Citroen C3 Cooling Fan Help Please

[den9112]

Hi , I have a C3 2003 with 65k full service history and running great, however I have a issue with the cooling fan not kicking in,i have a open circuit and ECU fault, I have 12v going to the large plug and one 12v going to the block with 3 cables on,it also as AC but I believe that this is in active if the temp gauge hits the red bar, I am not sure which way to go with this , if I leave the car in the garage to try and trace the faulty wire or open circuit the cost could keep rising until it is found,sensors have been  replaced , I quick suggestion from the garage was a modified (retro fan ) fitted , is this possible any could anyone please help out with any ideas as I know as the weather gets warmer it could cause problems .Thanks

[paul.h]

Welcome to the forum.

 

A lot of questions to help with a solution but fitting a stand alone fan would not be the best option since it would need to be integrated with the cars control systems so it works on high engine temperatures and when you want the air con to work.

 

Is the garage you have used a Citroen dealer or specialist with the correct diagnostic equipment ?

 

Have you tried a 12 volt supply direct to the fan motor avoiding its control system to see if it works on its own since it may just need a new/second hand fan ?

 

Can you provide some more details:

- which model and engine is the car

- which sensors have you replaced

- does the fan run when you switch on the air con (the air con will run the fan to cool the refrigerant consenser radiator at the front of the car)

- does the air con work - if not it may be since the fan is not working

- the fan should start when the engine coolant reaches 96°C if it is a 1.4 petrol and this can be checked using a live data code reader

- is the engine temperature gauge showing normal values - 3 bars on the gauge once warmed up

- have you checked the fuses

- have you checked the fan relay - if one is fitted (cars without air con) it will be on the fan shroud according to the Haynes manual

- are the 2 plugs you mention the ones at the fan as shown in the Haynes manual. In the Haynes wiring diagram for petrol and diesel cars with air con it shows the 2 wire plug should have a permanent 12 volt supply from maxi fuse 1 and a permanent earth (this should be checked). The 3 wire plug has a switched 12 volt supply through fuse F8 (engine compartment) and 2 wires from the ecu.

[den9112]

Hi the car is a 1.4 desire sx ,it as air con fitted but that knocks off when the temp gauge hits red,it wont come back on untill the fault is cleared,their is no relay on the fan,i have two blocks on the fan,one with two thick wires and a block with 3 wires in ,both sensors have been replaced and fan checked via bridging the sensor to see if it works which it does it comes on and runs,their is a 12v feed to going in to the fan and a 12v feed to the white wire going in to the 3 wire block,i have no use for AC and was told that fitting a thermo coupling or something like that set to the correct temp to kick in via reading what it should do with live data and using the origanal fan that should do the job,he also said it as been done on a few c3 problem cases with fan problems ,i have no reason to disbelieve him.

[paul.h]

So the problem is that the temperature gauge is going to the max red and the fan is not cutting in. However, the fan has been proved to work  by bridging a temp sensor and it must also be working a bit for the air con to work.  You have not mentioned any signs of the engine overheating.

 

Is the garage a Citroen dealer and the sensors that were replaced, are these the 2 temperature sensors at the end of the cylinder head ?

 

The temperature sensors - one has 2 wires and does the temp gauge and should start the fan at 96°C, the other has 1 wire and just does a high temp alarm at 118°C and should then start the fan. High temperature will cut out the air con to reduce the load on the engine.

 

Is the temperature gauge showing normal temperatures - should be 3 bars once warmed up - or is it going to max and showing red and how quickly does it go to red ? I had this on 2 occasions when our 2003 1.4 C3 went to red but the engine fan did run. First time I stopped the car and let it cool down. The second time was a year later, I did not stop but slowed down, used the cabin heater on max and its blower on max and the temp did reduce. However, I found nothing wrong, did temperature checks using live data, the fan cut in and out correctly. Later though when I replaced the timing belt I also replaced the coolant, water pump and thermostat and the problem did not happen again. So I suspected there may have been a fault with the thermostat although it worked correctly when tested in boiling water.

 

Things to try since this could be just an ecu error:

- use live data to see what temperatures are being indicated by the sensor going to the temperature gauge

- try a battery disconnection and reconnection following the procedure in the Technical Section pinned Common Problems post. Whilst disconnected you could see if the ecu connector pins are clean. However, the fact briding one of the sensors (I am guessing the high temp one) starts the fan suggests this may be ok. If you had bridged the temp gauge sensor connector you would have got a fault code due to the resistance reading being out of range and this would not start the fan, also the same might occur if there was a wiring fault on this circuit.

- consider replacing the thermostat (it should start to open at 89°C).

- consider using a Citroen dealer if not already done.

