[rollinstone157]

Hi All -

I'm requesting with my heated steering wheel. I have a 2013 F30 that came with heated steering from the factory. Despite indications on the control display, the heated steering wheel is not turned on by pressing the physical button, but when I run test cycles and read sensor information in ISTA, the heat is triggered and all the tests check out - I'm at a loss!

Observations - Physical Controls

• Physically pressing the heated steering wheel button does cause the steering wheel heating activated and steering wheel heating deactivated messages to show up on the control display.
• Physically pressing the button does not activate the light on the column-mounted heated steering button (more on this later).
• The steering wheel does not actually activate when I press the heated steering wheel button.

Observations - ISTA
I got access to a copy of the ISTA+ diagnostic software and ran a full scan on the car. The heated steering wheel is controlled via the FEM (Front Electronic Module). I ran some tests using the Component Triggering and Diagnosis Scan tabs under the menu Vehicle Information > Control Unit Tree > FEM > Call Up ECU Functions.

• There are no active codes on the FEM

ISTA - Component Triggering
Under the Component Triggering tab, there is a LED, steering wheel heating test item (used to cycle on/off the LED on the heated steering wheel button). There is also a Steering wheel heating test item (this should activate the heat on the steering wheel for 30 seconds).

• Cycling the LED, steering wheel heating test item properly cycles the LED on the heated steering wheel button.
• Activating the Steering wheel heating test item causes the wheel to start heating expected.

ISTA - Diagnosis Scan
There are a few sensors that can be read out under the Steering wheel heating sub-menu on the Diagnosis Scan tab:

• Power consumption, steering wheel heating
• Status, steering wheel heating
• Status, actuator, steering wheel heating
• Steering wheel heating installation
• Steering-wheel heating button

When the tests from component triggering are running ISTA shows

• Power consumption, steering wheel heating = ~6.0 Amps
• Status, steering wheel heating = switched on
• Status, actuator, steering wheel heating = normal state
• Steering wheel heating installation = fitted
• Steering-wheel heating button = not operated

When I try pressing the button on the steering column ISTA shows

• Power consumption, steering wheel heating = 0 Amps
• Status, steering wheel heating = switched off
• Status, actuator, steering wheel heating = Below limit
• Steering wheel heating installation = fitted
• Steering-wheel heating button = operated when the button is pressed, and not operated when the button is released

Final Thoughts and Musings
So, it seems that when ISTA tries to start up the heated steering wheel, everything is fine - when I use the button, no luck. Before getting ISTA, I replaced the button, thinking that a dead LED could be blocking the heat from activating - but no luck.

I will also mention that at one point last winter, I got a low battery voltage warning on a ridiculously cold -20F day in Vermont. I have heard that warning can cause the car to prevent certain functions from activating. I see no stuck codes in ISTA, battery voltage is fine, but do you think it is possible that the car has some "stuck", hidden code that could be blocking the heat that could fixed by resetting battery adaptation or re-coding a module?

My other thought is that the temperature sensor in the wheel could be shot, but I have to assume that one of those five tests above would show some kind of indication.

Any help is appreciated. I am not a dealer, though I will concede my local shop is stumped too.

Any users providing information that leads to the answer will be rewarded with beer money and the solution will be well-documented in this thread for community benefit!

[Siki78]

Send me your cafd from FEM I will compare with mein.

[rollinstone157]

Originally Posted by Siki78

Send me your cafd from FEM I will compare with mein.

Thank you for your offer to help--sending PM!

[rollinstone157]

I wrote the following to Siki78, but thought I would share it here as it might help someone find this thread in the future.

------------------------------------

I just changed the button, not the wiring harness. My initial button did have a dead LED, but I believe that to be coincidental for the time being.

Per ISTA, the wiring harness from the button to the steering wheel cluster has four lines:

• Kl. 31 (Ground Wire)
• SIG (Signal from the steering wheel heating button)
• SIG2 (Activation for function indicator light (steering wheel heating)
• 1 pin not used

Since ISTA can read when the button is pressed and released, pin SIG must be working. Since ISTA can trigger the indicator light on the button, pin SIG2 must be working. In order for either pin SIG or SIG2 to communicate back to the FEM successfully, the ground pin - Kl. 31 - must also be fine... 🤔

Per the "Switch, steering wheel heating" documentation section of ISTA:

If the steering wheel heating switch fails, the following behaviour is to be expected:
Vehicles with Front Electronic Module (FEM):

• Fault code entry in the FEM

The diagnosis system can be used to carry out a function check of the steering wheel heating switch.

Since I have no fault code entry in the FEM and all other button-related tests are passing, I think the issue must be upstream.

Per ISTA:

The steering column switch cluster sends a request to switch on or off the steering wheel heating as a local interconnect network bus message. The FEM forwards this request to the steering wheel module via the LIN bus.

The steering wheel module switches the steering wheel heating on and monitors its function. The steering wheel heating has an NTC resistor. The purpose of this resistor is to control the temperature of the steering wheel
heating.

I think my next step is now to do some more research on this "steering wheel module" and potentially try to test if the NTC resistor is in spec (either through software or a multimeter).

[phat_joe]

How have you been making out on this?

I'm also wondering what conditions led up to this issue. A few questions:

• Please confirm, when was the last time the heating functioned as normal in the car?

• Are other buttons on the steering wheel functioning as expected (e.g., cruise control, media, etc.)?

• Are you able to remove the wheel to physically inspect the components, and if so, could you post pics?

[ypedMN]

Hi rollinstone157 -

First time that I'm posting on this site..

I have a 2017 F30 with the factory heated steering wheel option and have been dealing with the same/similar issue. Basically random / intermittent no heat, even though the control display indicates heated wheel is activated with toggling of the switch.

Ended up taking it to my local BMW dealership to trouble-shoot/diagnose. This is what they found:

1) Faults related to steering wheel electronics (in my case a cruise control fault)
2) Thermal damage to harness terminal/connector and some (minor) damage to the clockspring terminal caused by overloading of the heat circuit. Damaged harness terminal causing random loss of continuity leading to no heat.

They told me this is a known issue but that there's no recall at this time.

Recommended replacing the main steering wheel harness (thermal damage to terminal/connector), steering column control module (likely cause of overloading - a few times earlier this winter I noticed that the steering wheel got unusually hot, which is likely when the circuit overloaded and damaged the terminals) and the clockspring (part of the steering column switch cluster, aka "multi-function switch").

Wanted to charge me US $2,300 - no frikkin' way..

I've identified 2 of the 3 parts needed for my 2017 F30 (sport line w/ paddle shifters, htd. steering, cruise control, rain sensing wipers, w/o lane assist):

- Steering Wheel Wiring Harness - BMW (32-30-9-483-021) ~$70-$75
- Steering Column Control Module - BMW (61-31-7-468-008) ~$240-$260
- Clockspring (part of steering col. switch cluster or multi-function switch) - does not look to be sold separately from the multi-function switch. Not sure if the clockspring is serviceable/replaceable. I'm thinking to skip replacing this. There was only minor thermal damage at the base of the female terminal and it should do as is.

Based on what you've shared and what I've learned, I think the culprit is the Steering Col. Control Module.

My one question to you or the Forum is: will I need to do any coding if I replace the Steering Col. Control Module? Never attempted any coding...

Thanks in advance for any feedback or advice.

[TheNine90]

If you replace it you may not need to code it since the SZL is under the FEM.

[F30ness]

YpedMN - thanks for sharing all this detail! I’m curious how things worked out for you. I’m embarking on a similar task, as my 2015 F30 steering wheel heat no longer works, and I get the occasional cruise control warning.