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VSA DTC Troubleshooting: 68-21

DTC 68-21:
 Brake Pedal Position Switch Stuck OFF
  1. Turn the ignition switch to ON (II).
  1. Check the BRAKE PRESS in the VSA DATA LIST with the HDS. Do not press the brake pedal.
Is there 10 MPa or less?
YES -
Go to Step 3 .
NO -
Check for brake drag or a misadjusted brake pedal position switch. If they are normal, go to Step 20 .
  1. Check the BRAKE SWITCH in the VSA DATA LIST with the HDS while moving the brake pedal.
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. Check for loose terminals between the brake pedal position switch 4P connector, ECM/PCM connector A (49P), and the VSA modulator-control unit 36P connector. Refer to intermittent failures troubleshooting.
NO -
Go to Step 4 .
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect the brake pedal position switch 4P connector.
  1. Connect brake pedal position switch 4P connector terminals No. 1 and No. 2 with a jumper wire.
  1. Turn the ignition switch to ON (II).
  1. Check the BRAKE SWITCH in the VSA DATA LIST with the HDS.
Does it indicate ON?
YES -
Check the brake pedal position switch adjustment. If it is OK, replace the brake pedal position switch .■
NO -
Go to Step 9 .
  1. Disconnect the jumper wire.
  1. Turn the ignition switch to LOCK (0).
  1. Check the No. 24 (15 A) fuse in the under-hood fuse/relay box.
Is the fuse blown?
YES -
Go to Step 12 .
NO -
Reinstall the checked fuse, then go to Step 16 .

  1. Check for continuity between brake pedal position switch 4P connector terminal No. 1 and body ground.
Is there continuity?
YES -
Repair short to body ground in the wire between the No. 24 (15 A) fuse in the under-hood fuse/relay box and the brake pedal position switch.■
NO -
Go to Step 13 .
  1. Short the SCS line with the HDS.
  1. Disconnect ECM/PCM connector A (49P).

  1. Check for continuity between brake pedal position switch 4P connector terminal No. 2 and body ground.
Is there continuity?
YES -
Repair short to body ground in the wire between the brake pedal position switch and the ECM/PCM.■
NO -
Install a new No. 24 (15 A) fuse in the under-hood fuse/relay box, then go to Step 18 .
  1. Short the SCS line with the HDS.
  1. Disconnect ECM/PCM connector A (49P).

  1. Measure the voltage between brake pedal position switch 4P connector terminal No. 1 and body ground.
Is there battery voltage?
YES -
Go to Step 19 .
NO -
Repair open in the wire between the No. 24 (15 A) fuse in the under-hood fuse/relay box and the brake pedal position switch.■

  1. Check for continuity between brake pedal position switch 4P connector terminal No. 2 and ECM/PCM connector A (49P) terminal No. 42.
Is there continuity?
YES -
Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then go to Step 1 and recheck. If the ECM/PCM was updated and DTCs are not indicated, troubleshooting is complete. If the ECM/PCM was substituted and DTCs are not indicated, replace the original ECM/PCM.
NO -
Repair open in the wire between the ECM/PCM and the brake pedal position switch.■
  1. Test-drive the vehicle. Drive the vehicle at 10 km/h (7 mph) or more.
    NOTE: Drive the vehicle on a straight section of road, not on a lift.
  1. Check for DTCs with the HDS.
Is DTC 68-21 indicated?
YES -
Check for loose terminals in the VSA modulator-control unit 36P connector. If the VSA modulator-control unit was updated, substitute a known-good VSA modulator-control unit, then retest. If the VSA modulator-control unit was substituted, go to Step 1 .
NO -
If the VSA modulator-control unit was updated, troubleshooting is complete. If the VSA modulator-control unit was substituted, replace the original VSA modulator-control unit. If any other DTCs are indicated, go to the indicated DTCs troubleshooting.■