VSA DTC Troubleshooting: 66

DTC 66:
 VSA Pressure Sensor (Software)
  1. Turn the ignition switch to ON (II).
  1. Check for DTCs with the HDS.
Is DTC 91 or 92 indicated with DTC 66 at the same time?
YES -
Do the DTC 91 or 92 troubleshooting: DTC 91, DTC 92.
NO -
Go to Step 3 .
  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?
YES -
Go to Step 4 .
NO -
Go to Step 13 .
  1. Turn the ignition switch to LOCK (0).
  1. Check the No. 21 (15 A) fuse in the under-hood fuse/relay box.
Is the fuse blown?
YES -
Install a new No. 21 (15 A) fuse, and recheck.■
NO -
Reinstall the checked fuse, then go to Step 6 .
  1. Disconnect the brake pedal position switch 4P connector.
Is the switch OK?
YES -
Go to Step 8 .
NO -
  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 9 .
NO -
Repair open in the wire between the No. 21 (15 A) fuse in the under-hood fuse/relay box and the brake pedal position switch.■
  1. Reconnect the brake pedal position switch 4P connector.
  1. Short the SCS line with the HDS.
  1. Disconnect the ECM connector A (49P) (L13Z1 engine model) or ECM connector A (44P) (except L13Z1 engine model).

  1. Measure the voltage between ECM connector A (49P) terminal No. 42 (L13Z1 engine model) or ECM connector A (44P) terminal No. 40 (except L13Z1 engine model) and body ground.
Is there battery voltage when the brake pedal is pressed?
YES -
Check for loose terminals in the ECM connector A (49P) (L13Z1 engine model) or ECM connector A (44P) (except L13Z1 engine model). If necessary, substitute a know-good ECM and retest: L13Z1 engine model, R18A2 engine model, K20Z4 engine model.
NO -
Repair open in the wire between the ECM and the brake pedal position switch.■
  1. Turn the ignition switch to ON (II).
  1. Clear the DTC with the HDS.
  1. Press the brake pedal several times.
  1. Check for DTCs with the HDS.
Is DTC 66 indicated?
YES -
Go to Step 17 .
NO -
Intermittent failure, the system is OK at this time. Check for loose terminals between the brake pedal position switch 4P connector, the ECM connector A (49P) (L13Z1 engine model) or ECM connector A (44P) (except L13Z1 engine model), and the VSA modulator-control unit 46P connector. Refer to intermittent failures troubleshooting.
  1. Check the BRK PRESS in the VSA DATA LIST with the HDS while moving the brake pedal.
Does the pressure increase when the pedal is pressed, and decrease when the pedal is released?
YES -
Check for loose terminals in the VSA modulator-control unit 46P connector. If necessary, substitute a known-good VSA modulator-control unit and retest.■
NO -