Driving 55mph down a 2 lane country highway on cruise control and suddenly get a grabbing feeling from the front end as if traction control kicked in for no good reason, and immediately both the atc and brake lights come on and stay on. I pull over, check out around the front end, nothing obvious, stop the engine, restart and lights are off. Drive another 40 miles, happens again. I'll get it hooked up to a computer when I'm back home but right now visiting family 100 miles away. Searched the forum, didn't see anything similar.
Thoughts?
Assuming that this happened on a BMW Z3 and not a Lexus, good odds that it might be the yaw sensor failing. It's under the drivers seat, and you can get good used ones on eBay.
Marty
2002 z3 2.5i roadster yes, sorry forgot to mention that important detail.
No codes. But some further interwebs searching seem to align with your guess. Thank you. Where is the sensor on the z3, in front of the driver seat under the carpet?
Some forum posts pointing to the yaw sensor:
http://www.bimmerfest.com/forums/sho...7&postcount=13
http://www.bimmerfest.com/forums/sho...d.php?t=280947
http://www.bimmerfest.com/forums/sho....php?t=1263934
http://www.bimmerforums.com/forum/sh...1#post28687531
https://www.ecstuning.com/b-genuine-...r/34526864094/
BMW MOA 696, BMW CCA 1405
The yaw sensor is right under the middle of the seat; I simply removed the seat (pretty easy once you figure out how to disconnect the electrical connections), disconnected the harness, unbolted the old sensor, installed the new and reconnected the harness, then reinstalled the seat.
Marty
It sounds like the yaw sensor, but I wouldn't go about throwing parts at it without a diagnostic scan.
-Abel
- E36 328is ~210-220whp: Lots of Mods.
- 2000 Z3: Many Mods.
- 2003 VW Jetta TDI Manual 47-50mpg
- 1999 S52 Estoril M Coupe
- 2014 328d Wagon, self-tuned, 270hp/430ft-lbs
- 2019 M2 Competition, self-tuned, 504whp
- 2016 Mini Cooper S
I can not believe people are recommending replacing an extremely expensive sensor blindly based on random searches. Step 1 is to identify which lights are on, and which are not. BMWs do not have ATC lights. ABS, DSC, BRAKE. Which ones are on? Which ones are not? IF you have a BRAKE or ABS light, then it is not the yaw sensor as it';s not part of the brake system. Second, and this is important. READ THE GODDAM CODES!! Don't guess. Don't use a toy OBD2 scanner that only talks to the engine. Set up INPA and have a chat with the ABS module. If a light in it's jurisdiction came on, there will be a code.
/.randy
Ok ok.
BTW it's the exclamation mark with arrow circle light and the brake light. I was only calling it what it says in the manual.
I will do more diagnostics.
That's the ASC + Brake warning lights:
ASC + Brake Warning.jpg
For which these posts seem to apply:
"DSC and Brake light stay on...Solution:Rotational Rate Yaw Sensor Under seat is malfunctioning
Part Number 3452 6 754 289"
https://www.bimmerfest.com/forums/showpost.php?p=4481577&postcount=13
"DSC light & Brake light came on... read a code... l-5E 38 YAW RATE SENSOR ELECTRICAL FAILURE"
https://www.bimmerfest.com/forums/sh...d.php?t=280947
- - - Updated - - -
Some people may find it easier to buy a scanner for the SRS, ABS and ASC modules, like:
https://www.amazon.com/dp/B074WMK67L..._t3_B00DF8BTHC
INPA requires a laptop with an older Windows system, maybe some cables and adapters, and a learning curve:
http://www.bimmerforums.com/forum/sh...xperimentation
http://www.bimmerforums.co.uk/forum/...tarted-t85220/
BMW MOA 696, BMW CCA 1405
Yes, but this rides on the assumption that yaw sensor is the only component that can cause both lights to come on. We're talking about a $1000 part new, or ~$200 used. No way I would do that without a scan, with any tool that will get you some sort of BMW codes from the DSC system.
Picky detail I know, but INPA runs just fine on latest Windows. Agreed on the learning curve.
Last edited by 328 Power 04; 07-03-2018 at 11:08 AM.
-Abel
- E36 328is ~210-220whp: Lots of Mods.
- 2000 Z3: Many Mods.
- 2003 VW Jetta TDI Manual 47-50mpg
- 1999 S52 Estoril M Coupe
- 2014 328d Wagon, self-tuned, 270hp/430ft-lbs
- 2019 M2 Competition, self-tuned, 504whp
- 2016 Mini Cooper S
Another good reason to install INPA is that a friend with an 01 M Roadster had these lights on too. We hooked his car up to INPA and found a display indicating that the steering was off by about -2. We made sure the steering wheel was straight and pushed the reset button. Not really knowing exactly what we were doing, but knowing the value should be 0, we were pleased when the unwanted lights went out and have not come back on.
