Hi,
My ST170 has developed an intermittent fault which only happens when the car is cold. I’ve seen this twice now.
I have checked the water level in the expansion tank and its fine + this only happens when the car is cold/left overnight.
So it can’t be over heating, if I switch the engine off and then back on the light goes out and the car runs fine.

I’m guessing the Water\Coolant Temp sensor is faulty – anyone else had this problem.?
Any idea where the Water\Coolant Temp sensor is located.?

The problem: The Multi-Function warning light comes on and initiates the ‘Fail Safe Cooling System’ cuts the engine power fueling, and it sounds like its misfiring.

I have checked the manual, and it’s says on page 143 of the ST170’s owner manual.
The Multi-Function warning light comes on if the car overheats or the water supply becomes depleted. Or if the Auto transmission oil is low - ST170 manual box, so it’s got to be Water\Coolant related.

If water or engine temp continues to rise. “the system will alternate fuelling to the engines cylinders. The disabled cylinders then act as air pumps and help cool the engine”. The vehicle will continue to operate but will have limited engine power.

Thanks,
Manoj