Horn Failure / Steering Wheel Controls Partly Inoperative

Horn Failure / Steering Wheel Controls Partly Inoperative







Fault symptoms

The horn does not work and no DTC is present.
Not all steering wheel controls work, no DTC.

Diagnostic help

The horn buttons can be read with the diagnostic tool.
The horn outputs can be activated with the diagnostic tool.

The controls (7 (2416 ohm) or 9 (2512 ohm, Sentronic) resistors in series) are fed with +5 V from the SID. When a button is pressed, the resistor in question is grounded giving a particular voltage.

NOTE: A button has stuck.

Checking the wiring harness

Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short circuits. Check switches, connectors and crimp connections for oxidation, withdrawn pins and pin clamping force.

Fault diagnosis procedure is not available.