- you could try a resistor across the temp gauge sensor connector to see if it works, data from the French RTA manual gives 3800 / 2500 / 800 / 230 ohms at 10 / 20 / 50 / 90°C.

[den9112]

Hi garage is not a dealer, on running the diagnostic their was a sensor fault that was cleared, also a open circuit fault to ecu recorded, I must admit that the car as not overheated to date even though it hit the red beep max at the weekend in stationary traffic on the motorway, the car as been running at two bars and only occasionally reaches 3 but when it does it quickly goes back to 2 bars,i have just had a new timing belt and water pump fitted, I also purchased a thermostat today, hopefully I will get time to fit that tomorrow,forgot to add that I did a complete BSI reset,didnt solve the problem but it fixed my radio display after fitting a aftermarket HU so that tells me the reset did actually do its job

Edited February 25, 2014 by den9112

[paul.h]

Until the fan problem is sorted, if the temp gauge does go high I would use the cabin heater and blower on max and have the windows down. The C3 heater is one of the best I have come across so must be able to remove a lot of the engine heat.

 

If you do your own maintenance there are a few points in here http://www.citroen-owners-club.co.uk/citroen/topic/14988-just-sold-vectra-for-c3-maintenance/

 

In it I noted that on refilling with coolant it takes some effort to get the air out:-

If you replace the coolant it is very slow to refill and also get the air out without the header tank as shown in Haynes. I found that applying vacuum to the cylinder head air bleed hole and with the car slightly raised at the left side (where the bleed points are) worked. Vacuum was from a Mityvac brake bleeder with the bleed hose held against the air bleed hole but a syringe may do. On start up though I could still hear some air going round the heater for a short while. There was a post on the C3 subforum where somebody had air going round after changing the coolant.         

[den9112]

Thanks for the info ,

[den9112]

Update on my fan issue, I changed the thermostat today ,refilled with correct coolant then drove the 6 miles home, after approx. 4 miles the temp gauge hit 3 bars and stayed their, usually it as only hit 2 bars, so that was a good sign, however after 5 miles at traveling at 30mph the temp gauge jumped to max red and bleeped ,I continued a few hundred yards and it went back to 3 bars until I got home, when I got home I left the engine running opened the bonnet and topped up coolant approx. 1 litre ,while I did this I noticed the fan going albeit for a few secs then stop and restart again slow then stop, I didn't have time to leave the engine running for to long but I noticed that the gauge was sitting at 3 bars ,my only issue now is whether to believe that the garage as checked the sensor with the single wire that is slightly obscured with a metal guard at the side which looks like it needs removing in order to get to the sensor,i suppose I surmise that the fan does work and their is a connection and not a break in a wire,just had a rethink on the temp hitting max and bleeping on way home,it could be low coolant warning ,will have a better idea in the next day or two if fan is kicking in if it does it will be down to a thermostat sticking open (I hope)

Edited February 26, 2014 by den9112

[paul.h]

When I did the temperature checks on our C3 using a code reader with live data, it showed the fan cut in at 96°C and then stopped when it had fallen down to 94°C. The fan is supposed to be a 2 speed one but I only saw/heard it at one speed and that seemed fast. When using the air con it would start and stop for short periods.

 

The temperature gauge bars cover a wide range of temperature. 2 bars would light at 70°C, 3 bars at 80°C to over 96°C - it would not go over this when tested due to the fan cutting in.

 

Keep an eye on the coolant level since it may take a few days for all the air to come out.

 

If you are thinking of getting a code reader with live data we have a Gendan one which works ok http://www.gendan.co.uk/product_GCR25.html

Other members on this forum have bought a Lexia diagnostic tool which does a lot of the dealer diagnostics and prices seem to be about £100. On the C5 pages there is a pinned post with some members who will help others with diagnostics.

[den9112]

Thanks again or the info,it may take a few days to ind out if the fan is working or not,am i correct in saying that once the temp hits red the air con is automaticaly shut down,if so would i need a BSI reset or a code reader to erase any faults ..as i tried the aircon and the fan didnt come on .

[paul.h]

As far as I know the air con should work again once the temperature comes down without needing any fault codes resetting. The cabin fan has to be on. If the air con refrigerant amount is low this will stop the air con working or it would quickly cut out.

 

A low cost code reader will only read codes on the engine, to see any on the air con will need the dealer type Lexia.

[den9112]

Another update, I travelled my usual 7 miles home this morning ,temp showed 3 bars after a few miles and stayed until I got home ,I put a mark on the fan and the shroud ,took the dog for a 15 min walk and left the engine running ,when I got back I noticed the fan was not lined up with the mark I put on the shroud,i presumed it must have kicked in,i decided to stay and watch and eventually the fan kicked in but when I looked at the temp It didn't  to kick in until it hit the red , it then cooled it back down to three,i suppose I now know the fan is working but I thought it would have kicked in before it hit the red max .

