P1572-904

P1572-904





Description
When the brake pedal is depressed, ASCD brake switch is turned OFF and stop lamp switch is turned ON.
The hybrid vehicle control ECU detects the state of the brake pedal by this input of two kinds (ON/OFF signal). Refer to System Description for the ASCD function.




DTC Logic

DTC DETECTION LOGIC









Component Function Check
1.CHECK FOR ASCD BRAKE SWITCH FUNCTION
With CONSULT-III
1. Turn ignition switch ON.
2. Select "ASCD CANSEL SW" in "DATA MONITOR" mode with CONSULT-III.
3. Check "ASCD CANSEL SW" indication under the following conditions.






With GST
1. Turn ignition switch ON.
2. Check the voltage between hybrid vehicle control ECU harness connector and ground.






Is the inspection result normal?
YES - INSPECTION END
NO - Go to "Diagnosis Procedure".




Diagnosis Procedure
1.PRECONDITIONING
- Before inspecting the high-voltage system or disconnecting the low voltage connector of the inverter with converter assembly, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
- After disconnecting the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals.
- Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.
- GO TO 2.
2.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.






Is the inspection result normal?
YES - GO TO 4.
NO - GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
- Fuse block (J/B) connector E6
- Junction block connector E46, E48
- 10A fuse (No.3)
- Harness for open or short between ASCD brake switch and fuse
- Repair open circuit or short to power in harness or connectors.
4.CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect hybrid vehicle control ECU harness connector.
3. Check the continuity between ASCD brake switch harness connector and hybrid vehicle control ECU harness connector.






4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES - GO TO 6.
NO - GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
- Junction block connector E46, E50
- Harness for open or short between ASCD brake switch and hybrid vehicle control ECU
- Repair open circuit or short to power in harness or connectors.
6.CHECK ASCD BRAKE SWITCH
Refer to "Component Inspection (ASCD Brake Switch)".
Is the inspection result normal?
YES - GO TO 7.
NO - Replace ASCD brake switch.
7.CHECK INTERMITTENT INCIDENT
Refer to Intermittent Incident.
- INSPECTION END




Component Inspection (ASCD Brake Switch)
1.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.






Is the inspection result normal?
YES - INSPECTION END
NO - GO TO 2.
2.CHECK ASCD BRAKE SWITCH-II
1. Adjust ASCD brake switch installation. Refer to Procedures.






2. Check the continuity between ASCD brake switch terminals under the following conditions.






Is the inspection result normal?
YES - INSPECTION END
NO - Replace ASCD brake switch.