Audi A6: Adaptive Air Suspension Compressor and Height Sensor Failure

The optional (and fitted as standard on many A6 variants sold in Australia) Audi air suspension uses an electric compressor to maintain air spring pressure and four height sensors to communicate ride height to the control module. The compressor motor brushes wear out and the compressor membrane cracks, while the potentiometric height sensors corrode at their pivot points or suffer wiring harness chafing near the wheel arch. Both faults trigger the suspension warning light and can cause the vehicle to sit noticeably low on one or more corners overnight. Continued driving on a failed compressor accelerates air strut wear.

• Suspension warning light and message 'Suspension fault: do not exceed 80 km/h'
• Vehicle sitting visibly lower on one corner or all corners after an overnight park
• Audible compressor running continuously or for long periods after start-up
• Uneven or bouncy ride quality on one axle compared to the other
• Fault codes for height sensor implausible signal stored in the suspension control module

1. 1

   Inspect the vehicle after it has sat overnight — check all four corners are at equal, correct ride height.

2. 2

   Start the engine and listen for the compressor running for an extended period (more than 30 seconds) to maintain pressure, indicating a leak.

3. 3

   Check the height sensor linkage rods at all four corners for corrosion or play.

4. 4

   Scan for fault codes C10B3, C10B7 (height sensors) and C0795 (compressor circuit).

5. 5

   Check the compressor reservoir under the rear floor for moisture contamination.

Parts involved: Air suspension strut.

≈A$830 to ≈A$4,140 at independent workshop rates, shown as an approximate guide in Australian dollars. That is for this job on its own, not for the car.

An estimate, converted to Australian dollars, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

• “Has the air suspension compressor or any of the height sensors been replaced, and does the system hold ride height overnight?”
• “Has the suspension warning light ever appeared, and has any suspension fault been diagnosed or cleared?”

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.