DTC Troubleshooting: C1421-14
DTC C1421-14: Main Torque Sensor Malfunction
NOTE: Before you troubleshoot, review the how to troubleshoot the EPS.

DTC Description
DTC
Freeze Frame
C1421-14 Main Torque Sensor Malfunction
    

1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the OFF (LOCK) mode, then 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.
Turn the steering wheel to the right and left several times.

?5.
Check for DTCs with the HDS.
DTC Description
DTC
Freeze Frame
C1421-14 Main Torque Sensor Malfunction
    

Is DTC C1421-14 indicated?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. 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.
Torque sensor performance check:

Torque sensor performance check
?1.
Turn the steering wheel to the right and left several times.

?2.
Check the parameter(s) below with the HDS.
Signal
Current conditions
Values
Unit
TORQUE SENSOR MAIN
    

Is there less than about 0.3 V or more than about 4.8 V?

     
YES (less than about 0.3 V)
     
     
     
Go to step 3.
     
YES (More than about 4.8 V)
     
     
     
Go to step 9.
     
NO
     
     
     
Check for loose terminals and poor connections at the EPS control unit connectors. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting. If they are OK, replace the EPS motor/control unit.?
3.
Open wire check (T/S VDD line) 1:

Open wire check (T/S VDD line) 1
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Torque sensor 6P connector

?3.
Turn the vehicle to the ON mode.

?4.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
Torque sensor 6P connector: disconnected
Test circuit
T/S VDD
Test point 1
Torque sensor 6P connector No. 5
Test point 2
Body ground


Is there about 5 V?

     
YES
     
     
     
The T/S VDD wire is OK. Go to step 6.
     
NO
     
     
     
Go to step 4.
4.
Open wire check (T/S VDD line) 2:

Open wire check (T/S VDD line) 2
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
EPS control unit connector C (4P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
EPS control unit connector C (4P): disconnected
 
Torque sensor 6P connector: disconnected
Test point 1
EPS control unit connector C (4P) No. 2
Test point 2
Torque sensor 6P connector No. 5


Is there continuity?

     
YES
     
     
     
The T/S VDD wire is not open. Go to step 5.
     
NO
     
     
     
Repair an open in the wire between the EPS control unit and the torque sensor.?
5.
Shorted wire check (T/S VDD line):

Shorted wire check (T/S VDD line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Torque sensor 6P connector: disconnected
Test circuit
T/S VDD
Test point 1
Torque sensor 6P connector No. 5
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short to body ground in the wire between the EPS control unit and the torque sensor.?
     
NO
     
     
     
Check for loose terminals and poor connections at the EPS control unit connectors. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting. If they are OK, replace the EPS motor/control unit.?
6.
Torque sensor check:

Torque sensor check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Torque sensor 6P connector

?3.
Connect terminals A and B with a jumper wire.
Terminal A
Torque sensor 6P connector No. 2
Terminal B
Torque sensor 6P connector No. 5


?4.
Start the engine.

?5.
Check the parameter(s) below with the HDS.
Signal
Current conditions
Values
Unit
TORQUE SENSOR MAIN
    

Is there about 5 V?

     
YES
     
     
     
     
NO
     
     
     
Go to step 7.
7.
Open wire check (TSM line):

Open wire check (TSM line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
EPS control unit connector C (4P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
EPS control unit connector C (4P): disconnected
 
Torque sensor 6P connector: disconnected
Test point 1
EPS control unit connector C (4P) No. 3
Test point 2
Torque sensor 6P connector No. 2


Is there continuity?

     
YES
     
     
     
The TSM wire is not open. Go to step 8.
     
NO
     
     
     
Repair an open in the wire between the torque sensor and the EPS motor/control unit.?
8.
Shorted wire check (TSM line):

Shorted wire check (TSM line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
EPS control unit connector C (4P): disconnected
 
Torque sensor 6P connector: disconnected
Test point 1
Torque sensor 6P connector No. 2
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short to body ground in the wire between the torque sensor and the EPS motor/control unit.?
     
NO
     
     
     
The TSM wire is OK. Check for loose terminals and poor connections at the EPS control unit connectors. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting. If they are OK, replace the EPS motor/control unit.?
9.
Torque sensor check:

Torque sensor check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Torque sensor 6P connector

?3.
Start the engine.

?4.
Check the parameter(s) below with the HDS.
Signal
Current conditions
Values
Unit
TORQUE SENSOR MAIN
    

Is there about 0 V ?

     
YES
     
     
     
     
NO
     
     
     
Go to step 10.
10.
Shorted wire check (TSM line to T/S VDD line):

Shorted wire check (TSM line to T/S VDD line)
?1.
Turn the vehicle to the OFF (LOCK) mode, then to the ON mode.

?2.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
Torque sensor 6P connector: disconnected
Test point 1
Torque sensor 6P connector No. 2
Test point 2
Body ground

Is there about 5 V?

     
YES
     
     
     
Repair a short to power in the wire between the torque sensor and the EPS motor/control unit.?
     
NO
     
     
     
The TSM wire is not shorted. Go to step 11
11.
Open wire check (T/S GND line):

Open wire check (T/S GND line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
EPS control unit connector C (4P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
EPS control unit connector C (4P): disconnected
 
Torque sensor 6P connector: disconnected
Test point 1
EPS control unit connector C (4P) No. 1
Test point 2
Torque sensor 6P connector No. 3


Is there continuity?

     
YES
     
     
     
The T/S GND wire is OK. Check for loose terminals and poor connections at the EPS control unit connectors. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting. If they are OK, replace the EPS motor/control unit.?
     
NO
     
     
     
Repair an open in the wire between the torque sensor and the EPS motor/control unit.?