P1572
P1572 ASCD Brake Switch
Component 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 [ASCD: System Description] ASCD System Description for the ASCD function.
On Board Diagnosis Logic
This self-diagnosis has the one trip detection logic.
The MIL will not illuminate for this diagnosis.
NOTE:
- If DTC P 1572 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605. Refer to [Brake Pedal: Exploded View] 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 is turn 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:
- The procedure for malfunction B is not described. It takes an extremely long time to complete the procedure for malfunction B. By performing the procedure for malfunction A, the condition that causes malfunction B can be detected.
- If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next step.
1 Turn ignition switch OFF and wait at least 10 seconds.
2 Turn ignition switch ON.
3 Turn ignition switch OFF and wait at least 10 seconds.
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 SDT
1) Start engine (VDC switch OFF).
2) Select "Data list" mode with SDT.
3) Press MAIN switch and make sure that CRUISE indicator illuminates.
4) Drive the vehicle for at least 5 consecutive seconds under the following condition.
5) Check 1st trip DTC.
If DTC is detected, go to "Diagnosis Procedure".
If DTC is not detected, go to the following step.
6) Drive the vehicle for at least 5 consecutive seconds under the following condition.
7) Check 1st trip DTC.
8) If DTC is detected, go to "Diagnosis Procedure".
with GST
Follow the procedure "WITH SDT" above.
Diagnosis Procedure
A/T Models
1. CHECK OVERALL FUNCTION-I
With SDT
1 Turn ignition switch ON.
2 Select "BRAKE SW1" in "Data list" mode with SDT.
3 Check "BRAKE SW1" indication under the following conditions.
Without SDT
1 Turn ignition switch ON.
2 Check voltage between ECM terminal 108 and ground under the following conditions.
OK or NG
OK
GO TO 2.
NG
GO TO 3.
2. CHECK OVERALL FUNCTION-II
With SDT
Check "BRAKE SW2" indication in "Data list" mode.
Without SDT
Check voltage between ECM terminal 101 and ground under the following conditions.
OK or NG
OK
GO TO 11.
NG
GO TO 7.
3. CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT
1 Turn ignition switch OFF.
2 Disconnect ASCD brake switch (1) harness connector.
- Stop lamp switch (2)
1 Turn ignition switch ON.
2 Check voltage between ASCD brake switch terminal 1 and ground with SDT or tester.
OK or NG
OK
GO TO 5.
NG
GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
- Fuse block (J/B) connector F160
- 10 A fuse
- Harness for open or short between ASCD brake switch and fuse
Repair open circuit or short to ground in harness or connectors.
5. CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1 Turn ignition switch OFF.
2 Disconnect ECM harness connector.
3 Check harness continuity between ECM terminal 108 and ASCD brake switch terminal 2.
Refer to Wiring Diagram.
4 Also check harness for short to ground and short to power.
OK or NG
OK
GO TO 6.
NG
Repair open circuit or short to ground or short to power in harness or connectors.
6. CHECK ASCD BRAKE SWITCH
Refer to "Component Inspection".
OK or NG
OK
GO TO 11.
NG
Replace ASCD brake switch. Refer to Brake Pedal Exploded View.
7. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
1 Turn ignition switch OFF.
2 Disconnect stop lamp switch (2) harness connector.
- ASCD brake switch (1)
1 Check voltage between stop lamp switch terminal 1 and ground with SDT or tester.
OK or NG
OK
GO TO 9.
NG
GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.
- Fuse block (J/B) connector F160
- 10 A fuse (No.20)
- Harness for open or short between stop lamp switch and battery
Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1 Disconnect ECM harness connector.
2 Check harness continuity between ECM terminal 101 and stop lamp switch terminal 2.
Refer to Wiring Diagram.
3 Also check harness for short to ground and short to power.
OK or NG
OK
GO TO 10.
NG
Repair open circuit or short to ground or short to power in harness or connectors.
10. CHECK STOP LAMP SWITCH
Refer to "Component Inspection".
OK or NG
OK
GO TO 11.
NG
Replace stop lamp switch. Refer to [Brake Pedal: Exploded View] Brake Pedal Exploded View.
11. CHECK INTERMITTENT INCIDENT
Refer to [Service Information for Electrical Incident: Intermittent Incident] Service Information for Electrical Incident: Intermittent Incident.
INSPECTION END
M/T Models
1. CHECK OVERALL FUNCTION-I
With SDT
1 Turn ignition switch ON.
2 Select "BRAKE SW1" in "Data list" mode with SDT.
3 Check "BRAKE SW1" indication under the following conditions.
Without SDT
1 Turn ignition switch ON.
2 Check voltage between ECM terminal 108 and ground under the following conditions.
OK or NG
OK
GO TO 2.
