Good evening all I've got a 2012 1.6 hdi At 93000 on clock fan would not switch off so changed coolant temp sensor that sorted it,at 97000 had cam belt and water pump changed but fan will not go off for love nor money so had temp sensor changed again and the fan relay but still it stays on I use it daily at 
least 80 miles a day so not many short journeys any ideas please ?Tia

Does it have aircon?

Worth trying a battery disconnect for 10 mins and see if it resets itself. Does the temp guage read properly?

(07-06-2020, 08:08 AM)cancunia Wrote:  Does it have aircon?

Yes it's got aircon

(07-06-2020, 09:31 AM)Zion Wrote:  Worth trying a battery disconnect for 10 mins and see if it resets itself. Does the temp guage read properly?

Temperature stays the same just below half way will disconnect battery and give that a go ?

Does the gauge always read that value as soon as you turn on the ignition, or does it seem to reflect the proper engine temperature when cold? Trying to figure out if the CTS is actually working

(07-06-2020, 12:05 PM)Zion Wrote:  Does the gauge always read that value as soon as you turn on the ignition, or does it seem to reflect the proper engine temperature when cold? Trying to figure out if the CTS is actually working

It slowly moves to that position like before when fan didn't stay on

ok cool, so weirdly it can't be the CTS triggering the fan, and the fan comes on with ignition now? I'd be wondering about the fan control relay or a fault on the ECU but you tried the relay so can't be that.

My thoughts are:

1. Do a BSI reset. Battery disconnect may fix it anyway but if not do a full BSI reset and see what happens.

2. Check you have no water ingress into the BSI

3. Check and clean the ECU plugs and refit them. Use alcohol cleaner or switch cleaner, not wd40 or anything like it

(07-06-2020, 12:41 PM)Zion Wrote:  ok cool, so weirdly it can't be the CTS triggering the fan, and the fan comes on with ignition now? I'd be wondering about the fan control relay or a fault on the ECU but you tried the relay so can't be that.

My thoughts are:

1. Do a BSI reset. Battery disconnect may fix it anyway but if not do a full BSI reset and see what happens.

2. Check you have no water ingress into the BSI

3. Check and clean the ECU plugs and refit them. Use alcohol cleaner or switch cleaner, not wd40 or anything like it

Ok thankyou will give these a try

The fan will be on when the aircon is on. Just a thought.