DTC 68-12

DTC 68-12  : Brake Pedal Position Switch Stuck ON

NOTE: Before you troubleshoot, review the general troubleshooting information .

DTCs (VSA)

1. VSA modulator-control unit performance check

   -1. Start the engine.

   -2. Check the parameter(s) below with the HDS. Do not press the brake pedal.

   Signal	Current conditions
   	Values	Unit
   BRAKE PRESSURE

   Is there 10 MPa or more?

   YES 

   Go to step 2.

   NO 

   Go to step 3.

2. Brake pedal height check

   -1. Check the brake pedal height .

   Is the brake pedal height OK?

   YES 

   Go to step 8.

   NO 

   Adjust the brake pedal height .

3. Brake pedal position switch performance check 1

   -1. Check the parameter(s) below with the HDS while pressing the brake pedal.

   Signal	Current conditions
   	Values	Unit
   BRAKE SWITCH

   Does it indicate ON when the pedal is pressed, and OFF when the pedal is released?

   YES 

   Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting .

   NO 

   Go to step 4.

4. Brake pedal position switch performance check 2

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the following connector.

   Brake pedal position switch 4P connector

   -3. Turn the vehicle to the ON mode.

   -4. Check the parameter(s) below with the HDS.

   Signal	Current conditions
   	Values	Unit
   BRAKE SWITCH

   Does the indicator change from ON to OFF?

   YES 

   Replace the brake pedal position switch .

   NO 

   Go to step 5.

5. Shorted wire check (BRK DIAG line to power)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Short the SCS line with the HDS.

   NOTE:  Always short the SCS line with the HDS before removing PCM connector(s).

   -3. Disconnect the following connector.

   PCM connector A (51P)

   Brake light relay

   -4. Turn the vehicle to the ON mode.

   -5. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	Brake pedal position switch 4P connector: disconnected
   	PCM connector A (51P): disconnected
   	Brake light relay: disconnected
   Test point 1	Brake pedal position switch 4P connector No. 1
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there 0.1 V or more?

   YES 

   Repair a short to power in the BRK DIAG wire between the PCM and/or brake light relay the brake pedal position switch. Go to step 6.

   NO 

   The BRK DIAG wire is OK. Go to step 7.

6. Shorted wire check (STOP SW line to power)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Reconnect the following connectors.

   Brake pedal position switch 4P connector

   PCM connector A (51P)

   -3. Disconnect the following connector.

   VSA modulator-control unit 21P connector

   -4. Turn the vehicle to the ON mode.

   -5. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	Brake light relay: disconnected
   	VSA modulator-control unit 21P connector: disconnected
   Test point 1	VSA modulator-control unit 21P connector No. 7

   Test point 2

   Body ground

   Is there 0.1 V or more?

   YES 

   Repair a short to power in the STOP SW wire between the brake light relay and the VSA modulator-control unit 21P connector.

   NO 

   The STOP SW wire is OK. Go to step 7.

7. PCM check (update or substitution)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Reconnect the following connectors.

   Brake pedal position switch 4P connector

   PCM connector A (51P)

   -3. Update the PCM if it does not have the latest software , or substitute a known-good PCM .

   -4. Turn the vehicle to the ON mode.

   -5. Clear the DTC with the HDS.

   -6. Turn the vehicle to the OFF (LOCK) mode, then to the ON mode.

   -7. Check for DTCs with the HDS.

   DTC Description	DTC	Freeze Frame
   68-12 Brake Pedal Position Switch Stuck ON

   Is DTC 68-12 indicated?

   YES 

   Go to step 8.

   NO 

   If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM .

8. 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 to the ON mode.

   -3. Check for DTCs with the HDS.

   DTC Description	DTC	Freeze Frame

   Is DTC 68-12 indicated?

   YES 

   Check for loose terminals in the VSA modulator-control unit 21P 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.