wammers said:
It is related to auxilary fans, if the engine temp gets to high the aircon fans will come on at slow speed to assist the viscous fan. If it is giving a false reading that could be your problem.
Click to expand...
Hat up 4u my man,i don't mean 2 argue,but according 2 rave the sensor with the brown plug (engine cooling temp sensor)is the 1 which tell the ecu tht engine is hot,and orders the aux fans.the 1 ur telling me about (coolant sensor) is only 4 the dash temp guage,it has a light blue or green single wire
Right?
 
The HEVAC panel provides a signal normally at 12
volts for “off” condition and 0 volts for the “on”
condition, which in the case of petrol vehicles is fed
into the ECM and diesel vehicles directly onto the
coil of relay 18. In line is the Air–Conditioning
pressure switch 2, which turns the fans on/off.
When relay 18 is energised, it provides connection
between relays 13 and 14 (fan 1 and 2) in series or
parallel with each other. This is dependent upon the
state of the air–conditioning pressure switch 1.
For the petrol option, when the signal enters the
ECM, the ECM will switch the output on/off to the
fusebox. The ECM will switch the output on
sometimes for engine cooling reasons even though
the engine has been turned off.

The single wire sensor is for the gauge only, nothing else. Operation of the gauge can be checked by diagnostics which will "Force" the gauge to go to either Cold, Normal or Hot positions.
I suspect a faulty ecu coolant temperature sensor or pressure switch. Either are relatively cheap to replace, the sensor is a lot cheaper than the pressure switches at around £10 and the switches will cost around £40 for the two.
I appreciat that the ambient temperature is a lot higher in your part of the world than in the U.K. and most of the time over here, the condenser fans do not run at all.
Is your Condenser (Radiator) clean regarding the fins ? as any obstruction will seriously affect the airflow not only through it but also the engine coolant radiator.
If the engine itself is definately not overheating then the problem is not as serious as you think. The fans are keeping the aircon refrigerant pressure down, if it increases beyond a safe limit, the pressure switch will disable the aircon compressor clutch to prevent damage to the system through over pressure.
I would replace the sensor first, if that does not work then check the operation of the pressure switches (Located close to the aircon dryer below the front bumper) with a multimeter.
If you need part numbers for the sensor or the switches, let us know.
:behindsofa:
 
Irishrover said:
The HEVAC panel provides a signal normally at 12
volts for “off” condition and 0 volts for the “on”
condition, which in the case of petrol vehicles is fed
into the ECM and diesel vehicles directly onto the
coil of relay 18. In line is the Air–Conditioning
pressure switch 2, which turns the fans on/off.
When relay 18 is energised, it provides connection
between relays 13 and 14 (fan 1 and 2) in series or
parallel with each other. This is dependent upon the
state of the air–conditioning pressure switch 1.
For the petrol option, when the signal enters the
ECM, the ECM will switch the output on/off to the
fusebox. The ECM will switch the output on
sometimes for engine cooling reasons even though
the engine has been turned off.

The single wire sensor is for the gauge only, nothing else. Operation of the gauge can be checked by diagnostics which will "Force" the gauge to go to either Cold, Normal or Hot positions.
I suspect a faulty ecu coolant temperature sensor or pressure switch. Either are relatively cheap to replace, the sensor is a lot cheaper than the pressure switches at around £10 and the switches will cost around £40 for the two.
I appreciat that the ambient temperature is a lot higher in your part of the world than in the U.K. and most of the time over here, the condenser fans do not run at all.
Is your Condenser (Radiator) clean regarding the fins ? as any obstruction will seriously affect the airflow not only through it but also the engine coolant radiator.
If the engine itself is definately not overheating then the problem is not as serious as you think. The fans are keeping the aircon refrigerant pressure down, if it increases beyond a safe limit, the pressure switch will disable the aircon compressor clutch to prevent damage to the system through over pressure.
I would replace the sensor first, if that does not work then check the operation of the pressure switches (Located close to the aircon dryer below the front bumper) with a multimeter.
If you need part numbers for the sensor or the switches, let us know.
:behindsofa:
Click to expand...
thanks irish
so even if there is no faults stored in the engine ecu the ect sensor can be faulty?
and what about the temp gauge?when i load electrilcal stuff on the car it will creep up more,the ect can cause the guage to play like that?
 
