Nissan Maxima Service and Repair Manual: ASCD brake switch

Nissan Maxima Service and Repair Manual / Engine / Engine control system / DTC/circuit diagnosis / ASCD brake switch

Description

When the brake pedal is depressed, ASCD brake switch is turned OFF and stop lamp switch is turned ON.

ECM detects the state of the brake pedal by those two types of input (ON/OFF signal).

Refer to EC-68, "System Diagram" for the ASCD function.

Component Function Check

1.CHECK ASCD BRAKE SWITCH FUNCTION

With CONSULT

  1. Turn ignition switch ON.
  2. Select "BRAKE SW1" in "DATA MONITOR" mode with CONSULT.
  3. Check "BRAKE SW1" indication under the following conditions.

Nissan Maxima. CHECK ASCD BRAKE SWITCH FUNCTION

Without CONSULT

Nissan Maxima. CHECK ASCD BRAKE SWITCH FUNCTION

  1. Turn ignition switch ON.
  2. Check the voltage between ECM harness connectors

Nissan Maxima. CHECK ASCD BRAKE SWITCH FUNCTION

Diagnosis Procedure

1.CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT

Nissan Maxima. CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT

  1. Turn ignition switch OFF.
  2. Disconnect ASCD brake switch harness connector.
  3. Turn ignition switch ON.
  4. Check the voltage between ASCD brake switch harness connector and ground.

Nissan Maxima. CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT

2.DETECT MALFUNCTIONING PART

Check the following.

  • Fuse block (J/B) connector E6
  • Junction block connectors E44, E46
  • 10 A fuse (No. 3)
  • Harness for open or short between ASCD brake switch and fuse

3.CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

  1. Turn ignition switch OFF.
  2. Disconnect ECM harness connector.
  3. Check the continuity between ASCD brake switch harness connector and ECM harness connector.
  4. Also check harness for short to ground and short to power.

Nissan Maxima. CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

4.DETECT MALFUNCTIONING PART

Check the following.

  • Junction block connectors E45, E46
  • Harness for open or short between ASCD brake switch and ECM

5.CHECK ASCD BRAKE SWITCH

6.CHECK INTERMITTENT INCIDENT

Component Inspection (ASCD Brake Switch)

1.CHECK ASCD BRAKE SWITCH-I

Nissan Maxima. CHECK ASCD BRAKE SWITCH-I

  1. Turn ignition switch OFF.
  2. Disconnect ASCD brake switch harness connector.
  3. Check the continuity between ASCD brake switch terminals under the following conditions.

Nissan Maxima. CHECK ASCD BRAKE SWITCH-I

2.CHECK ASCD BRAKE SWITCH-II

Nissan Maxima. CHECK ASCD BRAKE SWITCH-II

  1. Adjust ASCD brake switch installation. Refer to BR-14, "Inspection and Adjustment".
  2. Check the continuity between ASCD brake switch terminals under the following conditions

Nissan Maxima. CHECK ASCD BRAKE SWITCH-II

    P2138 APP sensor

    ASCD indicator