DTC U0401-81: Invalid Data Received from ECM/PCM "A" Invalid Serial Data Received [01/2023 - ]: Procedure

1. Clear the DTCs.

   Powertrain > Radar Cruise2 > Clear DTCs 

2. Make sure that the DTC detection conditions are met.

   HINT: 

   If the detection conditions are not met, the system cannot detect the malfunction.

3. Check for DTCs.

   Powertrain > Radar Cruise2 > Trouble Codes 

   Result

   Result	Proceed to
   DTC U0401-81 is not output	A
   DTC U0401-81 is output	B

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [01/2023 - ] 

Result: 

B 

REPLACE ECM. Refer to  REMOVAL [09/2014 - ]