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truckman
29-04-2009, 01:22 PM
Have Supra 644 unit that will shut down intermittent and read "Engine Hot" When it is
running display will show "WT" 153f, so it would
seem to be running very cool. The unknown that
I don't have the answer is on the display what
is "CDT" which is being also displayed as a temperature reading and I am getting 211 f. Any suggestions greatly appreciated

abbsnowman
29-04-2009, 04:08 PM
CDT= Compressor discharge tempature.
Sounds like you may have issues in the condenser / radiator.
She's running hot. Sometimes the water temp sensor fails but if your getting CDT alarm as well, hmmm....

truckman
29-04-2009, 07:03 PM
I don't know. It says WT is 153 f and the alarm is
shutting down saying "Engine Hot". The CDT temp is 211 f, where should that be or is 211 f OK?? It could just be the temp sensor, but I am not sure what the 211 f on CDT represents and if that is OK.

djbe
29-04-2009, 08:17 PM
CDT is the temperature of the refrigerant on the compressor discharge side. You should find the sensor somewhere on the compressor cylinder head.

The strange thing is that both the WT and CDT temperatures that you have got seem to be within acceptable parameters according to all of the manuals that I have.

It is possible to check the sensors out using an ohm meter. The reading you should get depends on the temperature of the sensor at the time.

Does the engine feel as if it is overheating?

I might be wrong but you could find that your problem lies elsewhere, don't ask me why but I have had Supras before giving false error messages when the problem has been worn alternator brushes or a bad micro +ve supply from the battery. It may be worth looking at those.

good luck.
djbe

abbsnowman
01-05-2009, 03:37 AM
How long does unit run before it codes?
There is a plug (called the high current plug) on the micro box. It is the entry for the wires to the box. If there is moisture in there, these units do silly things.
I still can't believe though that you would get 2 codes that are somewhat related if there were not an issue.
Do you have a laser gun?
Oh and your sensor readings are within the normal range as DJ said.

djbe
04-05-2009, 06:02 PM
There is a plug (called the high current plug) on the micro box. It is the entry for the wires to the box. If there is moisture in there, these units do silly things.


Valid point and something I had forgotten about as haven't seen it for ages. As abbsnowman says if the pins in the plug get moisture in they start to corrode causing all kinds of error messages.

djbe.