[sayfn52]

my e90 doesn't have a check engine light i don't think i completed the 10-15 drive cycles needed but when i got my car smogged both times it failed and code p1727 came up along with obd2 failed. anyone know why ? [IMG][/IMG]

[sayfn52]

Originally Posted by sayfn52

my e90 doesn't have a check engine light i don't think i completed the 10-15 drive cycles needed but when i got my car smogged both times it failed and code p1727 came up along with obd2 failed. anyone know why ? [IMG][/IMG]

i've also driven over 400miles since i got all the codes fixed not sure why that code keeps coming up

[lookalikehuuh]

Its likely better to use a BMW centric scanner to pull the code because BMW doesn't do great with Generic OBDII.

P1727 I believe is a crank position sensor issue. While replacing the crank position sensor is really straightforward, getting to the sensor is kind of a pain since it lives under the starter.

[RayLivingston]

Can you communicate with the transmission controller?

Looks to me like that could be a failed/flaky crank position sensor. That is an inexpensive part, and should not be too difficult to replace. That's where I'd start. Bur you should have some kind of scan tool that can check for transmission faults. INPA will do it, as will the Foxwell NT510/520, with the BMW software module.

[dpaul]

Originally Posted by RayLivingston

Can you communicate with the transmission controller?

Looks to me like that could be a failed/flaky crank position sensor. That is an inexpensive part, and should not be too difficult to replace. That's where I'd start. Bur you should have some kind of scan tool that can check for transmission faults. INPA will do it, as will the Foxwell NT510/520, with the BMW software module.

RayLivingston has a good point - can you communicate with the transmission?

P1727, which is in fact a manufacture-specific trouble code, does not necessarily mean a problem with the crank position sensor, it means there is a problem with communication between the DME and the transmission control module. A problem with the signal from the crank sensor is one of a number of possible reason for that.

If you really had a crankshaft position sensor failure, you should get additional error codes, perhaps P0335.

If you do not have a decent scanner of your own, the best advice anyone can give you right now is to buy one so you can read and clear errors on your own. Even better, install BMW Standard Tools on your laptop, buy a KDCAN cable and learn a lot about what is really happening in your vehicle using full-functioned factory software.

[sayfn52]

Originally Posted by dpaul

RayLivingston has a good point - can you communicate with the transmission?

P1727, which is in fact a manufacture-specific trouble code, does not necessarily mean a problem with the crank position sensor, it means there is a problem with communication between the DME and the transmission control module. A problem with the signal from the crank sensor is one of a number of possible reason for that.

If you really had a crankshaft position sensor failure, you should get additional error codes, perhaps P0335.

If you do not have a decent scanner of your own, the best advice anyone can give you right now is to buy one so you can read and clear errors on your own. Even better, install BMW Standard Tools on your laptop, buy a KDCAN cable and learn a lot about what is really happening in your vehicle using full-functioned factory software.

the thing is my car doesn't have a check engine light on just got it fixed up. could it be that i haven't finished the 10-15 drive cycles ?

[RayLivingston]

Originally Posted by sayfn52

could it be that i haven't finished the 10-15 drive cycles ?

No. You will never see that code unless something is actually wrong. It has NOTHING to do with drive cycles, emissions monitors, or anything else.

Do you even have a scanner?

[sayfn52]

Originally Posted by RayLivingston

No. You will never see that code unless something is actually wrong. It has NOTHING to do with drive cycles, emissions monitors, or anything else.

Do you even have a scanner?

the smog place is giving me these codes that's why i ask and i doubt they have a bmw centric scanner i don't have a check engine light either so i doubt there will be any codes

[lowrydr310]

You need to read the details of the stored code. Buy a scanner that can read the BMW-specific codes and see what's there. Or take your car to a shop that specializes in BMWs and they will certainly have the scanner and can make a proper diagnosis. To reiterate what everyone else said here, NO that code has nothing to do with completing the drive cycles and it isn't going to just go away on its own.

Without having any more detail, nobody here can help.

It is strange that you don't have a SES (Service Engine Soon a.k.a "check engine") light and failed the OBDII portion of the test. I thought any codes that would result in an emissions test failure would most definitely trigger the SES light. Is your SES light burned out or was it removed? When you first put the key in the ignition and press the start button without holding the brake (or clutch if you have a manual) and the gauges do their self test, can you confirm that the SES light is illuminated?

Have you owned this car for a while or did you just recently purchase it?

Originally Posted by sayfn52

the smog place is giving me these codes that's why i ask and i doubt they have a bmw centric scanner i don't have a check engine light either so i doubt there will be any codes

There is a code in your smog test report, so I don't see why you're saying there won't be any codes. You already have a code. With the BMW-specific scanner you'll get a lot more detail about the specific fault that's triggering that generic P-code on the OBDII test.

[sayfn52]

Originally Posted by lowrydr310

You need to read the details of the stored code. Buy a scanner that can read the BMW-specific codes and see what's there. Or take your car to a shop that specializes in BMWs and they will certainly have the scanner and can make a proper diagnosis. To reiterate what everyone else said here, NO that code has nothing to do with completing the drive cycles and it isn't going to just go away on its own.

Without having any more detail, nobody here can help.

It is strange that you don't have a SES (Service Engine Soon a.k.a "check engine") light and failed the OBDII portion of the test. I thought any codes that would result in an emissions test failure would most definitely trigger the SES light. Is your SES light burned out or was it removed? When you first put the key in the ignition and press the start button without holding the brake (or clutch if you have a manual) and the gauges do their self test, can you confirm that the SES light is illuminated?

Have you owned this car for a while or did you just recently purchase it?

There is a code in your smog test report, so I don't see why you're saying there won't be any codes. You already have a code. With the BMW-specific scanner you'll get a lot more detail about the specific fault that's triggering that generic P-code on the OBDII test.

i've had it for a while. and yes before i turn it on the service engine light is on but goes away when i turn the car fully on. my uncle just recently did a lot of work on it and told me he fixed all the codes. i've driven it over 200 miles with no check engine light. so yeah it's weird and got me confused