t800 codes 3,4 and 12

[BurkeBev]

hellow, i got an issue on my less then 2 years old TK t800. i have alarm codes 3 and 4 which is return air sensor and discharge air sensor, respectively. i also have code 12 :sensor or digital input shutdown.
i have done a visual inspection on the unit and have found no issues. i have also checked all fuses and did not find anything blown.

whats throwing me off is that on the control pad i can pull up the sensors and see that they are functional and reading correctly. yet i cannot clear the codes. any help or input would be appreciated.

[wop]

Have you checked the plug at the micro. The ts500's were bad for the pins being squished and not making contact all the time and putting up those codes. Split the pins with an exacto knife and it solves it. Don't know if that applies to the t800's yet. We haven't had that happen.....YET.lol. Good luck.

[wop]

If its an sr2 you will have to get into guarded access to clear the codes. If the truck doesn't have the sr2 controller then you will probably have to clear them using wintrac.

[BurkeBev]

yes, i checked the pins. pins are good and making solid contact.
i have a sister unit that had a bad controller that was replaced. i tried swapping the controller with the sister unit to see if it was an issue with the controller. the issue stayed with the original unit. i have the premium HMI controller.

[BurkeBev]

another question, how do i go about setting the sensor grade using the sr-3 controller? TK told me it can be done from the controller.

[BurkeBev]

update:
i was going to replace the sensors and while at the dealer i asked a tech on how to set the grade and also how to get into guarded access. i got into guarded access and cleared the codes. the unit is now operating normally. i will give it a week to see if the alarm codes return. wish me luck, those sensors are expensive.

[swampy84]

I have seen multiple issues with the sensor interconnect plug that sits behind the compressor
Starts off as DTP, DTN -01 etc, connects into a deutsch plug behind the compressor where it then turns into DTP, DTN -02 etc. all it takes is a slight voltage issue to bring up a sensor code and they'll stay until cleared in guarded access.

[swampy84]

All sensors need to be between 4.9 to 5.1 V