DTC Troubleshooting: C1020-49, C1021-49
DTC C1020-49: VSA Master Cut Valve Failure (Unexpected Operation)
DTC C1021-49: VSA Suction Valve Failure (Unexpected Operation)
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
DTC
Freeze Frame
C1020-49 VSA Master Cut Valve Failure (Unexpected Operation)
    
C1021-49 VSA Suction Valve Failure (Unexpected Operation)
    

1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Turn the vehicle to the OFF (LOCK) mode, then start the engine.

?4.
Wait 20 seconds or more.

?5.
Test-drive the vehicle at 10 mph (15 km/h) or more.
NOTE: Drive the vehicle on the road, not on a lift.

?6.
Check for DTCs with the HDS.
DTC Description
DTC
Freeze Frame
C1020-49 VSA Master Cut Valve Failure (Unexpected Operation)
    
C1021-49 VSA Suction Valve Failure (Unexpected Operation)
    

Is DTC C1020-49 or C1021-49 indicated?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the Freeze data/on-board snapshot.?
2.
VSA modulator-control unit check (update):

VSA modulator-control unit check (update)
?1.
Update the VSA modulator-control unit if it does not have the latest software.

?2.
Turn the vehicle to the OFF (LOCK) mode, then start the engine.

?3.
Wait 20 seconds or more.

?4.
Test-drive the vehicle at 10 mph (15 km/h) or more.
NOTE: Drive the vehicle on the road, not on a lift.

?5.
Check for DTCs with the HDS.
DTC Description
DTC
Freeze Frame
     

Is DTC C1020-49 or C1021-49 indicated?

     
YES
     
     
     
Check for loose terminals and poor connections in the VSA modulator-control unit 38P connector. If the VSA modulator-control unit was updated and the symptom/indication is still present, replace the VSA modulator-control unit.?
     
NO
     
     
     
Troubleshooting is complete. If any other DTCs are indicated, go to the indicated DTCs troubleshooting.?