DLB AC_High_Side_Pressure 6525.8 psi

[Rawze]

What are the symptoms when not trying to fool it?.

After cranking the truck and turning on the A/C to max ...

Does it allow the A/C compressor to kick in for up to about 10 minutes or so after engine is cranked up?, and then dies?.

Does it not kick the compressor on at all?.

Is it commanding the engine fan to run all the time?.

Instead of throwing sensors at it randomly.. Has anyone bothered to purchase a brand new OEM thermistor from a certified stealers$it and measure its resistance across its 2 pins .. and then simply measure the ones installed at either side of the expansion valve to see if they read the roughly same thing at room temperature?.

Has anyone bothered to see what the ambient temp is reading in the engine ECM?.. because this indirectly effects the cab controller A/C system and how it operates, or if it wants to fail the system. Making sure it is not reading too far away from the actual temps outside?.

-== when did this issue start?...

Before replacing the cab module?.

after replacing the cab control module?

.. or was it working normally at one point and stopped?.



and what do you mean by ...

(05-24-2023 )Satch Wrote:  ... I replaced body control module a couple years ago do to a derate in def issue and don't want to replace it again because of this other issue.
...

That statement does not make much sense.- Derates or other problems due to the emissions systems on the engine are not related to the cab module. the cab module also does not have to be replaced, or re-programmed, if someone de-mandated (made a delete) to the engine... so your statement makes no sense to me.

also.. here is an older post that talks about about the A/C systems on navistar trucks...
http://rawze.com/forums/showthread.php?t...4#pid40694