[paul.h]

Our C3 fan would kick in on 3 bars and not get to the red apart from the 2 occasions. You could really do with a live data check on the temperature to see if the sensors are kicking in the fan at the right temperature. If the fan starts at red then that could be from the high temp sensor - which might be doing this at a low temperature due to a fault with it, but it just puts the gauge to red when from the other sensor it may only be on 3 bars.

 

When cooling back down from red did it reduce the number of bars gradually or just jump down to 3 ?

[den9112]

Hi, yest it just dropped  to three,i have been looking for the second sensor on line but all i can find is the two wired green,the one i want is below that with a single wire as i have physicaly changed the top one and i am only going of the garages word that the bottom one is fine....

Edited February 27, 2014 by den9112

[paul.h]

The high temp sensor in the end of the cylinder head is Citroen part no. 024286. A search on ebay gives this http://www.ebay.co.uk/itm/Citroen-AX-C2-C3-C4-SAXO-BERLINGO-XSARA-PICASSO-WATER-TEMPERATURE-SENSOR-NEW-/280892420209

 but I usually prefer to buy parts from a Citroen dealer (using the car VIN) then you know it is the right one, even if it costs a bit more. It should be blue.

 

The temperature gauge one green with 2 wires is part no. 1338A7 and on earlier cars it was a 3 wire one blue 1338A6.

 

You can see the Citroen parts diagrams as a free service on the service.citroen site if you register as another professional, member of the Citroen Owners Club. http://service.citroen.com/do/changerParametres

The high temp sensor can be found under Mechanical, Cylinder head, Cylinder head cover.

[den9112]

Thanks for the info ,that link to the sensor will not fit the 1.4 8v

[paul.h]

Odd since it has the right part no. Here is another one but shows the value of going to a dealer. http://www.ebay.co.uk/itm/NEW-GENUINE-PEUGEOT-CITROEN-WATER-COOLANT-T-0242-86-/151241794858?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item2336b6a52a

[den9112]

Ordered part ,will update when I receive and fit

[den9112]

Update but not without problems ,I will try and go everything that as happened that has given me the engine management light to show ,my initial problem was the fan not working and car running cool, however a new thermostat solved that although gauge hit red before it worked,Ok so now I know fan works so I unplugged the cylinder side sensor(blue)and found that I didn't have a socket to fit ,replugged the sensor and the gauge went to red and fan ran constantly, I parked up and unplugged the fan to stop it running, I then started the car and the engine management light was on and gauge on red and fan running all the time,i then changed the cylinder side sensor and that solved the temp gauge ,now back to three bars and running ok but I still have the engine light on,nightmare of a car at the moment,any ideas on were to go next on this issue .thanks 

[paul.h]

I am guessing you will need the fault code reading and then deleting so the light will go off. So it does look as if the high temp sensor (blue) that you have changed was faulty.

 

Where are you located since there are some members who will help with diagnostics/code reading. There is a pinned post on the C5 section. http://www.citroen-owners-club.co.uk/citroen/topic/20345-diagnostic-help/

[den9112]

Hi thanks for the Link ,no one in my area ,I work in Rochdale and live in Shawforth ,I was looing at some Lexia but I have heard the software can be a nightmare to install.

[den9112]

Another update which i also feel could be the last as this car is driving me crackers ,maybe time to cut my losses and ged rid......Anyway temp gauge on 3 bars ,fan cutting in OK but engine light on,took to garage this morning ,scanned with obd11 and a scanner no luck in clearing the light,i went to work and called back later were they said it was now clear,upon asking what they did i was told unplug and replug the big fuses and the ecu side,aparentley that took it out of limp mode and light went out,however i now have the same problem before i fitted new (blue) sensor temp hitting red before fan kicking in ,OK  fan is working but not at the correct temp as it did when i replaced with new one.Realy not sure what to do now,money spent but no solution and theri is only a certain amount you can spend before throwing in the towel.

[paul.h]

Maybe move the blue sensor wire a bit to see if it was catching on something and the insulation has worn through. All this sensor does is earth the wire at the high temp so it could give the same effect if the wire was earthed. It is possible the garage disturbed the wire when unplugging the ecu.

 

Pity the garage could not read and clear the code normally since this may have given a clue on why the engine light came on.

[den9112]

T be honest i have no confidence in touching anything electrical in case the engine light comes on again ,because the garage told me if it happens again its a Auto electricians job,i will move it around but i wont hold my breath,

[paul.h]

If you have another look at the Diagnostic Help post, there is a member JoshC5-138 in the West Yorkshire/Lancashire area, who possibly could be near to you.