[orbE46]

Last Thursday, on a cold start, I had an error appear: "Chassis Stabilization: Drive Moderately" accompanied by the tri-fecta of DSC/ABS/Brake lights. They went away after a minute, but immediately after the error message came back but only with the DSC light lit. Had the same initial message on about every other cold start since Thursday.

However, yesterday, the "Drivetrain malfunction: reduced engine output" came up for a split second then went away. This message came back just a few minutes ago when I was parking the car (along with Chassis Stabilization), but didn't go away until I shut off the car.

Engine seems to run fine. 2016 340i with 39k. I have an appointment with the dealer to diagnose this week, but has here anybody encountered something similar? Searched around and couldn't find anybody else with both errors occurring. kinda bummed out honestly...

[ozymandias435]

Originally Posted by orbE46

Last Thursday, on a cold start, I had an error appear: "Chassis Stabilization: Drive Moderately" accompanied by the tri-fecta of DSC/ABS/Brake lights. They went away after a minute, but immediately after the error message came back but only with the DSC light lit. Had the same initial message on about every other cold start since Thursday.

However, yesterday, the "Drivetrain malfunction: reduced engine output" came up for a split second then went away. This message came back just a few minutes ago when I was parking the car (along with Chassis Stabilization), but didn't go away until I shut off the car.

Engine seems to run fine. 2016 340i with 39k. I have an appointment with the dealer to diagnose this week, but has here anybody encountered something similar? Searched around and couldn't find anybody else with both errors occurring. kinda bummed out honestly...

I have had this issue twice now on my 2015 435 GC. Both times for me it has been the ABS Wheel Speed sensor. First time it was the passenger rear, then about 4 months later the passenger front. I had the exact same symptoms that you did. I would suggest buying a good code reader and seeing exactly what codes get pulled. If it is in fact the wheel speed sensor they are around $100 and extremely simple to install yourself! These wheel sensors seem to fail a lot based on my research when I had this problems. Hope this helps

[eluded]

Wife wondering why this is our last German car.

[jh_f30]

If you're not noticing any performance or drivability problems, maybe try checking your battery voltage before starting your car. I've read that when the battery starts to go, it can trigger a bunch of warning lights.

Do you have an OBD-II code reader handy? Either a standalone unit like the ones from Foxwell or Schwaben, or an app like BimmerLink on your phone with a wireless OBD-II adapter will let you see what codes are being thrown and possibly help narrow down what the issue might be.

[Billfitz]

Originally Posted by ozymandias435

I have had this issue twice now on my 2015 435 GC. Both times for me it has been the ABS Wheel Speed sensor. First time it was the passenger rear, then about 4 months later the passenger front. I had the exact same symptoms that you did. I would suggest buying a good code reader and seeing exactly what codes get pulled.

+1, the exact same thing happened to me. Everything that relies on speed sensor data to function, from the brakes to the cruise control, in my case even the auto deploy spoiler, will throw a code if a sensor isn't working. It only happened to me once, two years ago, and it must have been an intermittent glitch, as it hasn't happened again. Luckily I had already bought a Foxwell NT510, so I was able to clear the codes, identify the left rear speed sensor as the source, and then verify the speed sensor was functioning. That one use saved me a trip to the dealer, which paid for the tool. I now carry it in the car, in case I need to clear any codes while away from home.

Wife wondering why this is our last German car.

Virtually all recent model cars have ABS, which means they all have speed sensors, so they all can have the same problem.

[ozymandias435]

Originally Posted by Billfitz

+1, the exact same thing happened to me. Everything that relies on speed sensor data to function, from the brakes to the cruise control, in my case even the auto deploy spoiler, will throw a code if a sensor isn't working. It only happened to me once, two years ago, and it must have been an intermittent glitch, as it hasn't happened again. Luckily I had already bought a Foxwell NT510, so I was able to clear the codes, identify the left rear speed sensor as the source, and then verify the speed sensor was functioning. That one use saved me a trip to the dealer, which paid for the tool. I now carry it in the car, in case I need to clear any codes while away from home.
Virtually all recent model cars have ABS, which means they all have speed sensors, so they all can have the same problem.

When I would clear the codes they would just come right back so I had to go ahead and replace the sensors. Codes cleared themselves right after and have perfect since. I do have two new sensors for the driver side in case they want to crap out lol.

[orbE46]

Thanks for the advice guys. Two more observations today:

-When pulling out of a parking lot, brake pedal was initially very hard (while driving, not just like when you start it) and there was a high-frequency light pulsing on the pedal.
-Brake pedal was normal after 2 more stops, but then Drivetrain malfunction came up.
-Sport mode is not allowed when one or both of these malfunctions are present. Assuming that's by design and not another underlying issue?

The pedal thing kind of scared me, braking power was definitely reduced and I have no idea what the ABS system was trying to do. At any rate I have warranty remaining so I'll update with the dealer's findings tomorrow.

And I definitely need to get proper scanning equipment for the car. My understanding is all my E46 diag programs (INPA, PA Soft, Tool32) won't work on this car.

[ozymandias435]

Originally Posted by orbE46

Thanks for the advice guys. Two more observations today:

-When pulling out of a parking lot, brake pedal was initially very hard (while driving, not just like when you start it) and there was a high-frequency light pulsing on the pedal.
-Brake pedal was normal after 2 more stops, but then Drivetrain malfunction came up.
-Sport mode is not allowed when one or both of these malfunctions are present. Assuming that's by design and not another underlying issue?

The pedal thing kind of scared me, braking power was definitely reduced and I have no idea what the ABS system was trying to do. At any rate I have warranty remaining so I'll update with the dealer's findings tomorrow.

And I definitely need to get proper scanning equipment for the car. My understanding is all my E46 diag programs (INPA, PA Soft, Tool32) won't work on this car.

I wouldnt stress too much until you see what they have to say. It sounds just like the ABS sensor problem so hopefully that is what it is. Just dont push the car hard and avoid braking too hard until get it sorted.

Yes it disables sport mode to try and keep the engine from being pushed too hard.

[orbE46]

Thanks guys. Turned out to be the left rear wheel speed sensor. If they’re known to go bad often on these cars fortunately that’s not something tough to DIY. Done several on the E series cars and it looks identical.

[ozymandias435]

Originally Posted by orbE46

Thanks guys. Turned out to be the left rear wheel speed sensor. If they’re known to go bad often on these cars fortunately that’s not something tough to DIY. Done several on the E series cars and it looks identical.

Glad thats all it was. Cheap and easy fix!

[as100]

Originally Posted by orbE46

Thanks guys. Turned out to be the left rear wheel speed sensor. If they’re known to go bad often on these cars fortunately that’s not something tough to DIY. Done several on the E series cars and it looks identical.

How did you diagnose the issue? Code scanner?

[webdeemo]

I have the same problem, i think i will check that sensor. Thanks.

[capt_slow]

Originally Posted by orbE46

And I definitely need to get proper scanning equipment for the car. My understanding is all my E46 diag programs (INPA, PA Soft, Tool32) won't work on this car.

Install ISTA+ on your laptop and get a ENET cable.

[dís_f30]

Wheel speed sensor