DTC Troubleshooting: B12C5
DTC B12C5: Engine Start/Stop Switch Failure
NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A.

DTC Description
DTC
B12C5 Engine Start/Stop Switch Failure
  

1.
Problem verification:

Problem verification
?1.
Clear the DTCs with the HDS.


?2.
Press the engine start/stop switch at least twenty times, then wait for at least 20 seconds.

?3.
Check for DTCs with the HDS.
DTC Description
DTC
B12C5 Engine Start/Stop Switch Failure
  

Is DTC B12C5 indicated?

     
YES
     
     
     
Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for loose or poor connections.?
2.
Determine possible failure area (?B SMART line, GND line, other):

Determine possible failure area (?B SMART line, GND line, other)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Engine start/stop switch 10P connector

?3.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Engine start/stop switch 10P connector: disconnected
Test point 1
Engine start/stop switch 10P connector (female terminals) No. 5:
Test point 2
Engine start/stop switch 10P connector (female terminals) No. 1:


Is there battery voltage?

     
YES
     
     
     
The ?B SMART and GND wires are OK. Go to step 3.
     
NO
     
     
     
Go to step 6.
3.
Shorted wire check (SS1 (?), SS2 (?) lines):

Shorted wire check (SS1 (?), SS2 (?) lines)
?1.
Disconnect the following connector.
Body control module connector G (32P)

?2.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Engine start/stop switch 10P connector: disconnected
Body control module connector G (32P): disconnected
Test point 1
Engine start/stop switch 10P connector (female terminals) No. 6:
Test point 2
Body ground

Test point 1
Engine start/stop switch 10P connector (female terminals) No. 10:
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair short to ground in the wire.?
     
NO
     
     
     
The SS1 (?) and SS2 (?) wires are not shorted. Go to step 4.
4.
Open wire check (SS1 (?), SS2 (?) lines):

Open wire check (SS1 (?), SS2 (?) lines)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Engine start/stop switch 10P connector: disconnected
Body control module connector G (32P): disconnected
Test point 1
Engine start/stop switch 10P connector (female terminals) No. 6:
Test point 2
Body control module connector G (32P) No. 18

Test point 1
Engine start/stop switch 10P connector (female terminals) No. 10:
Test point 2
Body control module connector G (32P) No. 9


Is there continuity?

     
YES
     
     
     
The SS1 (?) and SS2 (?) wires are OK. Go to step 5.
     
NO
     
     
     
Repair an open or high resistance in the wire.?
5.
Engine start/stop switch check:

Engine start/stop switch check
?1.
Do the engine start/stop switch test.

Is the engine start/stop switch OK?

     
YES
     
     
     
     
NO
     
     
     
6.
Open wire check (?B SMART line):

Open wire check (?B SMART line)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Engine start/stop switch 10P connector: disconnected
Body control module connector G (32P): disconnected
Test point 1
Engine start/stop switch 10P connector (female terminals) No. 5:
Test point 2
Body ground


Is there battery voltage?

     
YES
     
     
     
Repair an open or high resistance in the GND wire.?
     
NO
     
     
     
Repair an open or high resistance in the ?B SMART wire.?