Hello, relatively new to the X300 space here, I own a 3.2 XJ6, in jade green which I bought several weeks ago, and loving every bit of it!

Recently, I had the A/C error display occur, and upon looking through the stored error codes on the system, error codes 12 and 23 came up. After getting serviced by my mechanic, a regas was performed to clear it, however still present are both error codes 12 and 23

Knowing that, referring to the climate control error page.
Error code 12 is
"Ambient temperature sensor malfunction Harness / connector fault Sensor open / short circuit"
and 23 is
"Refrigerant pressure switch malfunction Harness / connector fault Switch open / short circuit Refer to PDU23 Refrigerant pressure low refrigerant charge".

What would be my best course of action now? I'm not too sure how to proceed.

 

The ambient temp sensor is located fwd of the left fwd wheel in the brake cooling duct that runs from your front bumper

You can clean that connector at the sensor

The low freon switch is the 4 wire connector on the freon lines very near the rear engine firewall

this is a grounding wire switch and you can clean the ground point at X , these are 2 black wires with one for the low pressure switch of a 2 switch can

You will see a different 2 wire connector on a seperate freon pressure switch can fwd of the 4 wire connector switch can

This 2 wire connector may have been removed by a TSB , this TSB only effects your radiator cooling fan operation which has an effect on your A / C performance amount or cooling effect at standstill car motion

T703 BOOK (jagrepair.com)

 

i had a malfunction of my ambient temp sensor and then realized it was missing.
picked up a cooling duct + sensor from a wreckers and all good.

i also had a code (can't remember which one) regarding the AC refrigerant. it may have been low pressure, after clearing the codes this one never came back.

i suspect it had previously had been regassed but not had the codes cleared after that.

so i would suggest, clear the codes,
run the car for a bit,
check codes again
and see if 23 comes back or stays away

and for code 12 check if the temp sensor is even there. mine wasn't.

 

climate control diag pdf attached