Increased Emissions and Ambient Temp Sensor

[Lorde]

I was driving the M this afternoon and on parking the car, all of a sudden I get the Increased emissions code and my ambient temperature gauges is reading 122 degrees Fahrenheit.

Reading the other threads I have seen replacement of O2 sensors and intake temp sensors. Any correlation between the Increased emissions and the ambient temp sensor?

When I start up the car after letting it cool off, it reads ambient temperature fine and after I start driving it, it all of a sudden reads 122 degrees.

Also, does anyone know where the ambient temperature sensor is located??

Thanks!

[Lorde]

UPDATE: They're going to replace the ambient temp sensor. So if you get an increased emissions light and your external temp is 90 degrees higher than it should be, this is what you should point out to your SA first. $45 temp sensor is going to be a cheaper replacement than an O2 sensor, especially if you're out of Warranty.

Found the following on M5board:

"I had it happen on my '07 M5 recently, but it started right about the time I noticed that my outside temperature sensor was acting strangely (it was telling me it was 122 deg. F. in Salt Lake City during a vacation...I'm pretty sure it wasn't). Anyway, it turns out the ECU relies on the ambient temperature sensor for certain adjustments to the engine. Apparently, not only was it telling me it was hotter than it really was outside, but it was messing with the engine as well. Don't know if you've noticed anything like that with yours, but it's a thought."

[THE TECH]

Interesting.

[Lorde]

They replaced the temp sensor, with no luck, still reading 122 degrees. They cleared the code and it came back on again. I am thinking that there is a short in the wiring from when they replaced the front bumper. Something is causing the circuit to stay closed. I read that an open circuit reads -40 degrees.

They said that the temp sensor needed to recalibrate but I think it's BS, have read that simple replacement of the sensor has solved the problem immediately. I'll five it a shot but will take it back on Monday if it doesn't work.

[THE TECH]

Originally Posted by Snig

They replaced the temp sensor, with no luck, still reading 122 degrees. They cleared the code and it came back on again. I am thinking that there is a short in the wiring from when they replaced the front bumper. Something is causing the circuit to stay closed. I read that an open circuit reads -40 degrees.

They said that the temp sensor needed to recalibrate but I think it's BS, have read that simple replacement of the sensor has solved the problem immediately. I'll five it a shot but will take it back on Monday if it doesn't work.

Hope it's just a minor problem.

[Lorde]

Originally Posted by THE TECH

Hope it's just a minor problem.

Ha, same here! Car isn't in limp mode, which is always a good sign. Just annoying.

[mocsman]

Brought in my car today after getting the increased emissions error. Was told by my SA that the thermostat regulator (is this the same temp sensor people are talking about?) had to be replaced and would cost me $1k to replace including parts and labor. They cleared the code and will check if it comes back up again. Don't want to commit to the the dealer to do the work especially if the sensor is just $45... I can have that replaced by a local shop. Thoughts?

Btw, i also got the engine malfunction, reduced power error last night but after idling it for 5-10 mins that went away. SA said the misfire was recorded but they won't be able to know what caused it until they have more time with the car. Was scary seeing that error... Hope it does not come back. Was hanging out at the pre-owned lot and saw a used 06' M5 for $34K... Got me thinking...

[Ezio]

Originally Posted by mocsman

Brought in my car today after getting the increased emissions error. Was told by my SA that the thermostat regulator (is this the same temp sensor people are talking about?) had to be replaced and would cost me $1k to replace including parts and labor. They cleared the code and will check if it comes back up again. Don't want to commit to the the dealer to do the work especially if the sensor is just $45... I can have that replaced by a local shop. Thoughts?

Btw, i also got the engine malfunction, reduced power error last night but after idling it for 5-10 mins that went away. SA said the misfire was recorded but they won't be able to know what caused it until they have more time with the car. Was scary seeing that error... Hope it does not come back. Was hanging out at the pre-owned lot and saw a used 06' M5 for $34K... Got me thinking...

idk my car is in the shop for the second time with increased error. but not having anything like what the OP said. it could be other reasons for you and me.

[Lorde]

Originally Posted by mocsman

Brought in my car today after getting the increased emissions error. Was told by my SA that the thermostat regulator (is this the same temp sensor people are talking about?) had to be replaced and would cost me $1k to replace including parts and labor. They cleared the code and will check if it comes back up again. Don't want to commit to the the dealer to do the work especially if the sensor is just $45... I can have that replaced by a local shop. Thoughts?

Btw, i also got the engine malfunction, reduced power error last night but after idling it for 5-10 mins that went away. SA said the misfire was recorded but they won't be able to know what caused it until they have more time with the car. Was scary seeing that error... Hope it does not come back. Was hanging out at the pre-owned lot and saw a used 06' M5 for $34K... Got me thinking...

My issue was ambient air temp sensor (outside air temp) being faulty. It sits on the driver side grille inlet that leads to the airbox.

[mocsman]

Just read the bill again from the diagnostic visit - it's the engine coolant thermostat. Where is the best place to buy this? Anyone who knows how to remove the code once replaced? I am in Delaware. Will check the regional section but hit me up if you can recommend a shop. Thanks.