1 Some 1985 XU series engine models have an oil level sensor fitted to the engine sump, together with a warning lamp on the instrument panel. The system was only fitted on the 1985 model year, and has been deleted from later models.

2 The sensor incorporates a high-resistance wire, which varies in conductivity depending on whether it is immersed in or above the oil.

An electronic control unit mounted under the right-hand side of the facia monitors the conductivity, and operates the warning lamp when necessary.

3 It should be noted that the system only functions accurately if the car is on a level surface. When the ignition is initially switched on, the warning lamp should light for two seconds. If the oil level is correct, the lamp will then go out, but if it starts to flash the oil level is low.

4 To prevent the system functioning unnecessarily after the engine has started, the control unit is earthed through the oil pressure switch. The level check is made before starting the engine. Some early models are not earthed through the oil pressure switch and on these, the warning lamp may flash if for instance the engine is temporarily stalled and the oil has not returned to the sump.