I have a 2002 volvo s60 2.4 turbo i just purchased and the temp guage doesnt work, the fan wont run and the car has issues starting. I believe the cooling sensor was just replaced. When the cooling sensor is plugged in it will not start and when it is unplugged the car will start but it turns over for a bit before it will fire up. I believe the injectors are kicking too much gas out. I heard that the module may be bad and need to be replaced or reprogrammed. Not sure if the cooling sensor is linked with a module or not or what my next step should be to get the fan to cool the engine and the car to start up when the sensor wire is connected. Thanks
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Re: Volvo Cooling sensor / fan arent working
Take it one step at a time. First, replace the coolant sensor and try to get the car to start WITH the sensor connected. Make sure that you DO NOT use any teflon tape when installing the switch (this will isolate the switch which will not ground it, making it not work). Th computer receives signals from numerous sensors, and makes adjustments according to inputs received. When the computer gets a signal that the car is still cold, it will adjust the fuel/air ratio to make it run richer (more fuel than air). Once the car is running it will run rough due to a improper mixture since the computer is never sensing the car is warmed up since the sensor is unplugged. This will also account for the slow start due to a richer fuel mixture.
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the fan will come on when the coolant temp reaches a preset temperature normally around 85 C
by passing the cooling temp sensor to have the fan running all of the time is a pointless exercise as if the thermostat is not open there is no coolant to cool and if the thermostat is fully open then the fans will be running anyway
what you should be thinking about is finding out why the vehicle is overheating when under load
have the fault codes read first
possible reasons are
at converter blocked
radiator cores blocked
transmission over heating and putting he radiator under stress coolant temp sensor faulty or relay faulty or fuses blown
If the car has air conditioning ... try turning that on to increase the load on the cooling system at idle ..... and see if the fan kicks in. If not ...something is wrong.
But since the radiator was replaced ... I would recheck all connections going to the fan ... you never know when something could be loose.
If you are handy ... put power to the fan and see if the fan is broken (probably not)
Since your temp gauge is working that means your coolant sensor is working ... which is good. If the sensor goes bad that can affect what the car computer tells the fan to do (but most cars default to fan on if the sensor goes belly up).
So that leaves the fan relay .... usually under the hood somewhere ... but I am not familiar with this Volvo. After you locate it ... and if you are lucky ... there will be an identical relay for another system (hopefully not essential to keep the car engine going) ... switch them and see if the fan goes on
Good luck troubleshooting
first you need to check your cooling fan working you can do so by turning your a/c on if your a/c is working properly/if so turn off a/c and let car sit till overheat and see if fan kicks in.if not possible your fan circuit electrical or sensor related/and also check for air in your system bleed system good check for circulation open radiator cap.
the boost preasure sensor is located on rear of the cooling fan housing at rear of engine near air box, theres a turbo control valve and its located on the top of the engine in the back near air box, you can say its behind the driverside head light in engine compartment. hope this helps.
Volvo Radiator, Thermostat and Sensors
system's temperature controls include all coolant temperature sensors,
Volvo thermostat, Volvo radiator or expansion tank cap, cooling fan(s)
and fan clutch (if equipped). These cooling system parts function
primarily independent of the engine but control the engine either
through cooling or by sending control signals to your Volvo's
The Volvo thermostat is a spring-loaded
valve that opens and closes based on the temperature of the coolant
flowing through it. A high temperature reading followed by a drop to
normal temperature (or a continuously low temperature) is a common
first sign of a sticking Volvo thermostat. However, many other
conditions may cause these symptoms, so you need to know how to
eliminate each possibility.
The Volvo radiator or expansion
tank cap is also a spring-loaded valve reacting to system pressure. It
serves to maintain proper system coolant level at predetermined
pressures. It must always be replaced with an exact replacement cap
with the same pressure setting. Never use other caps except for
A belt-driven fan blade for pulling
air through the Volvo radiator is usually on the Volvo water pump
pulley and should have a fan clutch to control it. The fan clutch
allows the fan to turn with the belt at low engine speed and
"free-wheel" at higher speeds. A bad fan clutch either doesn't allow
the fan to spin at low speed (overheating in traffic) or doesn't allow
it to free-wheel at high speed (potential overheating on highway or
reduced gas mileage).
An electric fan can be either by
itself (usually front-wheel drive) or auxiliary (used with a mechanical
fan). Both types are controlled via a temperature sensor - in the Volvo
radiator or upper Volvo radiator hose or on the Volvo thermostat or
Volvo water pump housing. This sensor is usually an on/off type switch
with a fixed temperature setting. (Some vehicles may have 2-3 settings
for multi-speed fans.) This sensor is commonly called an "auxilliary
Other common temperature sensors are: 1) gauge
sender (variable output); 2) warning light sender (on/off type); 3)
lambda and/or fuel injection sensor(s) (variable to control fuel
injection settings); 4) thermo-time switch (cold start valve control).
Your Volvo may have other sensors as well.
control is critical to both performance and emission control.
Unfortunately, this system is the most difficult to troubleshoot
without proper equipment and diagrams. It's even more difficult with
computers that adjust timing, idle speed, vacuum and fuel delivery
automatically to make up for potentially faulty temperature sensor
Maintenance of your cooling system sensors is
virtually impossible since there's nothing really to "maintain".
Keeping them clean both internally (coolant replacement) and externally
(engine cleaning) is the best way to ensure trouble-free driving.
Checking and replacing all parts at the factory-recommended time or
mileage limits helps as well
i am a masrer volvo ASE MASTER TECH yes the one with thermometer is the coolant low and square sounds light the Generator light and why is coolant low???? is fan working properly and relay?? and under thermostat there is a coolant temp sensor and to clarify meaning wet is that the coolant temp sensor has enough coolant to the sensor INSIDE THE THERMOSTAT housing