Nissan Maxima Service and Repair Manual: P1805 brake switch

Description

Brake switch signal is applied to the ECM via the stop lamp switch when the brake pedal is depressed. This signal is used mainly to decrease the engine speed when the vehicle is being driver.

DTC Logic

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.PERFORM DTC CONFIRMATION PROCEDURE

1. Turn ignition switch ON.
2. Fully depress the brake pedal for at least 5 seconds.
3. Erase the DTC.
4. Check 1st trip DTC.

Diagnosis Procedure

1.CHECK STOP LAMP SWITCH CIRCUIT

1. Turn ignition switch OFF.
2. Check the stop lamp when depressing and releasing the brake pedal.

2.CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT

1. Disconnect stop lamp switch harness connector.
2. Check the voltage between stop lamp switch harness connector and ground.

3.DETECT MALFUNCTIONING PART

Check the following.

• Fuse block (J/B) connector E6
• 10 A fuse (No. 7)
• Harness for open or short between battery and stop lamp switch

4.CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Disconnect stop lamp switch harness connector.
2. Disconnect ECM harness connector.
3. Check the continuity between stop lamp switch harness connector and ECM harness connector.
4. Also check harness for short to ground and short to power.

5.DETECT MALFUNCTIONING PART

Check the following.

• Fuse block (J/B) connector E6
• Junction block connectors E44, E45
• Harness for open or short between ECM and stop lamp switch

6.CHECK STOP LAMP SWITC

7.CHECK INTERMITTENT INCIDENT

Component Inspection (Stop Lamp Switch)

1.CHECK STOP LAMP SWITCH-I

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

2.CHECK STOP LAMP SWITCH-II

1. Adjust stop lamp switch installation. Refer to BR-18, "Removal and Installation".
2. Check harness continuity between stop lamp switch terminals under the following conditions.