Suzuki Vitara (LY) 2016-2017 · Service Manual M16A · Diagnostic Information and Procedures

DTC U2021

Precautions: General safety (00)

DTC Detecting Condition and Trouble Area
DTC detecting condition Trouble area
U2021: LIN Invalid Data from ECM to Generator
Transmitted data from ECM to generator via LIN is faulty.
(1 D/C detection logic but MIL does not light up)
•ECM power supply circuit and/or ground circuit
•ECM
DTC Confirmation Procedure
1)Set ignition “ON”.
DTC Troubleshooting
Step Action Yes No
1
DTC recheck
1)Clear DTC. icon 
2)Set ignition “OFF”.
3)Perform “DTC Confirmation Procedure” and check DTC.
Is DTC U2021 still detected?
Go to Step 2.
Check for intermittent trouble. icon 
2
ECM power supply and ground circuit check
1)Check ECM power supply and ground circuits. icon 
Is check result OK?
Replace ECM and recheck DTC. icon 
Repair ECM power supply and ground circuits.