DTC U0424-81: HVAC Control Module to Hybrid Powertrain Control Module Invalid Serial Data Received [10/2020 - 10/2023]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Enter the following menus: Body Electrical / Air Conditioner / Trouble Codes.
4. Check if DTCs related to the air conditioning system (A/C) are output.

   Body Electrical > Air Conditioner > Trouble Codes 

   Result

   Result	Proceed to
   DTCs related to A/C are not output.	A
   DTCs related to A/C are output.	B

5. Turn the power switch off.

Result: 

A 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [10/2017 - ] 

Result: 

B 

GO TO DTC CHART (AIR CONDITIONING SYSTEM). Refer to  DIAGNOSTIC TROUBLE CODE CHART [10/2020 - 11/2021]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [11/2021 - 10/2023]