We went to the dealer to pick up our CMSA4 early this morning after getting the lumbar adjustment in the drivers seat fixed yesterday. The car had sat outside overnight, and the temperature here got down into the single digits. When they went to bring the car around to the front of the dealership for us, they said the check engine light came on, and that it was not unusual for that to happen when the air temperature was below 32°. They asked us to wait while they checked it out, and about 25 minutes later they came back and said that the problem had resolved itself. I asked them what exactly turned the light on, and they said they did not know, and that they could not find any problems.

How could this be? If the light was turned on due to some fault, would not the computer store the trouble code and tell them what caused the light to come on?

Obviously I am concerned that something is wrong. Single-digit temperatures should not be turning on the check engine light unless there is a problem. It felt like they were just giving us the brushoff to get rid of us. Of course I am wondering if they merely erased the code with their OBD reader, and when the light did not re-appear, they figured they could just send us on our way.

 

I've had my (yellow) check engine light come on a couple of times recently in the (very) cold temps we're experiencing here in S Ontario. I did have it into the dealer last week for a regular service & advised them of what occurred and they basically told me the same thing. They checked the memory & found no issues and told me that a number of owners report that same issue once the temps get down to 'freezin' your ***' range. Basically said dont worry about it unless you experience power loss or other drive-ability issues. They've been very good to me so far so i'll take them at their word.

 

Thanks for taking the time to respond. When the light comes on in your car, how long does it stay on?

I'm still curious exactly what triggered the light, so I know what to do the next time it happens. One of the problems with the dealers' response is that there are dozens and dozens of different faults that could turn the light on, and for many of them there is no other indication to the driver that there is a problem other than the light itself.

So what am I supposed to do the next time I see it, and it's below 32 degrees? Ignore it and assume there's not a problem? But what if the light has come on because there really is a problem?

I know the dealer told you to ignore the light unless you have other indications that there really is a problem, but that absolutely contradicts what the owners manual says.

The dealers telling us to just ignore the light in cold weather just feels like a shoddy response to me. If it were a 10 year old car that i was trying to avoid spending $ for repairs, I could see that strategy, but a new car that we spent $38k for should be operating correctly.

I've read that BMW tests it's cars in the harsh winters of northern Scandinavia to flush out issues like this. It was about 7 degrees above in my area last night. That's not extreme cold, that's a normal winter temperature for many of us. If it were 30 below or less, yeah, I could see unforeseen issues starting to pop up, but I'm in New Jersey, not the Yukon...

 

The light came on for maybe 10-20 secs at most then turned off. Ridiculously cold weather probably coupled with parts of the car/engine not warmed up yet was what my tech said. And as i haven't experienced any other problems then i'm going to take him at his word. Just as a further bit, a buddy of mine has an Audi 4 that has experienced a similar problem in the last couple of weeks and his dealer made the same comment to him.

As for what the manual states, i have to believe MINI's manual wouldn't possibly state "if the light only comes on for a short period of time and no drive-ability issues result, please ignore it". BMW/MINI and 'The Manual' wants you taking the car to the dealer for service as often as possible. I'm not gonna worry about this issue unless it continues when the warmer weather arrives or i find another issue that might be related to it.

 

Thanks again. I'm assuming you are talking about much colder temps than we have seen here recently. I was thinking that it was some sort of temperature sensor that was out of range, and therefore the computer was assuming the sensor had failed, but +7 fahrenheit should not cause that sort of issue.

Guess I will just see if it happens again, and go from there.

 

One more point, if the light turns off in 10 or 20 seconds, that's not at all typical of an indication of a real issue. Once the OBD system detects a real issue, typically it won't turn the light off until it does not detect the original issue over several engine cycles in a row(warm up, cool down). So if it were a "real" but intermittent or borderline issue, you might see the light stay on for several days before turning off.

 

The worst we saw here in southern Ontario where i am was -25c (-13f) and a wind chill of -42c (-43f) just this week but both times the light came on for me was with temps around -10c (14f) just before Christmas. But i suspect you are right about the length of time the light stays on.

 

Thanks again, Mikey, really appreciate the input. If it happens again I'll make sure I post again.