VSA DTC 59-1 (2014 2015)

DTC 59-1  : Brake Diag Circuit ON Failure

NOTE:  Before you troubleshoot, review the how to troubleshoot the VSA system - Refer to:

How to Troubleshoot the VSA System (2014 2015 2016)

DTCs (VSA)

1. Brake light relay check

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

   - 2. Check the brake lights without pressing the brake pedal.

   Are the brake lights on?

   YES 

   Replace the brake light relay.

   NO 

   Go to step 2.

2. Shorted wire check (BRAKE LAMP line) 1

   - 1. Turn the vehicle to the ON mode.

   - 2. Check the brake lights without pressing the brake pedal.

   Are the brake lights on?

   YES 

   Go to step 3.

   NO 

   Go to step 5.

3. Shorted wire check (BRAKE LAMP line) 2

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

   - 2. Disconnect the following connector.

   VSA modulator-control unit 38P connector

   - 3. Turn the vehicle to the ON mode.

   - 4. Check the brake lights without pressing the brake pedal.

   Are the brake lights on?

   YES 

   Go to step 4.

   YES 

   Repair a short to body ground in the wire between the VSA modulator-control unit 38P connector No. 14 and the brake light relay 5P connector terminal No. 5.

   NO 

   The BRAKE LAMP wire is OK. Go to step 8.

4. Shorted wire check (BRAKE LAMP line) 3

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

   - 2. Disconnect the following connector.

   ACC unit 20P connector

   - 3. Turn the vehicle to the ON mode.

   - 4. Check the brake lights without pressing the brake pedal.

   Are the brake lights on?

   YES 

   Repair a short to body ground in the wire between the VSA modulator-control unit 38P connector No. 14 and the brake light relay 5P connector terminal No. 5, or ACC unit 20P connector No. 11.

   NO 

   Replace the ACC unit .

5. Problem verification

   - 1. Clear the DTC with the HDS.

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

   - 3. Press the brake pedal for 3 seconds or more.

   - 4. Check for DTCs with the HDS.

   DTC Description	DTC	Freeze Frame
   59-1 Brake Diag Circuit ON Failure

   Is DTC 59-1 indicated?

   YES 

   The failure is duplicated. Go to step 6.

   NO 

   The failure is not duplicated. Go to step 8.

6. Open wire check (STOP SW line)

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

   - 2. Short the SCS line with the HDS.

   - 3. Disconnect the following connectors.

   PCM connector A (51P) - Refer to: How to Troubleshoot the Fuel and Emissions Systems (2014-20) or How to Troubleshoot the Fuel and Emissions Systems (With Auto Idle Stop System) (2016-20)

   Brake pedal position switch 4P connector

   - 4. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Brake pedal position switch 4P connector: disconnected
   	PCM connector A (51P): disconnected
   Test circuit	STOP SW
   Test point 1	Brake pedal position switch 4P connector No. 1 (PUR)
   Test point 2	PCM connector A (51P) No. 25 (PUR)

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

   Is there continuity?

   YES 

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

   NO 

   Repair an open in the wire between the PCM and the brake pedal position switch.

7. PCM check (update or substitution)

   - 1. Reconnect the following connectors.

   PCM connector A (51P) - Refer to: How to Troubleshoot the Fuel and Emissions Systems (2014-20) or How to Troubleshoot the Fuel and Emissions Systems (With Auto Idle Stop System) (2016-20)

   Brake pedal position switch 4P connector

   - 2. Update the PCM if it does not have the latest software,

   or substitute a known-good PCM.  Refer to:

   PCM Removal and Installation (2014 2015)

   - 3. Clear the DTC with the HDS.

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

   - 5. Press the brake pedal for 3 seconds or more.

   - 6. Check for DTCs with the HDS.

   DTC Description	DTC	Freeze Frame
   59-1 Brake Diag Circuit ON Failure

   Is DTC 59-1 indicated?

   YES 

   Go to step 8.

   NO 

   If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM - Refer to:

   PCM Removal and Installation (2014 2015)

8. VSA modulator-control unit check (update)

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

   - 2. Reconnect the following connector.

   VSA modulator-control unit 38P connector (if disconnected)

   - 3. Update the VSA modulator-control unit if it does not have the latest software.

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

   - 5. Press the brake pedal for 3 seconds or more.

   - 6. Check for DTCs with the HDS.

   DTC Description	DTC	Freeze Frame

   Is DTC 59-1 indicated?

   YES 

   Check for loose terminals 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.