E90 M3 P1209 ($07e8, $07e8pd) help needed

[extra_slick]

Hello -

My car went into limp mode the other night, got a reduced engine power idrive message, but no cel. Turned off and started again, no issue. Next day, went into limp mode 5 times over the course of 12 miles on the tail of the dragon, man was that a pain (good thing nobody else was following me). I read somewhere that it could be the brake vacuum sensor, but also saw one post saying it could be bad gas. I ran the tank dry, added a few gallons then ran dry again. Filled all the way and drove 250 miles with no issues. Figured it was the gas. Sure enough, tank is low again and I could barely drive 3 miles to work in limp mode and eventually got an SES light and an additional increased emissions idrive indication. I've ordered the brake vacuum sensor as that seems to be the solution, but my code reader shows two secondary messages as P1209 $07e8 and P1209 $07e8pd. What I'm wondering is what the $07e8 things refer to. However, I've also seen it tied to an injector control system pressure fault issue. What are my next steps to figuring out what the issue is? Could it be a fuel pump issue or clogged filter since it could be a fuel pressure issue? Car has 108k miles. Thanks.

[SUBFRAMERIPPER]

http://www.m3post.com/forums/showthread.php?t=928325

[extra_slick]

Originally Posted by SUBFRAMERIPPER

http://www.m3post.com/forums/showthread.php?t=928325

This doesn't help. I've already seen that link and searched everywhere. I'm trying to determine what the 07e8 thing means and can't find info on it anywhere. I'm trying to figure out whether this is the vacuum sensor or a fueling issue.

[msan]

Have you recently change your brake fluid?

[extra_slick]

Originally Posted by msan

Have you recently change your brake fluid?

I did, yes. I figured that's what the culprit was however I don't remember spilling fluid. Last night, I took off the reservoir and pulled out the sensor and the seal was a little beaten up and shredded. I put on some black rtv just as a band aid fix until my new sensor with vacuum piping comes in on Monday. After the rtv, only went into limp mode once in the same distance where it would do it five times.

[thasuperdude]

FWIW, I had a low fuel-pressure sensor that was going bad and it threw all kinds of codes, including engine mis-firing which scared the crap out of me. I changed the plugs and did a few other things, come to find out it was just the low fuel-pressure sensor on the fuel rail that runs behind the air box on the fire wall. $97 shipped and 20min to fix. ATL Dealer wanted $1500 to replace it. It resolved the 4 or 5 different codes I got.

[msan]

check back after replacing the brake vacuum sensor. May solve your issues.

[extra_slick]

Originally Posted by thasuperdude

FWIW, I had a low fuel-pressure sensor that was going bad and it threw all kinds of codes, including engine mis-firing which scared the crap out of me. I changed the plugs and did a few other things, come to find out it was just the low fuel-pressure sensor on the fuel rail that runs behind the air box on the fire wall. $97 shipped and 20min to fix. ATL Dealer wanted $1500 to replace it. It resolved the 4 or 5 different codes I got.

Part number?

[thasuperdude]

https://www.turnermotorsport.com/p-2...0-f01-f10-f12/

Looking for the DYI and can't seem to dig it up. There's a good youtube walk-thru.

[BayE30]

Originally Posted by msan

Have you recently change your brake fluid?

is there a special procedure to change brake fluid on these cars? spilled fluid from reservoir known to cause these issues?

[msan]

Originally Posted by SFCM3

is there a special procedure to change brake fluid on these cars? spilled fluid from reservoir known to cause these issues?

No special procedure. Just don't spill any . Also be careful when spreading the calipers (when changing pads or rotors) as this can push fluid out of the brake fluid reservoir and make it drip down which will also kill the sensor.

[BayE30]

Originally Posted by msan

No special procedure. Just don't spill any . Also be careful when spreading the calipers (when changing pads or rotors) as this can push fluid out of the brake fluid reservoir and make it drip down which will also kill the sensor.

Got it. usually the only time fluid spills out after spreading calipers is when people "top off" brake fluid...i keep trying to explain to people that if its low, your pads are probably worn out, but they continue to fill brake resv.

[extra_slick]

Originally Posted by thasuperdude

https://www.turnermotorsport.com/p-2...0-f01-f10-f12/

Looking for the DYI and can't seem to dig it up. There's a good youtube walk-thru.

Ordered it to have in case the sensor doesn't fix it. Both parts will be here Monday

[extra_slick]

Vacuum sensor was the cause. Now fixed.