89whitetoyota

I have a code 22 showing up on my 22re (engine coolant temp sensor). I know what this is and where it is located, but what I don’t know is what ramifications this will have on the motor should it be bad. I will give you some symptoms of what I have going on, also threw a 41 to and that is TPS circuit fault, so some of these can/will be related to that also. Keep in mind I just bought a new engine coolant temp sensor about 5 months ago from Auto Chevy (Autozone). Original motor with 202k on it.

1. I don’t have a high warm up idle in hot or cold weather.
2. The motor has insane hesitation but will get up to 80mph but any hill or incline and I will lose 20mph in a few minutes
3. I have to crank the motor for 30 seconds every morning to get to barely idle, then after 15 minutes it will be ok.
4. I just had the top of my radiator blow off, so I now have a new radiator and still am loosing coolant somewhere.

I haven’t check the oil to see if its milky yet, but any input on what the coolant temp sensor will do to the motor should it go bad would be heloful.

thook

I'd guess you're not actually having a problem with the sensor, but rather with your wiring and losing signal to the ECU. Of course, you can possibly get a bad part from the beginning, but you'll need to test the sensor to rule it out.

In either case, if the sensor's bad or the wiring's bad, the ECU needs to know what the engine temp is to regulate timing and injector duration. For example, when starting and/or the engine's cold, the injectors need to stay open longer for fuel enrichment and advance timing to better complete combustion and bring the engine up to temp quickly. Once the engine is actually warm, fuel enrichment is reduced (based on engine load) and timing is adjusted less or more.....again, based on engine load. Needless to say, you will have a lot of problems with idling, power, fuel economy, and could possibly overheat.........possibly blowing the headgasket. As well, even if it never overheated, were you to continue to drive it, you will eventually have a lot of carbon trash in the cylinders, on the valves, foul the O2, and possibly clog the CAT.

So, test the part to rule it out, and then procede to test at the ECU connector for the wiring.

89whitetoyota

A help as always. Thook, do you have way to test this specific sensor, I looked through the Haynes but no luck. It did have all of the test for the TPS, just nothing about this one.

thook

I like to test the sensor in a pot of water so I can watch what the meter does. You can test it while on the motor, but in a pot is basically how the manual illustrates testing. You can pull the sensor and plug the hole real quick with a cork to keep from losing much coolant.


1) With the sensor removed from the engine, stick a short piece of vacuum tube or equivalent (I use aquarium pump tubing) on either terminal.
2) Stick either probe in each of the tubes making sure you're getting could contact on the terminals.
3) Draw up a pot of cold water and measure the temp with a therometer.
4) Place the sensor in the water with probes attached and record the resistance. Compare it to specs in the following link
5) Heat the pot on the stove with the sensor still in it and note the meter behavior. Resistance should steadily fall as the temp rises. If there's any dropouts in resistance on the meter or the sensor doesn't respond to temp change, then it's bad.
6) If it passes those tests, let the water come to boil and take note of temp and resistance. Again, compare to the following link.

http://www.autoshop101.com/forms/h32.pdf

farmboy2130

Unfortunately i broke my temp sensor today attempting to remove it for testing. Guess it needed replace it anyway. Thanks for the link thook. Gonna test my new one before installing.

BamaYota1

http://personal.utulsa.edu/~nathan-b...40engineco.pdf

Ect test procedure in FSM. Obviously thook is dead on correct.