Test 2: ASCD Brake/BRAKELIGHT Switch Check

Turn ignition switch to LOCK position. Disconnect ASCD control unit harness connector. Turn ignition switch to ON position. Measure voltage between ground and terminal No. 8 (Blue/Yellow wire) at ASCD control unit harness connector. See Figure . When brake pedal is depressed or gear selector lever is in Park or Neutral position, zero volts should exist. When brake pedal is released and gear selector lever is in any position other than Park or Neutral, battery voltage should exist. If voltage is as specified, go to next step. If voltage is not as specified, check the following and repair as necessary:
- Faulty ASCD brake switch. See SWITCHES under COMPONENT TESTS.
- Faulty Park/Neutral Position (PNP) switch. See SWITCHES under COMPONENT TESTS.
- Faulty PNP relay.
- Open or short in wiring harness. See WIRING DIAGRAMS .
Measure voltage between ground and terminal No. 23 (Green/Yellow wire) on ASCD control unit harness connector. When brake pedal is depressed, battery voltage should exist. When brake pedal is released, zero volts should exist. If voltage is as specified, ASCD brake/brakelight switch is okay at this time. If voltage is not as specified, check the following and repair as necessary:
- Faulty fuse No. 14 (10-amp) in instrument panel fuse box.
- Open or short in harness between ASCD control unit and brakelight switch. See WIRING DIAGRAMS .
- Faulty brakelight switch. See SWITCHES under COMPONENT TESTS.