Code No.P1564:
Abnormal voltage at cruise control switch
OPERATION
This circuit judges the signals of each switch ("ON/OFF", "CANCEL", "COAST/SET"
and "ACC/RES") of the cruise control switch. The engine-ECU detects the state of the
cruise control switch by sensing the voltages shown below.
When all switches are released: 4.7 - 5.0 volts
When the "ON/OFF" switch is pressed: 0 - 0.5 volt
When the "CANCEL" switch is pressed: 1.0 - 1.8 volts
When the "COAST/SET" switch is pressed: 2.3 - 3.0 volts
When the "ACC/RES" switch is pressed: 3.5 - 4.2 volts
DIAGNOSIS CODE SET CONDITIONS
If the cruise control switch is operated, this diagnosis
code will be set when the engine-ECU terminal voltage is different from the standard value.
Or, this code is set when the "COAST/SET" switch or "ACC/RES"
switch is stuck to ON.
PROBABLE CAUSES
Damaged harness or connector.
Malfunction of the cruise control switch.
Malfunction of the clock spring.
Malfunction of the engine-ECU.
DIAGNOSIS PROCEDURE
STEP 1. Check the data list.
Using M.U.T.-III, check the data list (Refer to - data
list reference table).
Item 136: "ON/OFF" switch
Item 137: "CANCEL" switch
Item 138: "COAST/SET" switch
Item 139: "ACC/RES" switch
Q.
Is the check result normal?
Go to Step 25.
Go to Step 2.
STEP 2. Measure the terminal voltage at cruise control switch connector
C-309.
(1)Remove the cruise control switch from the steering wheel with the cruise control
switch connector connected (Refer to ).
(2)Connect the negative battery terminal that was disconnected when the driver’s
air bag module was removed.
(3)Turn the ignition switch to the "ON" position.
(4)Do not operate the cruise control switch.
(5)Measure the terminal voltage between cruise control switch connector C-309 terminal
No.3 and earth with cruise control switch connector C-309 connected. OK: 4.7 - 5.0 V
Q.
Is the check result normal?
Go to Step 14.
Go to Step 3.
STEP 3. Measure the terminal voltage at engine-ECU connector C-103.
(1)Remove the engine-ECU (Refer to GROUP 13A - Engine-ECU ).
(2)Connect special tool power plant ECU check harness (MB992291) between the engine-ECU
and the body-side harness connector.
(3)Turn the ignition switch to the "ON" position.
(4)Do not operate the cruise control switch.
(5)Measure the terminal voltage between special tool 58-pin connector terminal No.139
(engine-ECU connector C-103 terminal No.139) and earth. OK: 4.7 - 5.0 V
Repair or replace the damaged connector. Then go to Step 26.
STEP 5. Check the harness wire for short circuit to earth between
engine-ECU connector C-103 terminal No.139 and cruise control switch connector C-309 terminal
No.3.
(1)Disconnect engine-ECU connector C-103 and measure at the harness connector side
(Refer to GROUP 13A - Engine-ECU ).
(2)Turn the ignition switch to the "LOCK" (OFF) position.
(3)Measure the continuity between engine-ECU connector C-103 terminal No.139 and earth. OK: open circuit
Q.
Is the check result normal?
Go to Step 24 .
Go to Step 6.
STEP 6. Connectors check: C-309 cruise control switch connector, C-306
and C-310 clock spring connectors and C-53 <LHD> or C-35 <RHD> intermediate connector.
Q.
Is the check result normal?
Go to Step 7.
Repair or replace the damaged connector. Then go to Step 26.
STEP 7. Check the harness wire between engine-ECU connector C-103
terminal No.139 and clock spring connector C-306 terminal No.5, and between clock spring connector
C-310 terminal No.2 and cruise control switch connector C-309 terminal No.3.
Check harness wire for short circuit and damage.
Q.
Is the check result normal?
Go to Step 8.
Repair or replace the damaged harness wire. Then go to Step 26.
