CEL/12AD01

[FrankMstein]

Got check engine light and no other announcements in the display.
Bootmod3 says "12AD01 Lambda probe after cat: Signal firmly lying on skimmed." Cleared it and it came back again in 10 miles.
Programmed with OTS stage 1 93, wet aFe drop in filters, nothing else, all for 6mo. No noticeable loss in start, power, or drivability.

https://bmwfault.codes/XMLDiagView?d...YANAA0ADAANAA=

Fault Code Description
The diagnosis system monitors the voltage signal of the oxygen sensor after catalytic converter in case of change of the mixture.
Fault monitoring conditions:
The fault is detected when the signal voltage of the oxygen sensor is permanently less than 0.8 V.

Fault Code Conditions
Temperature precondition:
- Catalytic converter temperature greater than 500°C.
Time precondition:
- Constant exhaust mass flow greater than 50 kg/h.
Other preconditions:
- Engine running.
- Constant-speed driving between 50 km/h and 80 km/h during medium engine speed (1400 rpm to 3240 rpm).
- Duration of the constant-speed driving at least 10 min
- No fault memory entries that indicate a fault in the fuel-air mixture.
Control unit voltage: 11 V to 16 V.

Fault Time Condition
The fault is entered immediately.

Service Plan
Check if faults are entered to the following components/functions, then rectify these first:
- Fuel system
- Variable camshaft timing control
- Tank ventilation
- Ignition
- Injection system
- Crankshaft sensor
- Camshaft sensor
- Electromotive throttle actuator
- Hot-film air mass meter
Check exhaust system for leak tightness.
Check wiring harness between DME and oxygen sensor after catalytic converter.
Check crankcase ventilation.
Renew oxygen sensor after catalytic converter.


Thinking post cat O2...

[TopJimmy]

Probably

[FrankMstein]

It is, just waiting on the local shop to tell me which one it is. Is there a scan tool (from the app store) that will tell me? I got Bimmerliink and it doesn't.

[Abanoblabib15]

Originally Posted by FrankMstein

Got check engine light and no other announcements in the display.
Bootmod3 says "12AD01 Lambda probe after cat: Signal firmly lying on skimmed." Cleared it and it came back again in 10 miles.
Programmed with OTS stage 1 93, wet aFe drop in filters, nothing else, all for 6mo. No noticeable loss in start, power, or drivability.

https://bmwfault.codes/XMLDiagView?d...YANAA0ADAANAA=

Fault Code Description
The diagnosis system monitors the voltage signal of the oxygen sensor after catalytic converter in case of change of the mixture.
Fault monitoring conditions:
The fault is detected when the signal voltage of the oxygen sensor is permanently less than 0.8 V.

Fault Code Conditions
Temperature precondition:
- Catalytic converter temperature greater than 500°C.
Time precondition:
- Constant exhaust mass flow greater than 50 kg/h.
Other preconditions:
- Engine running.
- Constant-speed driving between 50 km/h and 80 km/h during medium engine speed (1400 rpm to 3240 rpm).
- Duration of the constant-speed driving at least 10 min
- No fault memory entries that indicate a fault in the fuel-air mixture.
Control unit voltage: 11 V to 16 V.

Fault Time Condition
The fault is entered immediately.

Service Plan
Check if faults are entered to the following components/functions, then rectify these first:
- Fuel system
- Variable camshaft timing control
- Tank ventilation
- Ignition
- Injection system
- Crankshaft sensor
- Camshaft sensor
- Electromotive throttle actuator
- Hot-film air mass meter
Check exhaust system for leak tightness.
Check wiring harness between DME and oxygen sensor after catalytic converter.
Check crankcase ventilation.
Renew oxygen sensor after catalytic converter.


Thinking post cat O2...

Hello, I’m running intro the same exact issue right now, I got a catted downpipe and a awe exhaust, and I got the same code you got, I was told to get a tune to remove it, but after getting the tune I got the code again, I was wondering what did you do about it, hoping you found a solution to it since it’s been 2 years, thankyou

[FrankMstein]

Well, I got another O2 sensor and it fixed the code. I believe it was the post cat.

[Abanoblabib15]

Originally Posted by FrankMstein

Well, I got another O2 sensor and it fixed the code. I believe it was the post cat.

I replaced my downstream o2 sensor yesterday and it came back on, do you know anything else I could fix

[FrankMstein]

Well, there is a YT on how to test them. If you're going to poke around, check out the connector. Or take it to someone with a real scanner.

[Abanoblabib15]

Which sensor did you end up changing

[FrankMstein]

Downstream