Hello people. Can anyone tell me if a faulty coolant temp sensor will cause the car to idle at about 1500rpm or have I got a sticky valve somewhere. Cheers. Paul.

 

I think a faulty coolant sensor can cause safety boost.

 

I have a "Tunefull Idle" which is cured by wiggling wires around my Throttle Position Sensor. This might be the same thing.

 

Check on TT net as I think there is a Tech on checking your idle, I think Nissan were looking for the most complicated way they could keep a car at idle.

 

If your are still stuck I have some stuff I downloaded that might help.

 

If you are lucky a faulty coolent sensor will be picked up by the ECU and give you a code 13, but that is not always the case.

 

My car's ECU is running code 55 (all ok) but only running 6 psi of boost which I beleive is safety boost. So looking into this on Saturday.

 

ta

 

Eddie ;-)

 

Hi Paul,

 

Have you had the battery off recently? The reason I ask is that once the ecu loses power for about 20 mins it resets and has to learn the characteristics of the air flow meter etc.... The idle will be high for quite a few miles if this is the case...

 

Andy

 

Hi Paul

 

If you are going to replace it the cost is not too bad. I have just bought one and it was £18.50 . I did read somewhere on the net that if this sensor is shot the ecu thinks the engine is cold so raises the idle to compensate (not sure if this is the case).

I am sure one of the guys can give you a more detailed answer!!

 

Seez ya

 

Simon H

 

There are two temp sensors. One for the ECU and one for the temp gauge (both close together). If the one going to the ECU is faulty then the car will run awful. The ECU will behave as though the engine is permanently cold and will run very rich when the engine warms up (Idle will be higher because of increase of fuel). If the engine still pulls smooth then its not the sensor. The way to check is to pull the sensor off whilst the engine is warmed up and running (be carefull of the fan) and see if you notice any difference. No difference = faulty sensor.

 

Do a diagnostics and check for error codes. Also do a voltage check on the TPS. Easy to do.

 

The ECU can take a few hundred miles to re adjust the idle if the battery has been disconnected.

 

There is a screw on the air idle regulator (can't remember its true name) that can be used to adjust base idle.

 

The best way is to plug in a Consult and adjust it to what you want! Matter of seconds to do this.

 

Andy