ASCD Brake/BRAKELIGHT Switch Check: Sentra

Turn ignition off. Disconnect ASCD control unit harness connector. Check continuity between terminal No. 8 (Purple/Blue wire) and No. 12 (Brown/Yellow wire) on ASCD control unit harness connector. See Figure. Continuity should exist when gearshift selector is in any position except Park or Neutral (A/T), and clutch (M/T) and brake pedal are released. Continuity should not exist when brake pedal is depressed and gearshift selector is in Park or Neutral (A/T) position or clutch (M/T) is depressed. If continuity is as specified, go to next step. If continuity is not as specified, check the following. Repair or replace component as needed. If no problems are found, replace ASCD control unit.
- Check brake switch. See ASCD BRAKE & STOPLIGHT SWITCHES under COMPONENT TESTS.
- Check clutch switch (M/T). See ASCD CLUTCH SWITCH (M/T) under COMPONENT TESTS.
- Inspect Park/Neutral Position relay. See PARK/NEUTRAL POSITION RELAY . Replace as needed.
- Check Park/Neutral Position (PNP) switch (A/T). See PARK/NEUTRAL POSITION (PNP) SWITCH (A/T) under COMPONENT TESTS.
- Check related wiring harness for open or short circuits. See WIRING DIAGRAMS .
Measure voltage between ground and terminal No. 23 (Red/Green wire) on ASCD control unit harness connector. Battery voltage should be present with brake pedal depressed, and zero volts with brake pedal released. If voltage is not as specified, go to next step. If voltage is as specified, brake/brakelight switches and circuits are okay.
Check fuse No. 2 (10-amp) located in fuse block. Check for open or short in wiring harness between ASCD control unit and brakelight switch, and between brakelight switch and fuse No. 2 (10-amp). See WIRING DIAGRAMS . Repair as necessary. Check brakelight switch. See ASCD BRAKE & BRAKELIGHT SWITCHES under COMPONENT TESTS. Replace as necessary.