Picasso Engine temperature fault

Hi. I’m hoping someone could shed some light on this problem?
I have a C3 Picasso 1.6 HDI vtr+ 2011 reg.
Haven’t had any problems until now.
The car has been parked up and not used for just over 2 weeks.
When I started it today it came up on dash engine fault followed by stop engine temperature fault with the temperature symbol staying on in red and service staying on?
I have plugged in a code reader and no codes were found?
I have changed the temperature sensor but it still has the same faults?
Coolant level is good?
Any ideas please would be most appreciated.
Thanks in advance

Hi

You should have codes stored for error messages showing.

Your OBD2 may not be up to the job?

Try lexia clone tool to get a full read for all the information to diagnose the fault.

Has there been heavy rain over those 2 weeks? Do you have any missing plastic covers from the engine bay? Do you think rain water could have got into where it shouldn't?

Thanks for your reply. Yes we’ve had rain and the odd times it has been heavy. The only plastic cover I can see that’s missing is the one with wiring that sits on top of the battery? What thing(s) should I look at and would a BSI reset clear any fault codes as I read somewhere else that if you change the temperature sensor then you would need to clear any codes otherwise it would still come up with faults on the dash? Thanks for your help

The temperature fault should clear itself if the fault has been cleared.

You changed the sensor and that didn't clear the light, so it not the sensor that is faulty.

Should that missing cover for the battery also shield the ECU from rain? I know it does on the classic C3. You may have water in the ECU connector? Disconnect the battery and remove the connectors to check/spray with WD40.

Missing covers for ECU has caused many strange faults in the past.

It is surprising how much water gets in the engine bay, even without driving the thing.

A BSI reset won't do any harm. You won't need to re-code the radio or anything like that.