Check code 4

[Slugsie]

Just doing some things on my Surf, and decided to do the diagnostic. The code came back as a 4, which is Coolant sensor. Now, I'm guessing that this is something I should be worried about. However, the temperature gaugue appears to work, it starts off at cool when first starting, and slowly works it way up to halfway up the gauge. It's never gone higher than that. The car has had a modified head fitted,so it shouldn't overheat. The coolant level appears to be fine.

Is there anything I should check?

[NiftyNev]

This would be the sensor that is connected to the ECU.The temp one on thermostat housing is just a sender and not a sensor.Still have to find it on mine but it is located on block above starter motor about level with no 4 cylinder.From what I hear it controls fueling during cold start and as engine warms up it allows the ECU to alter fuel supply.When my engine is cold and first started the idle is around 1000 RPM and then drops to 750 RPM after a short period.

Neville

[Slugsie]

This would be the sensor that is connected to the ECU.The temp one on thermostat housing is just a sender and not a sensor.Still have to find it on mine but it is located on block above starter motor about level with no 4 cylinder.From what I hear it controls fueling during cold start and as engine warms up it allows the ECU to alter fuel supply.When my engine is cold and first started the idle is around 1000 RPM and then drops to 750 RPM after a short period.

Neville

Thanks for the reply.

On the off chance that it's something left over from a previous problem, I've reset the error code and I'll check it again after I've been out playing today. If the code re-appears then I know that it is a problem.

Just checked, and even on a cold start it idles at a solid 750rpm.

[Slugsie]

OK, back from a 100mile+ trip, including motorway, off-roading and leaving the car idling for 5-10 minutes at a time. Done the engine check and no flashes so all looks good.