ASCD Steering Switch
DTC P1564 ASCD STEERING SWITCH
Component Description
ASCD steering switch has variant values of electrical resistance for each button. ECM reads voltage variation of switch, and determines which button is operated. Refer to System Description for the ASCD function.
CONSULT-III Reference Value in Data Monitor Mode
Specification data are reference values.
On Board Diagnosis Logic
This self-diagnosis has the one trip detection logic.
The MIL will not illuminate for this diagnosis.
NOTE:
If DTC P1564 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605. Refer to P0605.
On Board Diagnosis Logic:
DTC Confirmation Procedure
1. If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON and wait at least 10 seconds.
3. Press MAIN switch for at least 10 seconds, then release it and wait at least 10 seconds.
4. Press CANCEL switch for at least 10 seconds, then release it and wait at least 10 seconds.
5. Press RESUME/ACCELERATE switch for at least 10 seconds, then release it and wait at least 10 seconds.
6. Press SET/COAST switch for at least 10 seconds, then release it and wait at least 10 seconds.
7. Check DTC.
8. If DTC is detected, go to ASCD Steering Switch.
Wiring Diagram
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Never use ECM ground terminals when measuring input/output voltage. Doing so may result in damage to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnosis Procedure
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body. Refer to Power Supply and Ground Circuit.
OK or NG
OK - GO TO 2.
NG - Repair or replace ground connections.
2.CHECK ASCD STEERING SWITCH CIRCUIT
With CONSULT-III
1. Turn ignition switch ON.
2. Select "MAIN SW", "CANCEL SW", "RESUME/ACC SW" and "SET SW" in "DATA MONITOR" mode with
CONSULT-III.
3. Check each item indication under the following conditions.
Without CONSULT-III
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 99 and ground with pressing each button.
OK or NG
OK - GO TO 8.
NG - GO TO 3.
3.CHECK ASCD STEERING SWITCH GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect combination switch harness connector M303.
4. Check harness continuity between combination switch terminal 18 and ECM terminal 67. Refer to Wiring Diagram.
Continuity should exist.
5. Also check harness for short to ground and short to power.
OK or NG
OK - GO TO 5.
NG - GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors M72, F102
- Combination switch (spiral cable)
- Harness for open and short between ECM and combination switch
Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK ASCD STEERING SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 99 and combination switch terminal 21. Refer to Wiring Diagram.
Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG
OK - GO TO 7.
NG - GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
- Combination switch (spiral cable)
- Harness for open and short between ECM and combination switch
Repair open circuit or short to ground or short to power in harness or connectors.
7.CHECK ASCD STEERING SWITCH
Refer to ASCD Steering Switch.
OK or NG
OK - GO TO 8.
NG - Replace ASCD steering switch.
8.CHECK INTERMITTENT INCIDENT
Refer to Diagnosis Procedure.
INSPECTION END
Component Inspection
ASCD STEERING SWITCH
1. Disconnect combination switch (spiral cable) harness connector M303.
2. Check continuity between combination switch terminals 18 and
21 with pushing each switch.
