Code 22...Which Sensor

[DeMoN2318]

I have an intermittent code 22...the CEL will come on, then go off, then come on, etc in non-uniform intervals

I looked in the TSRM and the drawing is hard to interpret which sensor is the "Water Temp Sensor"
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=FI&P=113

So I started to search and I found this picture, in this thread
http://jdub.supramania.com/Mechanical/Thermo Housing.jpg
http://www.supramania.com/forums/sh...-7MGTE-Intro&p=1398141&viewfull=1#post1398141

It appears the OP rewired the "Radiator Cooling Fan Sensor Switch" and their Code 22 went away...but I would expect the "ECU Coolant Sensor" to be the "Water Temp Sensor"


So...does anyone know which sensor is the cause of the Code 22?


Any and all input is appreciated!

 

[jetjock]

The EFI sensor is the one upstream (engine side) of the thermostat. The 2-wire one (EFI sensors are almost always 2-wire). The code is set when the input (THW) is open or short circuited: more than 4.8 vdc or less than 100 mv.

 

[DeMoN2318]

Thanks JJ!!!

 

[DeMoN2318]

I wired in a new connector since mine was broken and loose...
didnt fix the code 22


So I checked the resistance accross the sensor and it checked out...

I then checked the voltage accross the sensor and it was 0...both in vdc and mvdc...

So did the sensor short internally?

WTF!!!!

 

[f00g00]

Since your wiring has been modified you will need to read end to end from the ecu to all sensors.

 

[DeMoN2318]

Replaced the sensor, didnt fix the code 22.

pulled the ECU and check continuity to sensor plug and it was good.


put everything back together (without changing anything), and no code 22...


God I love electrical stuff

 

[jetjock]

Next time measure voltage. That way you can check the wiring integrity without removing the ECU. Use of ohms/continuity should, in most cases, be left as a secondary check.

 

[DeMoN2318]

Next time measure voltage. That way you can check the wiring integrity without removing the ECU. Use of ohms/continuity should, in most cases, be left as a secondary check.

I dont understand how to check voltage with the ECU connected...

Do I just shove the prob into the back of the connector?


I am a mechanical guy...EEs melt my face

 

[jetjock]

It's called back-probing and yes, that's what you do. I was thinking more at the sensor though since the voltage supplied by the ECU can be used to verify the wiring is good.

Understand about the face. I once smiled and mine was sore for a week...