The clock spring is attached to the front of the steering column switch cluster as part of the assembly.
It is a flat wire ribbon foil that runs through the clock spring cartridge and connects electrical circuits. The horn, driver airbag, and multi-function switch on the steering wheel, for example.
When the clock springs break, usually the driver’s airbag warning light will illuminate, as well as the multifunction buttons and horn won’t work.
Unprofessional repairs are the most typical cause of clock spring break. When repairing components of the steering mechanism, such as the steering rack or joints, the steering wheel usually spins and breaks the clock spring foil.
Apart from these incidents, I’ve seen broken clock springs on low-mileage cars that have never been touched, particularly on early models.
If you’ve determined that your clock spring is broken, this DIY article will show you how to replace it like an expert.
You’ll need to calibrate the steering angle sensor and clear the fault memory after replacing the clock spring cartridge. You can do the whole thing yourself or just replace the clock spring and take your BMW to a shop for calibration, depending on your skills and tools.
If you don’t have the equipment to calibrate the steering angle sensor, all you’ll need is a good K+DCAN cable, INPA and Toolset 32.
Let’s get started.
Set the wheels in a straight-ahead position and keep them there during the repair.
Disconnect the negative battery lead and remove the airbag.
Remove the shift paddles if installed.
Insert a Torx screwdriver (T25) into the hidden opening on the backside of the steering wheel at an angle until spring resistance is felt (approx. 1in).
Using a Torx screwdriver (T25), increase pressure on the spring leg (concealed) until the airbag unit is freed. Carry on with the same on the other side.
Tilt the airbag backward, disconnect the plug connectors and remove the airbag.
Remove steering wheel
Remove the plug connector (1).
Disconnect plug connection (2) for steering wheel heating if installed.
Remove the steering wheel by removing the third screw (4).
Tightening torque: 46 ft lbs / 63 Nm
Remove steering column upper and lower trim sections
Move the steering column in ”bottom” and ”extended” position. Unclip steering column trim (1) at the side with a trim removal tool.
Unclip steering column trim downwards by pressing detent lugs outwards.
Release screws (1).
Remove the steering column switch cluster (2).
Clock spring cartridge replacement
Unlock catches (1).
Remove the clock spring cartridge (4) from the fastening for the steering column stalk in the direction of the arrow (3).
Please do not turn the ring (1).
It’s also not allowed to rotate ring (1) 360 degrees.
Protect the ring (1) from being turned by anyone who isn’t supposed to be there (e.g. with adhesive tape).
Notch (3) on a ring (1) must line up with arrow (4) on switch (2).
Adjust the clock spring cartridge (1) so that the guide (2) fits perfectly into the switch’s related notch (3).
Install everything in reverse order.
Calibrate the steering angle sensor
You can calibrate the steering angle sensor with ISTA, Toolset 32, or any other scan tool that has this function.
The easiest and fastest way is by using the Toolset 32:
Load your BMW’s DSC_xx.PRG file.
Run the “lenkwinkel_dsc_abgleichen” job with double click.
Clear fault memory
Run the “FUNCTIONAL JOBS” and erase all errors in the fault memory.
Rerun the test (Read EM) to see if the errors have disappeared.