ICC Brake Switch

P1572 ICC BRAKE SWITCH





Component Description





When the brake pedal is depressed, ICC brake switch is turned OFF and stop lamp switch is turned ON. ECM detects the state of the brake pedal by this input of two kinds (ON/OFF signal). System Diagram System Description for the ICC function.




On Board Diagnosis Logic
- This 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. 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:
- 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.
- If DTC Confirmation Procedure has been previously conducted, always perform the following procedure 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 3 and 6 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.
1. Start engine (VDC switch OFF).
2. Press MAIN switch and make sure that CRUISE lamp lights up.
3. Drive the vehicle for at least 5 consecutive seconds under the following conditions.





4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to ICC Brake Switch.
If 1st trip DTC is not detected, go to the following step.
6. Drive the vehicle for at least 5 consecutive seconds under the following conditions.





7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to ICC Brake Switch.




Diagnosis Procedure
1.CHECK OVERALL FUNCTION-I
With CONSULT-III
1. Turn ignition switch ON.
2. Select "BRAKE SW1" in "DATA MONITOR" mode with CONSULT-III.
3. Check "BRAKE SW1" indication under the following conditions.





Without CONSULT-III
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 CONSULT-III
Check "BRAKE SW2" indication in "DATA MONITOR" mode.





Without CONSULT-III





Check voltage between ECM terminal 101 and ground under the following conditions.





OK or NG
OK - GO TO 15.
NG - GO TO 9.
3.CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.





2. Disconnect ICC brake switch harness connector.
3. Turn ignition switch ON.





4. Check voltage between ICC brake switch terminal 1 and ground with CONSULT-III or tester.

Voltage: Battery voltage

OK or NG
OK - GO TO 7.
NG - GO TO 4.
4.CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.





2. Disconnect ICC brake hold relay.
3. Check harness continuity between ICC brake switch terminal 1 and ICC brake hold relay terminal 3
Refer to Wiring Diagram.

Continuity should exist.

4. Also check harness for short to ground and short to power.
OK or NG
OK - GO TO 5.
NG - Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK ICC BRAKE HOLD RELAY POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.





2. Check the voltage between ICC brake hold relay terminal 4 and ground with CONSULT-III or tester.

Voltage: Battery voltage

OK or NG
OK - GO TO 14.
NG - GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors M31, E152
- Fuse block (J/B) connector M4
- 10 A fuse (No.15)
- Harness for open or short between ICC brake hold relay and fuse
- Repair open circuit or short to ground or short to power in harness or connectors.
7.CHECK ICC BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ICC brake switch terminal 2 and ECM terminal 108, ICC brake switch terminal 2 and ICC unit terminal 29.
Refer Wiring Diagram.

Continuity should exist.

4. Also check harness for short to ground and short to power.
OK or NG
OK - GO TO 8.
NG - Repair open circuit or short to ground or short to power in harness or connectors.
8.CHECK ICC BRAKE SWITCH
ICC Brake Switch.
OK or NG
OK - GO TO 15.
NG - Replace ICC brake switch.
9.CHECK POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.





2. Disconnect stop lamp switch harness connector.





3. Check voltage between stop lamp switch terminal 3 and ground with CONSULT -III or tester.

Voltage: Battery voltage






4. Disconnect ICC brake hold relay.





5. Check voltage between ICC brake hold relay terminal 7 and ground with CONSULT-III or tester.

Voltage: Battery voltage

OK or NG
OK - GO TO 11.
NG - GO TO 10.
10.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors M31, E152
- Fuse block (J/B) connector M60
- 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.
11.CHECK INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 101 and stop lamp switch terminal 4. Refer to Wiring Diagram.

Continuity should exist.

4. Also check harness for short to ground and short to power.
5. Check harness continuity between ECM terminal 101 and ICC hold relay terminal 6. Refer to Wiring Diagram.

Continuity should exist.

6. Also check harness for short to ground and short to power.
7. Disconnect ICC unit harness connector.
8. Check harness continuity between ECM terminal 101 and ICC unit terminal 38. Refer to Wiring Diagram.

Continuity should exist.

9. Also check harness for short to ground and short to power.
OK or NG
OK - GO TO 13.
NG - GO TO 12.
12.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E34, B40
- Harness for open or short between ICC unit and ECM
- Harness for open or short between ECM and ICC brake hold relay
- Harness for open or short between ECM and ICC brake switch
- Repair open circuit or short to ground or short to power in harness or connectors.
13.CHECK STOP LAMP SWITCH
ICC Brake Switch.
OK or NG
OK - GO TO 14.
NG - Replace stop lamp switch.
14.CHECK
ICC BRAKE HOLD RELAY POWER SUPPLY AND GROUND CIRCUIT FOR OPEN AND
SHORT
1. Check harness continuity between ICC brake hold relay terminal 1 and ICC unit terminal 47, ICC brake hold relay terminal 2 and ground. Refer to Wiring Diagram

Continuity should exist.

2. Also check harness for short to ground or short to power in harness or connectors.
OK or NG
OK - GO TO 15.
NG - Repair or replace.
15.CHECK ICC BRAKE HOLD RELAY
ICC Brake Switch.
OK - GO TO 16.
NG - Replace ICC brake hold relay.
16.CHECK INTERMITTENT INCIDENT
How to Check Terminal and Intermittent Incident.
- INSPECTION END




Component Inspection

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





3. Check continuity between ICC brake switch terminals 1 and 2 under the following conditions.





If NG, adjust ICC brake switch installation, Inspection and Adjustment, 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 3 and 4 under the following conditions.





If NG, adjust stop lamp switch installation, Inspection and Adjustment, and perform step 3 again.

ICC BRAKE HOLD RELAY
1. Apply 12V direct current between ICC brake hold relay terminals 1 and 2.





2. Check continuity between relay terminals 3 and 4, 6 and 7 under the following conditions.





3. If NG, replace ICC brake hold relay.