1-pin water temperature sensor

[John Young]

I thought I was getting close to having solved my 52 and 55 CEL and in fact I had gotten rid of the 55 after trying varous anti-knock sensor replacements and now this...

The ONLY error code I'm getting is a 22. Which relates to the water temperature sensor and now the truck barely starts and then stalls if I press the accelerator. Previously it had run well even with the 52/55 CEL error. It's also worth mentioning that I had noticed when I got into this that the water temperature sensor actually was disconnected.

So ok... Let's replace the water temperature sensor and see what happens. I looked up the part number for my 93 fuel injected 80 and this came up: 89422-35010; which looks like this according to Google:

But here's the thing: my truck has a single pin temperature sensor. Here's a photo:

The wiring harness on the truck also seems only to have a single wire--plug itself is missing, but I don't see evidence of a second wire that would go to it.

I'm hoping that the collective wisdom of Mud can help me solve this. ToyoDIY says my truck should have a two wire sensor; I only have one. If I want to replace the sensor, which I think is probably a good idea while I am replacing the plug, what Toyota part should I get?

Or what other silly thing am I missing? I'm trying to get the truck ready to go with my son away to school by the end of next week so the pressure is on a bit.

 

[John Young]

I did more general searching and did find this in New Zealand:

Toyota Water Temp Gauge Sender (M16 Thread) - Common 1JZ / 2JZ / 3S-GE etc. - NZEFI

Genuine Toyota 1-pin Water Temperature Gauge Sender as found on many Toyota engines manufactured during the 1990's/early 2000's This is the engine coolant temperature sender that is connected to the water temp gauge on the dashboard (instrument cluster). Note that it is NOT the 2-pin sensor...

www.nzefi.com

And then I began to question assumptions....

More detective work and I learned that our 1FZ-E engines have a coolant temperature SENDER (part number 8342016040) and also a coolant temperature SENSOR (part number 89422-35010). The former relates only to the temp gauge on the dash and the latter is used by the ECU.

I think what I did in all my fooling with the anti-knock sensors is that I damaged the wiring going to the coolant sensor which is up and to the right of the 1-pin sender.

I'm a little embarrassed by all this but I am going to leave this post up in the hopes that some might benefit from my mistake in future.

EDIT: Sure enough; I went and looked and one wire had pulled out of the sensor plug.