hey i never noticed this before but if i turn the key on my car the fans turn on and i was wondering if that was normal. i dont have the car on and it was not hot. any opinion?

 

The fans don't normally run unless it is either hot or you have the A/C on.

 

well i blew my throttle body and am gettin it fixed but all of a sudden i noticed the cars fan kept turning on and the engine is not even running. is it possible that its just an electrical glitch due to the faulty throttle body?or am i looking in to something worse?

 

+1^ - only if the A/C is on, or the car is very hot. That includes defrost settings because that also turns on the A/C.

If your A/C is not on, you might have some sort of temp sensor issue or similar. You don't want the fans running all the time in general, and if the temp sensor is overstating how warm the engine is, that can cause at least cold start issues, too.

Test by pulling the fuse for the A/C if you really want to check that route.

 

its a sensor issue. I had a mazda 6 and that happened. Believe it or not, the fan ran even after I turned off the car, took the key out of the ignition and walked away from the car.
need a sensor re-flash, what ever the sensor is, i'm not sure.
if under warranty, take it to a dealer and they'll do it.
Best of Luck

 

Are you the first owner? Maybe previous owner "fixed" them (i.e. "direct" jui-
ce at start-up, not depending on engine temperature). Finally, a short circuit
is the only other thing I can think of. I doubt the sensors are involved, since
they react to engine temps', & you say they turn on at start-up. Maybe it's time for a visit to the auto electrical shop; hope not.

 

YES i've noticed that when i drive the car stop shutoff and run into a store quickly upon returning return when i put the key in and turn to the first position i've noticed the fan kick on before i actually start.. Just happened yesterday!

 

I'm really starting to hate our car's electrical systems. I lost all braking function (ABS, EBD, Booster, all of it) due to a small broken wire to the rear high mount stop light on the wing. Buried in an inch thick wad of cable, which runs from the dash down the passenger side to the rear - I could not have traced that wire no matter the time, because I'd need to check continuity on every brake-related wire in the bundle (a lot). CONSULT checks them all at once, so I paid $200 for a single broken wire.

I agree with j.arnaldo that the most likely problem is a "short", i.e. a closed circuit allowing power to get to the fans regardless of the upstream sensors. Sensors are very involved in fan control, but from the sounds of it, not very relevant because the A/C is off, and/or the engine is off and cold. Shorts are possible as is deliberate "hot-wire" but usually people do that to directly control the fans with a switch, or they are on all the time. Normally fans do not ever turn on until things are pretty darn hot unless A/C is on (as in near 90-100 deg C).

Cooling fans are controlled directly by the ECM depending on the following inputs:

• Crankshaft position sensor (POS)
• Camshaft position sensor (PHASE)
• Battery (Voltage)
• Wheel Sensor (Vehicle Speed)
• Engine coolant temperature sensor
• Air conditioner switch (A/C ON status)

At rest, only the ECT sensor is considered assuming the rest of those sensors are correct, unless the A/C is on, or the A/C switch is telling the ECM that it is on. The rest are only relevant if A/C is on and the vehicle is pretty warm, and/or moving. Even then, after 50 mph at 203 deg F the fans turn off regardless of the A/C.

The control system has 3-step control [HIGH/LOW/OFF]. The FSM says regardless of vehicle speed, if the Coolant Temperature Sensor says >=203 deg F, kicks the fans to low speed. If above 212 deg F, kicks the fan speed to High. Below 203, they should not turn on unless the A/C is on. If the car is not moving, the engine is cool (or below 203 deg F!) the only significant input the ECM uses when A/C is off is the Engine coolant temperature sensor.

If your A/C is off, you don't have shorts anywhere, and the fans turn on, then it's highly likely the ECT sensor is sending bogus data to the ECM. 203 deg is really warm. The last wildcard is the signal out from the ECM goes through the "IPDM E/R" which has 3 fan relays, each corresponding to fan speed control(s). If you did have a short between the battery and the IPDM then the fans should not work if I read the diagram correctly. Every speed has a relay.

You really need the FSM to perform the Cooling Fan electrical checks if you want to diagnose this yourself. Running the ECM through CONSULT II is just going to tell you if the ECT signal is off, or the A/C switch is telling the ECM that it's on when it's not, very unlikely due to the many other negative results so I doubt that is the direct issue. Don't waste your money hooking up to CONSULT checking sensors until you've checked wiring.

Honestly, I think you'll find a wire is open somewhere, shorting out and providing continuity when there shouldn't be a closed circuit. I agree with j.arnaldo that the most likely problem is a "short", i.e. a closed circuit allowing power to get to the fans regardless of the upstream sensors. Check the wiring from the fan harness back toward the engine first for continuity with a MM. ONLY once the harness enters the "IPDM E/R" and it all checks good w/o shorts, then it's time to take it to a shop. Your chance of diagnosing problems in there or upstream between the "IPDM E/R" and the ECM are near zero w/o some expertise and equipment. That's where CONSULT II or equivalent gets really helpful, you need to know the signals that the ECM is getting.

Sorry for the essay. HTH, just trying to point out how in general the process works, and hopefully eliminate wild goose chases and/or an expensive trip to the dealer, unless you're still under bumper to bumper warranty, then it should definitely be covered because something is "broken" that is not a wear item.

Good luck, interested to hear what you find.

 

well im thinking its a short due to the fact that my no.1 coil blew 3 times already and that the fan is stuck on. do you think i should just try a whole new harness for it? will a convertible harness from the same year work? and my fuel pump went out also so im screwd and i dont have bumper to bumper because when my car broke down i had to take it in and the dumb *** towed it to the dealership instead of ma pad and they noticed that a stillen supercharger doesnt come equipped with the stock zs lol. damn ever since that damn supercharger ive had loads of problems...

 

SC? Then def check for changes to the wiring. Previous owner probably did hard wire the fans on to try to avoid heat soak on the SC. Coil is almost certainly not related, that's another issue.