STEP 8. Check the clock spring.
Refer to GROUP 52B - Driver’s, Front Passenger’s Air Bag Module(s)
and Clock Spring Inspection .
Q.
Is the check result normal?
Go to Step 9.
Replace the clock spring [Refer to GROUP 52B - Driver’s,
Front Passenger’s Air Bag Module(s) and Clock Spring ].
Then go to Step 26.
STEP 9. Check the cruise control switch.
Refer to .
Q.
Is the check result normal?
Go to Step 13.
Replace the cruise control switch (Refer to ). Then
go to Step 26.
STEP 10. Connectors check: C-103 engine-ECU connector, C-309 cruise
control switch connector, C-306 and C-310 clock spring connectors and C-53 <LHD> or
C-35 <RHD> intermediate connector.
Q.
Is the check result normal?
Go to Step 11.
Repair or replace the damaged connector. Then go to Step 26.
STEP 11. Check the harness wire between engine-ECU connector C-103
terminal No.139 and clock spring connector C-306 terminal No.5, and between clock spring connector
C-310 terminal No.2 and cruise control switch connector C-309 terminal No.3.
Check harness wire for open circuit and damage.
Q.
Is the check result normal?
Go to Step 12.
Repair or replace the damaged harness wire. Then go to Step 26.
STEP 12. Check the clock spring.
Refer to GROUP 52B - Driver’s, Front Passenger’s Air Bag Module(s)
and Clock Spring Inspection .
Q.
Is the check result normal?
Go to Step 13.
Replace the clock spring [Refer to GROUP 52B - Driver’s,
Front Passenger’s Air Bag Module(s) and Clock Spring ].
Then go to Step 26.
STEP 13. Check the data list.
Using M.U.T.-III, check the data list (Refer to - data
list reference table).
Item 136: "ON/OFF" switch
Item 137: "CANCEL" switch
Item 138: "COAST/SET" switch
Item 139: "ACC/RES" switch
Q.
Is the check result normal?
Go to Step 25.
Go to Step 14.
STEP 14. Measure the terminal voltage at cruise control switch connector
C-309.
(1)Remove the cruise control switch from the steering wheel with the cruise control
switch connector connected (Refer to ).
(2)Connect the negative battery terminal that was disconnected when the driver’s
air bag module was removed.
(3)Turn the ignition switch to the "ON" position.
(4)Push the "ON/OFF" switch with cruise control switch connector C-309 connected,
and measure the terminal voltage between cruise control switch connector C-309 terminal No.2
and earth. OK: 0 - 0.5 V
Q.
Is the check result normal?
Go to Step 20.
Go to Step 15.
STEP 15. Measure the terminal voltage at engine-ECU connector C-103.
(1)Remove the engine-ECU (Refer to GROUP 13A - Engine-ECU ).
(2)Connect special tool power plant ECU check harness (MB992291) between the engine-ECU
and the body-side harness connector.
(3)Turn the ignition switch to the "ON" position.
(4)Push the "ON/OFF" switch, and measure the terminal voltage between special
tool 58-pin connector terminal No.154 (engine-ECU connector C-103 terminal No.154) and earth. OK: 0 - 0.5 V
Repair or replace the damaged connector. Then go to Step 26.
STEP 17. Connectors check: C-309 cruise control switch connector,
C-306 and C-310 clock spring connectors and C-53 <LHD> or C-35 <RHD> intermediate connector.
Q.
Is the check result normal?
Go to Step 18.
Repair or replace the damaged connector. Then go to Step 26.
STEP 18. Check the harness wire between engine-ECU connector C-103
terminal No.154 and clock spring connector C-306 terminal No.4, and between clock spring connector
C-310 terminal No.3 and cruise control switch connector C-309 terminal No.2.
Check harness wire for open circuit and damage.
Q.
Is the check result normal?
Go to Step 19.
Repair or replace the damaged harness wire. Then go to Step 26.
