Document Information
Location: Body BIW - Active Aero

Topic: Airbrake Warning Message on the driver's display and the airbrake is
inoperative

Condition: During driving the airbrake message is displayed
Diagnostic Trouble Codes:

TCU:

C101B92 Airbrake move time out

€101C92 Airbrake movement implausible

(101A94 Airbrake not holding position

Measure

In the event of an Airbrake Warning Message, please follow the steps below to
diagnose the concern:

1. Connect the MDS and save a copy of the TCU actual values in .pdf before you
proceed to the next step.

2. Check that the TCU software installed is on the latest 14MOS99CP.16 for MY18,
or 14MO999CP.22 for MY19,

3. If not, update the software of the TCU with MDS.

4, Remove the Airbrake Panel and disconnect the CHMSL (light). Refer to SIS DA-
RM-02A053-03-001 - Remove/Install panel - Airbrake

5. Remove the two M4 bolts (both actuators) from the Position Sensor. It is likely
the Position Sensor has already been glued to the Drive Connector / Actuator Pin
(this should be true of vehicles manufactured from May 2018) and cannot be
independently removed, please continue to Step 10. If the Position Sensor can easily
be removed, continue from Step 6.

M4 Bolt

Position Sensor

Drive Connector
Actuator pin

6, Remove the Drive Connector (if not already removed) while keeping the Actuator
Pin still assembled to the airbrake mechanism.

Drive Connector

7. \nspect and clean any debris or glue residue from the Drive Connector

8. Apply “super glue” (e.g. Loctite 406) to the internal surfaces of the Drive
Connector, see image below

9, Install Drive Connector onto Sensor, ensuring any glue squeeze out does not stop
the Actuator Sensor from functioning (rotating). While the glue is still wet on the
inside of the Drive Connector (add more glue if necessary), reinstall the sensor to the
airbrake mechanism ensuring a good fit with the drive connector

10. Correctly align the Actuator Sensor (with the sensor cable extending out the top
of the sensor) and re-tighten the 2 x M4 screws to 4Nm +/- 0.5Nm

11. Re-assemble the airbrake panel and brake light connector

Care Point: Do not induce any push or pull forces (tension) between the 2 actuators
once the airbrake panel is fixed on them. This can alter their internal friction
characteristics and affect their relative movement speed.

12, Replace airbrake panel fixing bolts every time they are removed. Tighten and
torque to 14Nm +/-1.4Nm following below sequence A - F.

Ce

Fe SO
13, Run the airbrake bleed sequence in TCU. Repeat the sequence 3 times sleeping
the car between each bleed

14. Run the calibration sequence. Once the calibration is completed check the
following actual values - those are the calibrated values

vRearWingLift2MinLH - the value range should be between 0.00 to 9.99
vRearWingLiftlMinRH - the value range should be between 0.00 to 9.99
vRearWingLift2MaxLH - the value range should be between 147.00 to 152.00
vRearWingLiftlMaxRH - the value range should be between 147.00 to 152.00

The airbrake position sensor tolerances are the following:

Sees

Minimum lift (0%) 0.00 mm 0.00 mm 9.99 mm
Maximum lift (100%) | 147.00 mm 152.00 mm 152.00 mm

If the position sensors are still outside the above specification, continue with Step 15
to replace the sensors, pins and connectors. If this has not solved the issue, please
raise a Technical Request and provide all the information requested in this KA.15.

15, Remove the Airbrake Panel and disconnect the CHMSL (light). Refer to SIS DA-
RM-02A053-03-001 - Remove/Install panel - Airbrake

16, Remove the two M4 bolts (both actuators) from the Position Sensor

17. Remove the grub screw (access from the rear of the airbrake mounting plate)

Airbrake mounting
plate

Grub screw

18. Push the actuator pin from one side to slide it out from the other side of the
airbrake mounting plate

19, Replace actuator pin and drive connector using parts from kit (14A0082CP) and
Position Sensors (14A0434CP)

20, Locate the airbrake mounting plate back on the top of the actuator and align the
holes so that the new actuator pin can be inserted through smoothly

21. Reinstall the actuator pin. The flat surface of the pin should be facing up and
slightly towards the rear of the car - see picture below. This will ensure that when
the actuator pin is fully inserted the grub screw threads will be visible and aligned
with the hole at the back of the airbrake mounting plate to allow the grub screw to
be re fitted

Care Point: When re-inserting the actuator pins, ensure the 2 top hat spacers are in
place. If they are not present please order the airbrake repair kit from SPC - part
number: 14A0082CP

22. Once in place push the actuator pin back in position

23, The threads for the grub screw on the side of the actuator pin will now be aligned
with the hole at the back of the airbrake mounting plate

24. Tighten the grub screw to secure the actuator pin in position to 2.5 Nm +/-
0.3Nm

25, Go back and continue from Step 6-14.

Parts Information

N/A
Warranty Information

Resolution Category
Casual Part Number: 14A0434CP
Casual Part Name: POSITION SENSOR VARIOHM VERT X

Casual Issue: Modification