Ecu cleaning

[Peggy207]

Evening all,just a quick question,I have been told I need to replace my ecu after having my thermostat replaced, mechanic told me as the temperature gauge keeps fluctuating and have a yellow warning ? light on that also reads engine fault repair needed that it could be the ecu,but my question is what if I buy some wd40 contact cleaner and cleaned it would it work and save me some money? Many thanks.

[RichardW]

On some of these a leak from the temp sensor can track back along the wiring harness, and cause corrosion at the ECU. You would need to get the plugs off the ECU to see if there is any sign of coolant / corrosion.