STEP 19. Check the clock spring.
Refer to GROUP 52B - Driver’s, Front Passenger’s Air Bag Module(s)
and Clock Spring Inspection .
Q.
Is the check result normal?
Go to Step 20.
Replace the clock spring and install the driver’s air bag module [Refer
to GROUP 52B - Driver’s, Front Passenger’s Air Bag Module(s) and
Clock Spring ]. Then go to Step 26.
STEP 20. Connectors check: C-103 engine-ECU connector, C-309 cruise
control switch connector, C-306 and C-310 clock spring connectors and C-53 <LHD> or
C-35 <RHD> intermediate connector.
Q.
Is the check result normal?
Go to Step 21.
Repair or replace the damaged connector. Then go to Step 26.
STEP 21. Check the harness wire between engine-ECU connector C-103
terminal No.154 and clock spring connector C-306 terminal No.4, and between clock spring connector
C-310 terminal No.3 and cruise control switch connector C-309 terminal No.2.
Check harness wire for short circuit and damage.
Q.
Is the check result normal?
Go to Step 22.
Repair or replace the damaged harness wire. Then go to Step 26.
STEP 22. Check the clock spring.
Refer to GROUP 52B - Driver’s, Front Passenger’s Air Bag Module(s)
and Clock Spring Inspection .
Q.
Is the check result normal?
Go to Step 23.
Replace the clock spring [Refer to GROUP 52B - Driver’s,
Front Passenger’s Air Bag Module(s) and Clock Spring ].
Then go to Step 26.
STEP 23. Check the cruise control switch.
Refer to .
Q.
Is the check result normal?
Go to Step 24.
Replace the cruise control switch (Refer to ). Then
go to Step 26.
STEP 24. Check the data list.
Using M.U.T.-III, check the data list (Refer to - data
list reference table).
Item 136: "ON/OFF" switch
Item 137: "CANCEL" switch
Item 138: "COAST/SET" switch
Item 139: "ACC/RES" switch
Q.
Is the check result normal?
Go to Step 25.
Replace the engine-ECU (Refer to GROUP 13A - Engine-ECU ).
Then go to Step 26.
STEP 25. Read the diagnosis code.
(1)Use the M.U.T.-III, erase the diagnosis code of the cruise control system (Refer
to ).
(2)Turn the ignition switch to the "ON" position, and push the "ON/OFF" switch
to turn the cruise control system to ON (turn ON the cruise control indicator lamp).
(3)After turning the cruise control system to ON, when 2 minutes or more has elapsed
without operating the cruise control switches, use the M.U.T.-III to read the diagnosis code
of the cruise control system (Refer to ).
Q.
Is diagnosis code No.P1564 set?
Replace the engine-ECU (Refer to GROUP 13A - Engine-ECU ).
Then go to Step 26.
It can be assumed that this malfunction is intermittent (Refer to GROUP 00 - How
to Use Troubleshooting/Inspection Service Points, How to Cope with Intermittent Malfunction ).
STEP 26. Check the data list.
Using M.U.T.-III, check the data list (Refer to - data
list reference table).
Item 136: "ON/OFF" switch
Item 137: "CANCEL" switch
Item 138: "COAST/SET" switch
Item 139: "ACC/RES" switch
Q.
Is the check result normal?
Go to Step 27.
Return to Step 2.
STEP 27. Read the diagnosis code.
(1)Use the M.U.T.-III, erase the diagnosis code of the cruise control system (Refer
to ).
(2)Turn the ignition switch to the "ON" position, and push the "ON/OFF" switch
to turn the cruise control system to ON (turn ON the cruise control indicator lamp).
(3)After turning the cruise control system to ON, when 2 minutes or more has elapsed
without operating the cruise control switches, use the M.U.T.-III to read the diagnosis code
of the cruise control system (Refer to ).
)
)
)
)
)
- data
list reference table).
Go to Step 25.
Go to Step 2.