How can we bypass the cooling sensor by the thermostat?

Though it could be either in feeding of data or gauge itself but most likely the gauge would be faulty. I assume it to be mechanical gauge

Depending on how fast it reaches boiling temp, it could be a leaking head gasket or a blockage in the system. I am also assuming the cooling fan comes on at the correct temp.
A blockage would do the same thing as a stuck thermostat, and a leaking head gasket would cause the system to have extra pressure.

You can't. The output of the sensor is used by the PCM to control fuel mix and radiator fans. Without it, the car probably won't run, and if it does, it will run poorly since there is no temp input to the PMC for fuel mixture computation.

if the sensor is for the car and the correct temp more than likely the car is not hot enough to turn on the switch , hence fan.

the fan works, if you bypass switch..

Thermostat? engine cooling?
2 engines, here, LYA adn LY7.
nobody here posts engine, why do that?
so ill post only for 1.
the LA1
here are the steps.
NO FSM Sux huh? nor an alldata.com account, why not that? 15 bucks?


STAT out.
Remove the air cleaner and duct assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls - 3.4L.

Drain the coolant until the coolant level is below the thermostat. Refer to Cooling System Draining and Filling (Refer To List 1) .

Remove the crossover exhaust pipe. Refer to Exhaust Crossover Pipe Replacement (Refer To List 2) in Engine Exhaust.

Remove the radiator hose from the thermostat housing.

Remove the thermostat housing bolts and clean any sealer from the bolt threads.

Remove the thermostat housing and gasket.
remove STAT
next is crossover page.

Disconnect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection (Refer To List 1) in Engine Electrical.

Remove the throttle body air inlet duct.

Drain the coolant from the cooling system. Refer to Cooling System Draining and Filling (Refer To List 2) in Engine Cooling.

Remove the inlet radiator hose from the engine. Refer to Radiator Inlet Hose Replacement (Refer To List 3) in Engine Cooling.

Remove the thermostat bypass pipe. Refer to Thermostat Bypass Pipes Replacement in Engine Cooling.



Remove the exhaust crossover heat shield bolts.

Remove the exhaust crossover heat shield.

1. Remove the exhaust crossover pipe studs/nuts.
2. Remove the exhaust crossover pipe.

end , remove.

now the bypass pipe FWD cars SUCK

1. Disconnect the left engine mount strut from the engine.
2. Remove the heater hose from the bypass pipe.
3. Remove the thermostat bypass pipe to throttle body nut.
4. Use the J 38185 in order to remove the thermostat bypass pipe hose clamps (1,5).
5. Remove the thermostat bypass pipe to cylinder head nut (3).
6. Remove the thermostat bypass pipe bolt (4).
7. Remove the thermostat bypass pipe hose.
8. Remove the thermostat bypass pipe.

sigh.....
why not log in to alldata.com
read the page then ask ques tons that are not clear.
and next time post the engine type.
above is just 1 engine.

See if that gem as a sending unit should be right next to the thermostat standing up like a sore thumb change it and see what happens have a good day thanks

First check the fuse then the temperature sensor in the radiator by bypassing it.

If you want to bypass the heater core, easiest was is to remove both hoses from the heater core, get a hose connector and 2 hose clamps.

Other than that, you could buy a few feet of some heater hose at your local auto parts store, and go from the water pump to the thermostat housing (although this would bypass your temerature sensors, would probablly cause a check engine light, and may prevent your cooling fan from working properly).

I don't see any parts store anywhere offering a "single" bypass hose, nor have I heard of one for this vehicle. If you do need to bypass it, your solution is above.

I hope this information helps you, and I do wish you luck on your repair.

CARS THAT USE ELECTRIC FANS HAVE A THERMOSTATIC SENSOR THAT TELLS THE FAN OR FANS WHEN TO COME ON BASED ON THE COOLANT TEMPERATURE. THIS SENSOR HAS GONE BAD. WHEN THE AC IS TURNED ON IT BYPASSES THIS SWITCH AND RUNS TO KEEP THE CAR COOL, BUT BY THE TIME YOU TURN THE AC ON THE CAR HAS BECOME TOO HOT ALREADY. YOU NEED TO REPLACE THE THERMOSTATIC SENSOR. THEY CAN BE A LITTLE PRICEY, BUT NOT A WALLET BUSTER.