Accelerator pedal adjustment and engine temperature Sensor

VALJEANLK

MEMBER
2008 TOYOTA YARIS
1.0L
FWD
MANUAL
70,000 MILES

Hi,
Today, I have two questions on my second hand car (UK version).

Question 1: My accelerator pedal slightly loose and not sensitive, as I need to press the pedal about 1/3 down to floor mat for the car to start react. I tried but I failed to find the throttle cable. Can you advise me where it is in my car? Does my car use throttle cable for accelerator?

Question 2: I recognized that the radiator fan in my car has never rotated since I bought it three weeks ago. Today, I used an ECU scan tool, name Autophix bought in Amazon, and it has shown that the Engine Temperature increased up to 84 Celsius degree only even I drove in a long distance to test. There after, I disconnected the engine temperature sensor then the fan rotated and stopped when I reconnected the sensor. The temperature in Galway, Ireland here is quite low (about two to five Celsius degree). So, do you think this 84 degree of temperature is normal with this weather? My feeling is that the sensor might be broken that why it cannot read higher temperature from engine?

Thank you for reading my post.
Valjean

4 Replies

CARADIODOC

MECHANIC
33,910 POSTS

Your engine uses the "throttle-by-wire" system so there is no simple, reliable cable, and nothing to adjust. The first thing I would do is find a similar car on a used-car lot, and see if the accelerator pedal feels the same as yours. This system put Toyota in the news a few years ago. They did not find a reason for the sudden acceleration complaints, but I do not know if there was a recall or if there was some modification they might have done. If other cars do not feel the same as yours, the pedal assembly will need to be replaced. No mechanic will risk a lawsuit by trying to repair the assembly.

The fact the radiator fan turned on when you unplugged the coolant temperature sensor proves the system is working. That is a fail-safe, or back-up strategy the Engine Computer uses to prevent overheating when it does not know the exact engine temperature. Be aware that temperature sensors have an extremely low failure rate because there is just a single component in them. Almost all failures involve some type of mechanical damage to include corroded connector terminals.

Radiators for the last twenty or more years are extremely efficient. The fan is not needed at low speeds because natural air flow is sufficient. When standing still and idling for a long time, the fan may not be needed in cold weather. You can view live data on a scanner and see exactly the coolant temperature the Engine Computer is seeing. Most radiator fans turn on at around 95 degrees Celsius, which I believe is around 210 degrees Fahrenheit. On a few models, the fan does not turn on until well over 220 degrees F. Which is well above the boiling point of water. I am in the northern U.S. And my electric radiator fan can go all winter without turning on once, even when sitting in stop-and-go traffic. So far nothing you described suggests there is a problem with your fan.