The fuel and temperature gauges are electrical and rely on a reference voltage which is provided by a voltage stabiliser. Obviously the slight voltage drop when other equipment is switched on is upsetting the electronics within the gauge and changing the reading. Normally if the voltage stabiliser is faulty I would expect both the fuel and temp. gauges to show false readings. I think the stabiliser is an integral part of the Instrument Cluster electronics and therefore non repairable. Word of caution...if you are thinking of replacing the instrument cluster, be sure to get one with a lower mileage than your own otherwise you will be stuck with a higher mileage recorded than the car has done. If the mileage is lower on a replacement, it will update to the actual mileage of your car.
 
irish now my head hurts.fuel gauge isn't acting up unless on a descent or a hill.the thing that confuses me is that when the temp gauge is one mark above middle with the aircon on,the series running condenser fans(as soon as i switch the ac on they run in series) switch to parallel,the temp gauge will move to the 1 oclock position and remain there unless i switch off the ac,the temp gauge will drop to middle and fans will cut off.and if the temp gauge is at 1 oclock and i turn the engine off and put key to pos 2,the temp gauge is in the middle.only on idle i am having this pro,as long as the car is running no pro,when i hit the traffic it will creep.
lets say that the engine is overheating,the temp gauge isn't moving to the red area,coolant isn't boiling nor getting less.is it safe for this engine to run at a temp gauge with the 1 oclock pos?
 
irish and what about engine grounds?people are suggesting to clean them and replace cables,but mines seem at a good condition,and i tried to remove one ground,it was so tight that i broke my hands trying to untighten the nut,and it didn't move
 
irishrover said:
irish now my head hurts.fuel gauge isn't acting up unless on a descent or a hill.the thing that confuses me is that when the temp gauge is one mark above middle with the aircon on,the series running condenser fans(as soon as i switch the ac on they run in series) switch to parallel,the temp gauge will move to the 1 oclock position and remain there unless i switch off the ac,the temp gauge will drop to middle and fans will cut off.and if the temp gauge is at 1 oclock and i turn the engine off and put key to pos 2,the temp gauge is in the middle.only on idle i am having this pro,as long as the car is running no pro,when i hit the traffic it will creep.
lets say that the engine is overheating,the temp gauge isn't moving to the red area,coolant isn't boiling nor getting less.is it safe for this engine to run at a temp gauge with the 1 oclock pos?
Click to expand...
irish now my head hurts.fuel gauge isn't acting up unless on a descent or a hill.the thing that confuses me is that when the temp gauge is one mark above middle with the aircon on,the series running condenser fans(as soon as i switch the ac on they run in series) switch to parallel,the temp gauge will move to the 1 oclock position and remain there unless i switch off the ac,the temp gauge will drop to middle and fans will cut off.and if the temp gauge is at 1 oclock and i turn the engine off and put key to pos 2,the temp gauge is in the middle.only on idle i am having this pro,as long as the car is running no pro,when i hit the traffic it will creep.
lets say that the engine is overheating,the temp gauge isn't moving to the red area,coolant isn't boiling nor getting less.is it safe for this engine to run at a temp gauge with the 1 oclock pos?[/
 
jorjio_k said:
irish and what about engine grounds?people are suggesting to clean them and replace cables,but mines seem at a good condition,and i tried to remove one ground,it was so tight that i broke my hands trying to untighten the nut,and it didn't move
Click to expand...
:violent::rolly::Cry:
 
As long as the needle is in the white area, out of the blue and red, to compare with the fuel gauge, say anywhere between a quarter and three quarters it should be ok. If you want to be really sure you could get the engine temperature read with either an infra red or other temperature reader to confirm the precise temperature.
The operation of the fans is good, as is the fact that it seems from what you have said, that the engine is not actually overheating or using any coolant, the problem is just irritating rather than something serious.
 
Regarding the engine ground connections, as a temporary check as to their condition, get a length of heavy wire and secure it to a bolt/nut on the engine and put the other end to the negative connection on the battery..maybe even a jump start cable ??
 
Irishrover said:
Regarding the engine ground connections, as a temporary check as to their condition, get a length of heavy wire and secure it to a bolt/nut on the engine and put the other end to the negative connection on the battery..maybe even a jump start cable ??
Click to expand...
by doing that then i check the gauge to see if it is droping back to the middle?
 
As I said, the sensor or the gauge could be the problem, the sensor is the cheapest and easiest to troubleshoot by substitution.
The pressure switches seem to be working as the fans are cutting in and out as they should. The gauge reading should drop shortly after the fans cut in because of the increased air flow through the coolant (Engine) radiator, this indicates an electrical problem with the gauge itself or within the circuit.
 
Irishrover said:
As I said, the sensor or the gauge could be the problem, the sensor is the cheapest and easiest to troubleshoot by substitution.
The pressure switches seem to be working as the fans are cutting in and out as they should. The gauge reading should drop shortly after the fans cut in because of the increased air flow through the coolant (Engine) radiator, this indicates an electrical problem with the gauge itself or within the circuit.
Click to expand...
irish thank you very much for your assistance,i will replace the coolant sensor (sender for the gauge) and i will check the grounds.you have been a great help.
 
thank you everyone for your posts and your help,i hope i will solve my problem soon and i will keep u updated of what was the problem.;)
regards from lebanon
 
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