Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC U0427: Invalid Data Received From Vehicle Security Control Module
DTC detecting condition:
Defective data was transmitted from keyless access control module.
Trouble symptom:
keyless access does not operate properly.
Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to LAN SYSTEM (DIAGNOSTICS) (HEV)>GENERAL DESCRIPTION>CAUTION .
- CHECK CAN COMMUNICATION HARNESS
.
Perform the basic diagnostic procedure to check for fault in CAN communication harness. Ref. to LAN SYSTEM (DIAGNOSTICS) (HEV)>BASIC DIAGNOSTIC PROCEDURE .
Was the basic diagnostic procedure performed up to step 7?
Yes: Go to 2.
No: Perform the basic diagnostic procedure. Ref. to LAN SYSTEM (DIAGNOSTICS) (HEV)>BASIC DIAGNOSTIC PROCEDURE .
- CHECK DTC (OTHER THAN U-CODE)
.
Check the displayed DTC.
Is DTC other than U*** displayed? (Current malfunction)
Yes: Perform the diagnosis for the displayed DTCs other than U-code.
No: Go to 3.
- CHECK DTC (U-CODE)
.
Check the displayed DTC.
Is DTC for the bus off or the data no-receive displayed? (Current malfunction)
Yes: Perform the diagnosis for DTCs for the displayed bus off or the data no-receive.
No: Go to 4.
- CHECK DTC
.
Check the displayed DTC.
Is DTC U0427 displayed? (Current malfunction)
Yes: Go to 5.
No: Go to 7.
- CHECK DTC
.
- Turn the ignition switch to OFF.
- Disconnect the keyless access control module connector.
- Connect the disconnected connectors.
- Turn the ignition switch to ON.
- Using the Subaru Select Monitor, read all DTCs. Ref. to LAN SYSTEM (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .
Is DTC U0427 displayed? (Current malfunction)
Yes: Go to 6.
No: Go to 7.
- CHECK DTC
.
Using the Subaru Select Monitor, read all DTCs. Ref. to LAN SYSTEM (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .
Is DTC U0427 detected in several modules? (Current malfunction)
Yes: Replace the keyless access control module. Ref. to SECURITY AND LOCKS>KEYLESS ACCESS CONTROL MODULE .
No: Replace the module that the DTC has been detected.
- CHECK HARNESS
.
- Shake the harness, and check for poor contact.
- Using the Subaru Select Monitor, read all DTCs. Ref. to LAN SYSTEM (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .
Is DTC U0427 displayed? (Current malfunction)
Yes: Repair the poor contact of harness, or replace the harness.
No: Go to 8.
- CHECK CONNECTOR
.
Check the connector used for high speed CAN for poor contact.
Is there poor contact of connector?
Yes: Repair the connector that has poor contact, or replace harness.
No: It is possible that temporary poor communication occurs. Delete the DTC.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.