Strange Saxo issue - help / advice please

vince · Post by **vince** » 18 Nov 2009, 21:32

Hi guys,

I had a guy in the shop today who is having trouble with a 51 plate Saxo 1.4. I know we sell parts but i love helping people crack long suffering problems they may have.....so im fishing for the solution to this guys problem as he is calling me back on Friday

So, the car runs fine. idles fine etc. However, every time the car is started from cold...around 10 seconds from ignition the coolant warning light comes on and the fans kick in on full speed. A short while after the needle rests at half way and the car physically runs normal.

The only way to stop the fans is to disconnect them/it. Whilst this stops the fan the coolant warning light remains illuminated. The fan control relay has been checked and Ok'd? and the 2 temp senders have been changed for new ones....the problem continues.

The water pump has also been checked as has the cooling system for leaks.

Either way, i suspect an electrical problem somewhere due to the nature of the fault not being influenced by true engine temp.

The car does not have A/C and is a 2001 Saxo 1.4 petrol....

Ideas guys?

Vince

wheeler · Post by **wheeler** » 18 Nov 2009, 22:37

The fan is controlled by the injection ECU. First thing i would check it's software is up to date. the fact that the fault is the same every time suggests something like that.

vince · Post by **vince** » 18 Nov 2009, 23:06

Thanks Wheeler.....

Sorry for being dumb but if something was amiss would it show on a fault code reading? and also would the coolant light remain illuminated?

I forgot to mention that the customer has had the codes read with no faults found...he also suspects an ECU fault somewhere as he is mechanic and knows hsi way around a car.

wheeler · Post by **wheeler** » 19 Nov 2009, 10:43

I would think it highly unlikley to show any fault codes & the coolant warning would not neccisarily be on. Can he read live data from the CTS ?

Citroenmad · Post by **Citroenmad** » 19 Nov 2009, 10:48

Could it not be a temperature sensor?

My 206 had a failty temp sensor, it would tell me the coolent temp is too high while the car was warming up. When it got to temp it was fine.

Though the problem developed and it would then say the coolent temp its too high all of the time.

wheeler · Post by **wheeler** » 19 Nov 2009, 14:43

both sensors have been replaced already.
If the live data from the sensor is reading ok (which i suspect it is as there are no fault codes) then i would suspect the ECU causing the problem.