Discovery 3 EAS faults, decoded

"Suspension fault — vehicle may not restart" is the Discovery 3 message that empties wallets on hearsay. Half the time it is a forty-lev height sensor, not a nine-hundred-lev compressor, but panic and a parts-cannon approach turn a small fault into a big bill. Reading the codes first is the whole game.

What EAS is actually doing

The system holds each corner at a target height using an air spring, a ride-height sensor and a shared compressor with a dryer, all managed through a valve block. When one input drifts or one component leaks, the ECU protects itself by parking the car and lighting the warning. Understanding those five pieces is enough to make sense of nearly every fault it throws.

Common codes and what they mean

Compressor over-temperature or over-run usually means the compressor is working too hard to chase a leak, not that it has failed. Height-sensor plausibility faults point at a worn or damp sensor or its linkage. Slow-leak codes send you to the bags and the valve block. The code rarely names the broken part outright — it names the symptom, and your job is to trace it back.

Fix in the right order

Find leaks with soapy water on the bags, fittings and valve block before you condemn the compressor — most "dead" compressors are simply exhausted by a leak upstream. Calibrate the height sensors after any suspension work. And when the compressor genuinely is worn, a piston-and-dryer rebuild is often better value than a cheap complete unit that arrives already tired.

On EAS the compressor is usually the victim, not the culprit — find the leak that killed it.

Ivan Petrov · Master Technician