Start Off Assistance Inactive!

[mikep]

Hi All.

My 2008 M3 just recently started flashing up a yellow warning saying

"Start Off Assisance Inactive!"

I didnt notice any change in the car when driving around the city, and when I turn the car off, the warning always goes away. It will always come back though, sometimes when I first start the car, and other times after I've been driving for a while.

On the weekend I took my first road trip with the car, and the car would either suddenly accelerate or decelerate when driving with cruise control on, and then the "Start Off Assistance Inactive" light would come on. After the light came on the car drove normally.

Any ideas? Sensor?

BMW told me they had no ideas but would be happy to diagnose for $130/hr. They told me that nothing came up on my key when they put it into their computer.

[abehwang]

isnt that the mechanism where it holds your car for a second on a hill so it doesnt roll back?

[mikep]

Ya I think so.

I thought it might be caused by low brake fluid, but I checked it and it's full, and that wouldn't explain the weird way the cruise control was working I suppose.

[e1000]

Did you recently get new wheels or tires?

[mikep]

no i have 245/35R19 front and 265/35R19 rear that have been on the car for a year or more, with factory rims.

[apecush]

warranty still valid? Sounds like this should be covered....with no diagnostic fee.

[ec_E92]

I believe this is tied into the DSC system. Can you get a code reader to check for fault codes stored on the DSC control unit? That would help us to get a better picture of the issue (sensor, wire short, bad module, etc).

[sos]

Originally Posted by ec_E92

I believe this is tied into the DSC system. Can you get a code reader to check for fault codes stored on the DSC control unit? That would help us to get a better picture of the issue (sensor, wire short, bad module, etc).

Correct, part of the DSC+ system installed on all 6+ cylinder BMW cars after March 2007 IIRC.

Wonder if any of the other features aren't working either......

Maybe it's an angle sensor that's gone to detect car is on a hill?

Originally Posted by BMW_Info_Somewhere

Six-cylinder models are offered with DSC+, which adds five additional features:

Brake Standby primes the brakes when it detects the driver suddenly lifting off the throttle

Rain Brake Support gently applies the brakes in the wet - imperceptibly to the driver - to dry the discs

Hill Start Assist holds manual versions on a gradient allowing the driver to pull away without rolling backwards

Fading Compensation detects brake fade and applies increased braking pressure

Soft Stop releases a small proportion of braking pressure at the end of the braking cycle for gentler stopping, although it deactivates in emergency stops.

[ec_E92]

Originally Posted by sos

Correct, part of the DSC+ system installed on all 6+ cylinder BMW cars after March 2007 IIRC.

Wonder if any of the other features aren't working either......

Maybe it's an angle sensor that's gone to detect car is on a hill?

Correct, all NA M3's (2008+) should have the updated DSC system. I was looking around and can't tell if the module has built in yaw, G and angle sensors or if they are external.

Ref: http://wds.spaghetticoder.org

[mikep]

Originally Posted by ec_E92

I believe this is tied into the DSC system. Can you get a code reader to check for fault codes stored on the DSC control unit? That would help us to get a better picture of the issue (sensor, wire short, bad module, etc).

ill try and get the codes read tomorrow. thx for all the help so far!

[mikep]

Originally Posted by apecush

warranty still valid? Sounds like this should be covered....with no diagnostic fee.

no, warranty just ran out in july

[BPMSport]

How is the warranty out already? I thought it was 4 year 50 K...

When did you buy it and whats the mileage?

Start off assistance inactive is just a message on the idrive is not descriptive. You would have to read the codes to see exactly what the problem is. Only someone with the proper equipment will be able to read it since this is not a generic OBD II specific code.

[ec_E92]

Originally Posted by Mike Benvo

Start off assistance inactive is just a message on the idrive is not descriptive. You would have to read the codes to see exactly what the problem is. Only someone with the proper equipment will be able to read it since this is not a generic OBD II specific code.

Not necessarily, a normal code reader should be able to check fault codes stored on the various modules for different systems. ABS and SRS is a different story, but the DSC module should be available? Either way, it's a better investment for the OP than giving to dealer for diagnostics check.

OP see what you got and we'll try to help.