NG
GO TO 3.
2. CHECK OVERALL FUNCTION-II
With SDT
Check "BRAKE SW2" indication in "Data list" mode.
Without SDT
Check voltage between ECM terminal 101 and ground under the following conditions.
OK or NG
OK
GO TO 14.
NG
GO TO 10.
3. CHECK ASCD CLUTCH SWITCH POWER SUPPLY CIRCUIT
1 Turn ignition switch OFF.
2 Disconnect ASCD clutch switch harness connector.
3 Turn ignition switch ON.
4 Check voltage between ASCD clutch switch terminal 1 and ground under the following conditions with SDT or tester.
OK or NG
OK
GO TO 8.
NG
GO TO 4.
4. 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 voltage between ASCD brake switch terminal 1 and ground with SDT or tester.
OK or NG
OK
GO TO 6.
NG
GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.
- Fuse block (J/B) connector F160
- 10 A fuse (No.12)
- Harness for open or short between ASCD brake switch and fuse
Repair open circuit or short to ground in harness or connectors.
6. CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1 Turn ignition switch OFF.
2 Check harness continuity between ASCD brake switch terminal 2 and ASCD clutch switch terminal 1.
Refer to Wiring Diagram.
3 Also check harness for short to ground and short to power.
OK or NG
OK
GO TO 7.
NG
Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK ASCD BRAKE SWITCH
Refer to "Component Inspection".
OK or NG
OK
GO TO 14.
NG
Replace ASCD brake switch. Refer to [Brake Pedal: Exploded View] Brake Pedal Exploded View.
8. CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1 Turn ignition switch OFF.
2 Disconnect ECM harness connector.
3 Check harness continuity between ECM terminal 108 and ASCD clutch switch terminal 2.
Refer to Wiring Diagram.
4 Also check harness for short to ground and short to power.
OK or NG
OK
GO TO 9.
NG
Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK ASCD CLUTCH SWITCH
Refer to "Component Inspection".
OK or NG
OK
GO TO 14.
NG
Replace ASCD clutch switch. Refer to [Clutch Pedal: Exploded View] Exploded View.
10. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
1 Turn ignition switch OFF.
2 Disconnect stop lamp switch harness connector.
3 Check voltage between stop lamp switch terminal 2 and ground with SDT or tester.
OK or NG
OK
GO TO 12.
NG
GO TO 11.
11. DETECT MALFUNCTIONING PART
Check the following.
- Fuse block (J/B) connector F160
- 10 A fuse (No.20)
- Harness for open or short between stop lamp switch and battery
Repair open circuit or short to ground or short to power in harness or connectors.
12. CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1 Disconnect ECM harness connector.
2 Check harness continuity between ECM terminal 101 and stop lamp switch terminal 2.
Refer to Wiring Diagram.
3 Also check harness for short to ground and short to power.
OK or NG
OK
GO TO 13.
NG
Repair open circuit or short to ground or short to power in harness or connectors.
13. CHECK STOP LAMP SWITCH
Refer to "Component Inspection".
OK or NG
OK
GO TO 14.
NG
Replace stop lamp switch. Refer to [Brake Pedal: Exploded View] Brake Pedal Exploded View.
14. CHECK INTERMITTENT INCIDENT
Refer to [Service Information for Electrical Incident: Intermittent Incident] Service Information for Electrical Incident: Intermittent Incident.
INSPECTION END
Component Inspection
ASCD Brake Switch
1) Turn ignition switch OFF.
2) Disconnect ASCD brake switch harness connector.
3) Check harness continuity between ASCD brake switch terminals 1 and 2 under the following conditions.
If NG, adjust ASCD brake switch installation, refer to [Brake Pedal: Inspection and Adjustment] Adjustments , and perform step 3 again.
ASCD Clutch Switch
1) Turn ignition switch OFF.
2) Disconnect ASCD clutch switch harness connector.
3) Check harness continuity between ASCD clutch switch terminals 1 and 2 under the following conditions.
If NG, adjust ASCD clutch switch installation, refer to [Clutch Pedal: On-Vehicle Inspection and Adjustment] Testing and Inspection , and perform step 3 again.
Stop Lamp Switch
1) Turn ignition switch OFF.
2) Disconnect stop lamp switch harness connector.
3) Check harness continuity between stop lamp switch terminals 1 and 2 under the following conditions.
If NG, adjust stop lamp switch installation, refer to [Brake Pedal: Inspection and Adjustment] Adjustments , and perform step 3 again.