2002 M Roadster, Steel Gray Metailic, Gray Nappa Leather, Black Soft Top, Steel Gray Metailic Hard Top, TC Kline Double Adj Shocks with H&R Springs, Stromung Exhaust, SSR Type C Wheels. Looking for a new home.
2022 Z4 M40i, Misano Blue Metallic, Prem Pkg, Driver Assistance Pkg
2023 X5 M50, Phytonic Blue, Black Extended Merion Leather, Driving Asst Pro Pkg, Park Asst Pkg, Exec Pkg, Climate Comfort Pkg.
No, but if it is your yaw sensor, it could be dead or just out of adjustment. If it is out of adjustment, then your car is receiving bad data from the sensor and your car is trying to correct for something which isn't happening. What your car is seeing could be different from my friends and depending on the data your car may be doing something different from my friends. My point is, if you think the sensor is bad, it is much less expensive to reset it than to replace it. It may not do anything for it, but then again, it could save you a bunch of money if it just needs to be reset.
2002 M Roadster, Steel Gray Metailic, Gray Nappa Leather, Black Soft Top, Steel Gray Metailic Hard Top, TC Kline Double Adj Shocks with H&R Springs, Stromung Exhaust, SSR Type C Wheels. Looking for a new home.
2022 Z4 M40i, Misano Blue Metallic, Prem Pkg, Driver Assistance Pkg
2023 X5 M50, Phytonic Blue, Black Extended Merion Leather, Driving Asst Pro Pkg, Park Asst Pkg, Exec Pkg, Climate Comfort Pkg.
I guess resetting is a lesser procedure than recalibrating.
Interesting Post #373 here with a PDF on recalibrating the yaw sensor using INPA Tool32 --
https://www.bimmerforums.com/forum/s...9#post29437829
Last edited by Vintage42; 07-04-2018 at 06:26 AM.
BMW MOA 696, BMW CCA 1405
Yes, I think the reason resetting worked in this case is because (we think) an alignment sometime in the past, put the steering wheel just a bit off center. Not enough to cause the sensor to act up at that time, but over time it must have slipped over the point where it did make a difference and caused the lights to come on. The sensor was still calibrated, but the wheels were just a bit off causing the sensor to think the car was going into a slide.
2002 M Roadster, Steel Gray Metailic, Gray Nappa Leather, Black Soft Top, Steel Gray Metailic Hard Top, TC Kline Double Adj Shocks with H&R Springs, Stromung Exhaust, SSR Type C Wheels. Looking for a new home.
2022 Z4 M40i, Misano Blue Metallic, Prem Pkg, Driver Assistance Pkg
2023 X5 M50, Phytonic Blue, Black Extended Merion Leather, Driving Asst Pro Pkg, Park Asst Pkg, Exec Pkg, Climate Comfort Pkg.
Has not happened again in 1000 miles. Thinking do nothing until it's more frequent. Risky?
I'd run inpa and pull the code. Like Able said it could be a number of things. You won't break anything waiting but it can be a little un-nerving when it randomly kicks in. My 99 had the same lights come on and it set a code for ABS pump fail due to a broken solder trace on the ABS module. Your ABS is different so probably not the same issue you're having but still pull the codes through INPA to get to the bottom of it.
Last edited by z3forlife; 08-20-2018 at 11:14 PM.
I highly recommend installation of INPA. It will probably save you some headaches on this repair and if not, you'll have it for when the next light comes on.
Don't be intimidated by the magnitude of the instructions at
http://www.bimmerforums.com/forum/sh...xperimentation.
Most of what you see there are specific questions from dummies like me trying to sort out some detail you'll never experience.
Just follow the instructions on the first post and you'll probably have it up and running in an hour or less. I'm no computer geek, and I did it. If you have trouble, it seems that Abel is always around to answer your questions - he worked me through one glitch with my installation (operator error).
I'll echo the suggestion to get INPA set up.
I had Traction Control + Brake + ABS lights come on in my M5. I would not have been able to diagnose the problem without INPA. I would have simply thrown parts at the car blindly.
Using the live data feature, i found that all sensors were reporting in correctly and the code the car was throwing, the brake pressure sensor code, was erroneous.
Upon doing some research and applying some logic, it turned out the entire ABS unit was defective. That's a common failure on e39 M5 because the unit is directly next to the 5L V8 and 20 years of heat cycles go to it.
I sent it out to a company on ebay that repairs ABS units, they deemed it beyond repair, and I sourced a used one for $80. I then used INPA to code the unit to the car and align the steering angle sensor.
Free software, live data, the right part, $80, and the ability to code everything myself was indispensable.
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