First I want to give a sincere thank you to the folks who spend their time and effort keeping this site together. It's been a great resource and again, THANK YOU.

Now for my next fix it. I have a 1993 Toyota 4x4 SR5 (Japanese import, if that matters) that I've pretty well taken care of all the stay on the road issues. (Fingers crossed) Now I'm going after a couple "little" issues that need attention. My speedometer is showing approximately twice the speed I'm actually traveling. I've run across information that it's probably the speed sensor on the transmission? If anyone has info on this I'd love to read up on it. Pictures, part numbers, best manufacturer etc........... I've looked the part up and the info I get is all over the place.
I also have a code 22 showing up. The check engine light is very intermittent and sometimes doesn't come on at all. Code 22 is the coolant temperature sensor located at the rear of the engine. My temp gauge inside the cab looks like it's working fine and I haven't had any over heating issues but I don't know enough about what that sensor does to accurately diagnose the 22 code. Same questions as above. Info, part number, best resource for the sensor.........etc...........All info is absorbed and greatly appreciated. Cheers.............

 

The coolant temp sensor is different than the coolant sending unit that controls your gauge. If the part number starts with 83420-XXXXX than that's the sender for the dash gauge. You don't want that.

The coolant temp sensor gives info to the ECU so it can better adjust the injector duration. There's probably not much to testing the sending unit other than an ohms test at a certain temp range. That info i do not have. You might try cleaning the connections at both the sender and the connector, and inspect the wire for any breaks.

If you decide to replace, 89428- should be the first five of the coolant temp sensor. I think the one for your model is 89428-89101, but research first. Fwiw, that part nuimber is $52.00 on Amayama/EPC-data.com. They don't charge tax, but watch the shipping cost. For a part that small and light it shouldn't be bad. They are legit(not selling counterfeit). I've gotten a lot from them over the years.
As far as the speedo, idk. Never had to work one that system. But i'm sure others can help who have.

 

Thanks for the info. I found a coolant temperature sensor part # 89422-3510 which shows it fits my truck. This sensor (according to my shop manual ) is located at the rear of my engine under the hood. My dilemma is everything I've read about symptoms isn't happening. My gauge inside shows middle. My fan runs. My truck isn't running hot. As far as gas mileage and engine efficiency I see no signs of those either. Could this code 22 be generated by something else I'm not aware of? Could it be a rouge code? The check engine light hasn't come on for a few days now. The truck idles fine. I pulled the EFI fuse to clear the code but it's still there. Thoughts? Thanks for all the info............

 

You’re correct, 89422-35010 is the right part number. $33 on amayama with shipping.

The FSM would give you all the things that could set the code. Keep in mind, what that sensor does won’t reflect on the dash gauge. Your vehicle can be running at perfect operating temp, gauge right where it should be, but if that coolant temp sensor falls out of the parameter programmed in the ECU it’ll set a code.

So you clear the code, but as soon as you turn the engine on it restablishes?

 

I'll post that answer in a couple weeks. I just ordered the part yesterday so after I get it installed I'll clear the codes and see what happens. If that sensor is bad why am I not seeing or feeling any symptoms of that sensor going bad? So far the code 22 is the only thing that even brought it to my attention. Thanks again for taking the time to walk me through this. Cheers...............

 

If the ECU gets bad data, or no data, from a sensor, it has default settings it can fall back on. The engineers designed it to favor a rich condition, as that’s much safer for the driver than a lean condition. Then it sets a code to alert the driver that something’s not right. This default towards rich is one reason why excessive fuel consumption is often mentioned as a possible symptom with many codes.
Sometimes the issue is one that the ECU can’t compensate for, say a bad injector, and you feel the misfire while driving. But something like an oxygen sensor going bad is one the ECU can easily work around. But these "fall back" default settings by the ECU don't tend to favor emissions, which is why areas with required smog tests will usually fail a vehicle if there's a code stored in the system, even if it passed the tailpipe test.