Oil temp sensor

I have a 2006 Skoda Octavia 1Z2 2.0 TFSI with engine code BWA. According to the VCDS system, there is a fault code showing for the oil temperature/level sensor (G8): ‘000406 Engine Oil Temp. Sensor (G8) P0196 – 004 – Implausible Signal’.

This code remains even when the other fault codes are deleted, but doesn’t show until another fault flags the MIL light. Looking at the output data shows oil temperature at 60°C and oil level at 0.

A contact of mine sent me a diagram (Bosch Esitronic B32.1) showing that the sensor has three wires: one to ground, one via fuse F2.4 and power from the central ECU, and one to the engine management ECU (MED – not sure of the issue).

Where is F2.4? I have checked fuse 4 in the engine bay and in the box at the end of the dashboard and both are OK. Does the sensor send a digital signal to indicate temperature and level? Apart from getting under the car, removing the undertray and physically inspecting the wiring, are there any other checks I can make? Keith

Change the sensor, which should cost about £60. The biggest part of the job is removing the plastic cover on the underside of the engine as the car has to be up on a ramp. Drain the oil by removing the sump plug and remove the thermal jacket on the sump which is held on by three plastic screwin plugs. The sensor is next to the sump plug and is held on with Torx bit screws. Then replace the oil and filter – total oil capacity with a filter change is 4.7 litres. What I failed to say was that I had already changed the sensor, hence the reason for further diagnostics. How many wires are there at the sensor? What colour are they? Keith

There are three wires, but I don’t know the colours. Two of the three sensor wires will be the operational earth/live and the other is the signal wire element.

The sensor is a thermal differential type and uses two thermo-couples in a circuit, which allows both the level and temperature to be read from the same sensor. To do this, it is fed by a controller, which relays the information to the next level. Since the fault is not with the sensor, the other possibilities are the controller or the connections/ wiring. Autodata does not show the location of the controller, but perhaps your Bosch diagram does? Once the controller is located, check the wiring for voltages and continuity between the sensor and controller, then between the controller and the main ECU. On the basis of these results, you can decide whether to replace the controller. Thanks for your help, Dave. The controller is under the dashboard, behind the steering wheel, and has a reputation for stopping the electric windows from working. Keith Then we received this email: The problem was that the vehicle oil regime coding had been incorrectly set. Research has shown me that incorrect coding is quite common as some dealers aren’t conversant with the UK settings. Keith