Interesting. The full description in the Workshop Manual is "Lambda regulation ... Additive value for self-adaptation" Google tells me this is short term fuel trim. http://wiki.bavariantechnic.com/index.php?title=Engine_Mixture_Adaptations We just need to find out whether yours is positive (lean) or negative (rich) There is also another code 1212 "Lambda regulation.... Multiplicative value for self-adaptation". Google tells me this is long term fuel trim. Did you see the recent post about how to interpret long/short term fuel trims (or rather the link to a YouTube video on how to do this)?
Can't find the post, but I bookmarked the YouTube video... I think Dave Rocks (StickyRX) provided the link?
Excellent video. Opens so many possibilities. I do get a high idle sometime when engine is run for awhile. Could be vacuum leak. .
1211 is not LT or ST fuel trim. They are both 1212. 1211 is a general lambda control code indicating problems with signal from the O2 sensor. Cause is varied, could just be the O2 sensor on the way out. Image Unavailable, Please Login
I replaced the temp sensor in the intake for the 5-8 bank. I cleared the code but when I started the car the CEL was still on. I drove it a few miles and the CEL light went off and stayed off. Before the change the light would not go off even after clearing the codes. Weather is not good here, going to storm so did not drivc more than a couple miles but light stayed off. Hopefully this solves the problem because car runs really great.
Odd. Temp sensor would throw a 1112 code. I'd check the codes again. Just because the CEL went off doesn't mean there isn't a code stored.
Could the bad temp sensor give the computer a false signal to add or subtract fuel causing the lambda regulation code?
Frankly I don't know. I had a bad coolant TS and never got the lambda code. If the TS is bad I think the car (or bank) stays in open look mode. In my case the TS was intermittent. I could put it in water an heat it up and it would work fine, then all of a sudden go to infinite impedance. When it cooled down it would work normally again for a while. The other thing I will state, now that I've put a 100 miles or so of CEL free driving on my car, is that I was getting an intermittent 1211 code. CEL would come on, then go off and stay off for a while. Then repeat. No apparent drivability issues but it smelled rich. Finally it threw a 1111 code (MAF). I replaced the MAF and all has been good since. No 1211 codes, no CELS. That's the problem with the 1211 code. It can be a lot of things, O2 sensor, MAF, fuel pressure, injector problem, wiring..... Without and SD1 read out it's kind of a guessing game. Basically 1211 is just saying the signal from the sensor isn't behaving the way it's expected to.
Well there's a trap for newbies... I saw the table like this... Image Unavailable, Please Login I didn't notice the same code 1212 below the highlighted box.
Well, we know one thing for sure, 1211 and/or 1212 means you have some type of lambda control problem. Either way, it's not clear as the 1212 code indicates two possible problems.
For me and the 348 Engine, it was Mass Air Flow sensor for both. This may not apply for the Tipo 129, but in my book the same code was also described as lambda control problem. I had them repaired by Fuel Injection corp, and no problems since (been a couple years). Btw, the car would run fine, but that check engine light would come on. I hope this helps you.
Good to know. Getting 7 inches of rain today so will test car tomorrow and see if light comes back on
Here is the thread with my specific issue and resolution https://www.ferrarichat.com/forum/threads/mass-air-flow-sensor-maf-available-anywhere-saab-version.495032/
Have driven car 200 miles and code has not returned. The temp sensor seems like it was the problem producing the code. Idle does not smell rich anymore either.
On my 348, I was getting a random intermittent 1211 and 1212 that I thought was my coolant sensors. The car ran perfectly fine so I wasn't too worried. But last week, I cut the battery for 24 hours to reset the ECU's. Then I unplugged the MAF kinda half ass brushed off the pins and blew out the plug like an old Nintendo game. The car was trouble free and code free for the near 800 miles on my Monterey trip this weekend. Maybe there was a bad connection, or maybe the I was due due for an ECU reset. I still plan on doing the sensors though. They are cheap and 28 years old. It will be good peace of mind.
