

Yes to the set up. Here is a pc log. If it doesn't show what you need let me know what that is and i will log it and share.

PC Datalog - 2024-05-30 7;24;51 pm.llgx

[Vaughan]

That PCLog barely has anything it and doesn't specifically have the CAN statuses for whichever CAN bus you are using. If possible go into the Logging Setup Window and hit the "Add All>>" in the PC Logging tab.

Does the Lambda Gauge always display real numbers? even when the ECU value is 0?

 

[06 STI]

No, the reading drops to 0 then returns at random intervals. Sometimes it will work for a while, then drop for a short tine before returning. other times it will not work for an extended period of time then blink in & out in short burst. I will log all the next time i drive the car. and post then. I do know that the tuning window shows no can or lambda faults when the signal drops out.

[Vaughan]

CAN errors won't show up in the "Fault Codes" or "Fault Code Count" runtimes. If the gauge display itself is dropping to zero then the issue is not in the ECU but rather in the wideband controller.

[06 STI]

https://drive.google.com/file/d/15mgjTfacLZ-FxE6GSlW1WkrbP5dqBJ9u/view?usp=drive_link

 

Here is a log i was able to take after work today.(I hope i did that right.) I could not find an error code from the CAN, but I am new to both efi and can networks. So any help in sorting this out is greatly appreciated.

[Vaughan]

There are no errors showing up in the CAN bus.

Just to clarify based on your answers above if the reading on the gauge itself is going to zero then the issue is with the gauge itself, if the gauge is showing a normal number and the ECU is showing zero then it is probably not an issue with the gauge/sensor.

Can you attach a copy of your tune please so I can confirm your configuration.

[06 STI]

https://drive.google.com/file/d/1u48jOwLTcadnkHm1pw_fGV0pLco5Km21/view?usp=drive_link

I do not have a physical gauge. Just the can lambda tapped to the ecu. The car had an Innovate wideband on it from a previous owner. The lack of reading is solely on the ecu tuning.

[Vaughan]

The ID Position should be set to None

[06 STI]

That fixed it. Thank you for your help. Now to fix the problem with the too high of an idle. Something changed after my drive home from work lat night. Now I can't get the car to idle under 1000 rpm.

[David Ferguson]

Look for a intake manifold leak.  You probably have a cracked / split hose, or a vacuum line or cap has become disconnected.

[06 STI]

Yes I did it was just under the manifold and hard to see/get to. But thank you both for the help.