DTC Troubleshooting: P0703
DTC P0703: Brake Pedal Position Switch (NC) Malfunction
NOTE:
Before you troubleshoot, review the general troubleshooting information.
If the accelerator pedal is pressed with pressing the brake pedal lightly and continuously for 5 minutes or more, this DTC will be stored.

DTC Description
Confirmed DTC
Pending DTC
P0703 Brake Pedal Position Switch (NC) Malfunction
   

1.
Brake pedal position switch signal (BKSWNC) check 1:

Brake pedal position switch signal (BKSWNC) check 1
?1.
Turn the vehicle to the ON mode.

?2.
Check the parameter(s) below with the HDS without pressing the brake pedal.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
CRUISE BRAKE SW/IDLE STOP SW
CLOSE
      

Do the current condition(s) match the threshold?

     
YES
     
     
     
Go to step 7.
     
NO
     
     
     
Go to step 2.
2.
Brake pedal position switch installation check:

Brake pedal position switch installation check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Adjust the brake pedal and the brake pedal position switch.

?3.
Turn the vehicle to the ON mode.

?4.
Check the parameter(s) below with the HDS without pressing the brake pedal.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
CRUISE BRAKE SW/IDLE STOP SW
CLOSE
      

Do the current condition(s) match the threshold?

     
YES
     
     
     
The failure is not duplicated.?
     
NO
     
     
     
Go to step 3.
3.
Determine possible failure area (brake pedal position switch, others):

Determine possible failure area (brake pedal position switch, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Brake pedal position switch 4P connector

?3.
Connect terminals A and B with a jumper wire.
Terminal A
Brake pedal position switch 4P connector No. 3
Terminal B
Brake pedal position switch 4P connector No. 4


?4.
Turn the vehicle to the ON mode.

?5.
Check the parameter(s) below with the HDS.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
CRUISE BRAKE SW/IDLE STOP SW
CLOSE
      

Do the current condition(s) match the threshold?

     
YES
     
     
     
     
NO
     
     
     
Go to step 4.
4.
Determine possible failure area (IG1 ACG line, others):

Determine possible failure area (IG1 ACG line, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Remove the jumper wire from the brake pedal position switch 4P connector.

?3.
Turn the vehicle to the ON mode.

?4.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Brake pedal position switch 4P connector: disconnected
Test point 1
Brake pedal position switch 4P connector No. 4
Test point 2
Body ground


Is there battery voltage?

     
YES
     
     
     
The IG1 ACG wire is OK. Go to step 5.
     
NO
     
     
     
Go to step 6.
5.
Open wire check (BKSWNC line):

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

?2.
Jump the SCS line with the HDS, and wait more than 1 minute.


?3.
Disconnect the following connector.
PCM connector A (50P)

?4.
Connect terminals A and B with a jumper wire.
Terminal A
Brake pedal position switch 4P connector No. 3
Terminal B
Brake pedal position switch 4P connector No. 4


?5.
Turn the vehicle to the ON mode.

?6.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Brake pedal position switch 4P connector: disconnected
Brake pedal position switch 4P connector No. 3 and No. 4: jumped
PCM connector A (50P): disconnected
Test point 1
PCM connector A (50P) No. 49
Test point 2
Body ground

Is there battery voltage?

     
YES
     
     
     
The BKSWNC wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM, then recheck. If DTC P0703 goes away and the PCM was substituted, replace the original PCM.?
     
NO
     
     
     
Repair an open in the BKSWNC wire between the PCM (A49) and the brake pedal position switch.?
6.
Fuse check:

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

?2.
Check the following fuse.
Fuse
No. B21 (10 A)
Location
Under-dash fuse/relay box

Is the fuse OK?

     
YES
     
     
     
Repair an open in the IG1 ACG wire between the No. B21 (10 A) fuse and the brake pedal position switch.?
     
NO
     
     
     
Replace the No. B21 (10 A) fuse. Also check for a short to ground on the No. B21 (10 A) fuse circuit if needed.?
7.
Brake pedal position switch signal (BKSWNC) check 2:

Brake pedal position switch signal (BKSWNC) check 2
?1.
Turn the vehicle to the ON mode.

?2.
Press the brake pedal.

?3.
Check the parameter(s) below with the HDS while pressing the brake pedal.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
CRUISE BRAKE SW/IDLE STOP SW
OPEN
      

Do the current condition(s) match the threshold?

     
YES
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the brake pedal position switch and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot.?
     
NO
     
     
     
Go to step 8.
8.
Brake pedal position switch check:

Brake pedal position switch check
?1.
Test the brake pedal position switch.

Is the brake pedal position switch OK?

     
YES
     
     
     
The brake pedal position switch is OK. Repair a short to power in the BKSWNC wire between the PCM (A49) and the brake pedal position switch.?
     
NO