P1572

DTC P1572 ASCD BRAKE SWITCH




Component Description
When the brake pedal is depressed, ASCD brake switch (1) is turned OFF and stop lamp switch (2) is turned ON. ECM detects the state of the brake pedal (3) by this input of two kinds (ON/OFF signal). Refer to "AUTOMATIC SPEED CONTROL DEVICE (ASCD)" for the ASCD function.




CONSULT-III Reference Value in Data Monitor Mode




On Board Diagnosis Logic
- This self-diagnosis has the one trip detection logic.
- The MIL will not light up for this self-diagnosis.

NOTE:
- If DTC P1572 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605. Refer to EC-406, "DTC P0605 ECM". P0605
- This self-diagnosis has the one trip detection logic. When malfunction A is detected, DTC is not stored in ECM memory. And in that case, 1st trip DTC and 1st trip freeze frame data are displayed. 1st trip DTC is erased when ignition switch OFF. And even when malfunction A is detected in two consecutive trips, DTC is not stored in ECM memory.

DTC Confirmation Procedure

CAUTION: Always drive vehicle at a safe speed.

NOTE:
- If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.
- Procedure for malfunction B is not described here. It takes extremely long time to complete procedure for malfunction B. By performing procedure for malfunction A, the incident that causes malfunction B can be detected.

TESTING CONDITION:
Steps 4 and 5 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road test is expected to be easier, it is unnecessary to lift the vehicle.

WITH CONSULT-III
1. Start engine.
2. Select "DATA MONITOR" mode with CONSULT-III.
3. Press MAIN switch and make sure that CRUISE indicator lights up.




4. Drive the vehicle for at least 5 consecutive seconds under the given condition.
5. Check 1st trip DTC.
If 1st trip DTC is detected, go to "Diagnostic Procedure" below.
If 1st trip DTC is not detected, go to the following step.




6. Drive the vehicle for at least 5 consecutive seconds under the given condition.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to "Diagnostic Procedure" below.

WITH GST
Follow the procedure "WITH CONSULT-III".

EC-ASC/BS-01:

Wiring Diagram

Step 1:

Step 2-3:

Step 4-7:

Step 8-10:

Step 11-13:

Step 14-15:

Diagnostic Procedure

Component Inspection

ASCD BRAKE SWITCH
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.




3. Check continuity between ASCD brake switch terminals 1 and 2 under the given conditions.
If NG, adjust ASCD brake switch installation, refer to "BRAKE PEDAL", and perform step 3 again.

ASCD CLUTCH SWITCH
1. Turn ignition switch OFF.
2. Disconnect ASCD clutch switch harness connector.




3. Check continuity between ASCD clutch switch terminals 1 and 2 under the given conditions.
If NG, adjust ASCD clutch switch installation, refer to "CLUTCH PEDAL", and perform step 3 again.

STOP LAMP SWITCH
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.




3. Check continuity between stop lamp switch terminals 1 and 2 under the given conditions.
If NG, adjust stop lamp switch installation, refer to "BRAKE PEDAL", and perform step 3 again.