service engine light.

I'm sure there are tons of codes that set this light off, new to the e46 community and wondering what issues most commonly make it come on. i.e. plugs, air filter, etc? Or are we talking something a little more involved like an o2 sensor? Any feedback would be appreciated. Thanks.

The possibilities are endless. No use in guessing.

So my best bet is to take it in to a shop to be diagnosed? Any DIY ways of finding out which code it is?

Go to Autozone, they will give you a print out for free of the codes. Then take the codes and search for them on the forum.

Thanks, found the codes here on the site.

What was your code? Just curious

Sent from my PC36100 using Bimmer App

My engine light came on and was diagnosed as cyclone valve fault and thermostat fault.

Cyclone vale??? thermostate fault I can understand..a cyclone valve?..never heard of it..

If you're in the cold, and the SES pops up every month or so, usually it's the gas cap that throws this off. If it wasn't properly secured during a fill up, it'll put on the SES light. Unscrew the gas cap and screw it back in, then for the light to be reset, it usually takes 2 to 3 days of driving at various speeds. I've had this problem almost every winter.

Originally Posted by AlpinewhiteXi

I'm sure there are tons of codes that set this light off, new to the e46 community and wondering what issues most commonly make it come on. i.e. plugs, air filter, etc? Or are we talking something a little more involved like an o2 sensor? Any feedback would be appreciated. Thanks.

10 year-old BMW? Time to invest in a Peake tool . . .

Originally Posted by SILVRRONIN

Cyclone vale??? thermostate fault I can understand..a cyclone valve?..never heard of it..

I had to look it up too. It's the CCV.

Originally Posted by Kubica

10 year-old BMW? Time to invest in a Peake tool . . .

I think its the best to do it if you have intention to keep the car for more then one year, I just bought one yesterday when for the first time the SES turns on.

Originally Posted by anhtu402

What was your code? Just curious

Sent from my PC36100 using Bimmer App

I came up with p0128. I reset the code and will see if it comes back on. From my research sounds like it is most commonly the thermostat that throws this code due to the engine not heating up fast enough. Could be from some of the brutal cold days we have had in the past couple months here in Denver. If it is the thermostat at least it's easy to replace

Originally Posted by Kubica

10 year-old BMW? Time to invest in a Peake tool . . .

Actron scanner, Thanks.

Originally Posted by AlpinewhiteXi

I came up with p0128. I reset the code and will see if it comes back on. From my research sounds like it is most commonly the thermostat that throws this code due to the engine not heating up fast enough. Could be from some of the brutal cold days we have had in the past couple months here in Denver. If it is the thermostat at least it's easy to replace

That's thermostat stuck open code- replace thermostat soon.

Originally Posted by Kubica

That's thermostat stuck open code- replace thermostat soon.

Got it thanks!

Originally Posted by Kubica

10 year-old BMW? Time to invest in a Peake tool . . .

^+1

To help diagnosis codes in the future...

Can't go wrong with PEAKE!

Manufactured specifically for BMWs, Peake scan/reset tools make servicing your BMW cheaper and easier than ever.

The tool easily connects to your diagnostic port in the engine bay and allows you to read any codes for a check engine light as well reset your oil service and inspection light with the push of a button.

This tool is a must for the first time do-it-yourself mechanic and to complete any tool box.

Click HERE to order or for more information.


Please let us know if you have any questions! Feel free to shoot me a PM or email.

Best,
Joe

Originally Posted by ECSTuningJoe

^+1

To help diagnosis codes in the future...

Can't go wrong with PEAKE!

Manufactured specifically for BMWs, Peake scan/reset tools make servicing your BMW cheaper and easier than ever.

The tool easily connects to your diagnostic port in the engine bay and allows you to read any codes for a check engine light as well reset your oil service and inspection light with the push of a button.

This tool is a must for the first time do-it-yourself mechanic and to complete any tool box.

Click HERE to order or for more information.


Please let us know if you have any questions! Feel free to shoot me a PM or email.

Best,
Joe

Good to know. I will definitely be buying one shortly. Thanks for the heads up.

So, its been a couple of weeks weather has been warm with a couple cold days mixed in. I reset the code it came back. Did some research and discovered that the thermostat temp sensor is $15 vs. 50-60 for the thermostat and housing. While deciding too do both or just the sensor the SES light went off and has not come back on for the last couple of days and it has been cold outside. Im begining to think that just the sensor is faulty. Input? Thanks.