[Blue92]

If this is indeed the "hill assist" portion that has gone out, I'd pay to have mine disabled. This feature has been my biggest headache with the 6MT starting from a stop. It seems that, depending on how hard you were on the brakes when stopped, the release is never quite smooth/predictable. I tend to almost lift completely off the brakes as the car stops rolling in an attempt to keep this PITA "assistant" from kicking in. Having said that; I would not be willing to put up with a fault indication that would not clear. Good luck & let us know the resolution.

[JCtx]

The 'hill assist' only has inputs from clutch and brake switches, but DSC is what actually keeps the brakes applied for up to 2 seconds. What's weird is no DSC error . Keep us posted on your results. Looks like you'd benefit from a Bavarian Tool right now. Good luck.

[MysticBlue]

The fact that cruise control is also acting odd says to me it's maybe a speed sensor with intermittent issues. But, that's just a WAG, because I would think there would be other warning lights that would also come up if that were the case. Interested to see what this turns out to be.

[BPMSport]

Originally Posted by ec_E92

Not necessarily, a normal code reader should be able to check fault codes stored on the various modules for different systems. ABS and SRS is a different story, but the DSC module should be available? Either way, it's a better investment for the OP than giving to dealer for diagnostics check.

OP see what you got and we'll try to help.

Incorrect. A standard OBD II code reader will ONLY check for faults stored in the DME. All other modules would need to be read out using a BMW specific tool - this includes EGS faults (transmission), DSC faults, ABS faults, etc.. Start off assistance inactive is not an engine related (DME) fault. It could be a faulty sensor/signal or an upset module.

[mikep]

hello all,

I finally ordered a bavarian technic cable and got the code.

see new thread

http://www.m3post.com/forums/showthread.php?t=1012553

[mikep]

The solution:

FYI it was the speed sensor (cluster) that was the problem. I found it hiding under the drivers seat, under a painted piece of the body, just forward of the under seat speaker. Relatively easy replacement, just had to disconnect the battery to avoid airbag BS, remove the drivers seat (but not the wiring harness, just leaned it back), remove the under seat speaker cover (no need to remove the speaker), pull the carpet and some of the foam away, remove the three bolts on the bracket and wiggle it out towards the front of the car. It must come out forward because of the way the wiring harness fits on it.

I smashed the old sensor open with a hammer (glued closed) as it was just a dumb circuit board so really no way to figure out wtf happened in there, although I can't really think of a worse place to stick electronic sensors due to risk of getting wet through the carpet on rainy or snowy days.

Bought mine off ebay for $160.

So I saved myself -

Dealer diagnostics minimum: $100
Dealer parts: $640
Dealer labor - quoted 3 hours LOLZ (literally will take you 30 mins or less now that you know where it is): 3x$140/hr = $420
Dealer shop supplies shake down fee: Maybe $40

TOTAL DEALERSHIP RIP OFF would have been $1200+tax!

Dam I deserve a beer.

[///M Power-Belgium]

Originally Posted by mikep

The solution:

FYI it was the speed sensor (cluster) that was the problem. I found it hiding under the drivers seat, under a painted piece of the body, just forward of the under seat speaker. Relatively easy replacement, just had to disconnect the battery to avoid airbag BS, remove the drivers seat (but not the wiring harness, just leaned it back), remove the under seat speaker cover (no need to remove the speaker), pull the carpet and some of the foam away, remove the three bolts on the bracket and wiggle it out towards the front of the car. It must come out forward because of the way the wiring harness fits on it.

I smashed the old sensor open with a hammer (glued closed) as it was just a dumb circuit board so really no way to figure out wtf happened in there, although I can't really think of a worse place to stick electronic sensors due to risk of getting wet through the carpet on rainy or snowy days.

Bought mine off ebay for $160.

So I saved myself -

Dealer diagnostics minimum: $100
Dealer parts: $640
Dealer labor - quoted 3 hours LOLZ (literally will take you 30 mins or less now that you know where it is): 3x$140/hr = $420
Dealer shop supplies shake down fee: Maybe $40

TOTAL DEALERSHIP RIP OFF would have been $1200+tax!

Dam I deserve a beer.

After 3 years you deserve more than one beer !
Good to hear about the solution

[mikep]

part number was 34 52 6 781 575

[BlueF36]

Just ordered that part online today. I'm praying that its going to be the resolution to my issue that sounds identical to yours. If not.. its a waste of money but at least I tried.

Thanks for the great description of your resolution!