DTC U0424-81: HVAC Control Module to Hybrid Powertrain Control Module Invalid Serial Data Received [01/2019 - 09/2022]: Procedure

WARNING: This page is about a different car, the 2022 Toyota Corolla, 2021 Toyota Corolla, and 2020 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.

CHECK DTC OUTPUT (AIR CONDITIONER)

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Enter the following menus: Body Electrical / Air Conditioner / Trouble Codes.

Check for DTCs.

Body Electrical > Air Conditioner > Trouble Codes

Result

Result	Proceed to
No DTCs are output	A
DTCs are output	B

Turn the power switch off.

Result:

A

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to REMOVAL [01/2019 - 09/2022]

Result:

B

GO TO DTC CHART (AIR CONDITIONING SYSTEM). Refer to DIAGNOSTIC TROUBLE CODE CHART [01/2019 - 04/2020] , or refer to DIAGNOSTIC TROUBLE CODE CHART [04/2020 - 09/2022]