Thread: D4 cruise control runs away

Fixed.


Longitudinal Accelerometer Sensor calibration. First I checked everything was securely mounted, I suspect it's been bumped/forced in some way.


Last night I was reading that this sensor is used by the ABS system as a checksum to verify the quality of the wheelspeed values (along with other ECUs) - after reading this, I figured we were on the right path. Ran the calibration and It is now working perfectly.


Thanks All - What Josh has proved is that we all need a "too many can moment" every now and then - its called research.

The method for calibration is:
1 park on level ground - I was pretty sure we don't have any so I laser'd the carport slab and there is 30mm fall across the wheelbase, so 30mm boards went under the rear tyres.
2 park brake on
3 Ignition on
4 press go

What I didn't do was get a live reading first. I've read of others who have a fault code logged for this sensor calibration and on reading live value it is clearly out. I meant to do a read first but forgot....

Love it. Go Josh!

Well I'm on my way to fixing the next unknown issue

Originally Posted by Porker

I had a sphincter tightening experience with my cruise control once, I had the cruise set at 90kph and was travelling along a flat road that started to go uphill with nice little bend at the top, well around halfway to the bend the car kicked down a gear and next thing I know I’m doing over 100kph and still accelerating. I hit the brakes and that dropped the cruise control out it was with some trepidation that I used it again but touch wood I’ve had no problems with it since.

This seems normal if driving in winding hilly terrain with CC it applies Ludicrous Mode and absolutely sinks the boot in and drops a few cogs to maintain pace which has happened a few times to me when the uphill involves a tightening bend you’re scrambling for the brake pedal.

If I have the cruise on and i start to go around a tight bend, the cruise just shuts off. Very annoying as I love to sometimes sweep around tight curves/bends at speed and the car just drops out of cruise. Maybe its a later D4 upgrade????

Originally Posted by dirvine

If I have the cruise on and i start to go around a tight bend, the cruise just shuts off. Very annoying as I love to sometimes sweep around tight curves/bends at speed and the car just drops out of cruise. Maybe its a later D4 upgrade????

Not an upgrade. You have a glitch!
Either a calibration issue or switch/clock spring related issue

yeah... from what I've learned over the last couple days, I would do the calibration process on all 3:
* Longitudinal Accelerometer Sensor.
* Lateral Accelerometer (I suspect this would be the one affecting corners)
* Yaw Sensor