What was the problem?
This Audi A3 had a flashing light on its dashboard (engine management system warning light) so came in for a diagnostic test.
A diagnostic test was carried out and the diagnosis revealed a faulty ECT sensor.

What does this mean?
The Engine Coolant Temperature Sensor (ECT) tells the computer the temperature of the engine so that the computer can allow more fuel to be injected into the engine, or less, according to the temperature.
If the ECT sensor becomes defective, then the ECU (Electronic Control Unit: ie, the car’s computer) will receive the wrong information concerning the temperature of the engine.
In severe cases, the engine may not start, or the engine can use too much fuel, causing high fuel emissions.