Engine Controls

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.





System Description for the ASCD function.




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 P1564 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605. P0605.









DTC Confirmation Procedure
1. If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next step.
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.
3. Wait at least 10 seconds.
4. Press MAIN switch for at least 10 seconds, then release it and wait at least 10 seconds.
5. Press CANCEL switch for at least 10 seconds, then release it and wait at least 10 seconds.
6. Press RESUME/ACCELERATE switch for at least 10 seconds, then release it and wait at least 10 seconds.
7. Press SET/COAST switch for at least 10 seconds, then release it and wait at least 10 seconds.
8. Check DTC.
9. If DTC is detected, go to Engine Controls.




Diagnosis Procedure
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
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 combination switch harness connector M102.
3. Disconnect ECM harness connector.
4. Check harness continuity between combination switch terminal
15 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 M31, E152
- Harness connectors E5, F14
- 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 14. 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.
- Harness connectors M31, E152
- 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
Engine Controls.
OK or NG
OK - GO TO 8.
NG - Replace ASCD steering switch.
8.CHECK INTERMITTENT INCIDENT
How to Check Terminal and Intermittent Incident.
- INSPECTION END




Component Inspection

ASCD STEERING SWITCH
1. Disconnect combination switch (spiral cable) harness connector M102.





2. Check continuity between combination switch (spiral cable) terminals 14 and 15 with pushing each switch.