Code No.P1564: Abnormal voltage at cruise control switch.












OPERATION




  • When all switches are released: 4.7 - 5.0 volts
  • When the "ON/OFF" switch is pushed: 0 - 0.5 volt
  • When the "CANCEL" switch is pushed: 1.0 - 1.8 volts
  • When the "COAST/SET" switch is pushed: 2.3 - 3.0 volts
  • When the "ACC/RES" switch is pushed: 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 D-301.
(1)Remove the cruise control switch from the steering wheel with the cruise control switch connector connected (Refer to .)
(2)Connect the negative battery cable 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 D-301 terminal No.4 and earth with cruise control switch connector D-301 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 D-215.
(1)Turn the ignition switch to the "ON" position.
(2)Do not operate the cruise control switch.
(3)Measure the terminal voltage between engine-ECU connector D-215 terminal No.139 and earth with engine-ECU connector connected.
OK: 4.7 - 5.0 V

Q. Is the check result normal?
Go to Step 10.
Go to Step 4.

STEP 4. Connector check: D-215 engine-ECU connector.

Q. Is the check result normal?
Go to Step 5.
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 D-215 terminal No.139 and cruise control switch connector D-301 terminal No.4.
(1)Disconnect engine-ECU connector D-215 and measure at the harness connector side.
(2)Measure the continuity between engine-ECU connector D-215 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: D-301 cruise control switch connector, D-302 and D-305 clock spring connectors, and D-229 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 D-215 terminal No.139 and clock spring connector D-305 terminal No.5, and between clock spring connector D-302 terminal No.2 and cruise control switch connector D-301 terminal No.4.

  • 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: D-215 engine-ECU connector, D-301 cruise control switch connector, D-302 and D-305 clock spring connectors, and D-229 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 D-215 terminal No.139 and clock spring connector D-305 terminal No.5, and between clock spring connector D-302 terminal No.2 and cruise control switch connector D-301 terminal No.4.

  • 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 D-301.
(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 D-301 connected, and measure the terminal voltage between cruise control switch connector D-301 terminal No.3 and earth.
OK: 0.5 V or less

Q. Is the check result normal?
Go to Step 20.
Go to Step 15.

STEP 15. Measure the terminal voltage at engine-ECU connector D-215.
(1)Turn the ignition switch to the "ON" position.
(2)Push the "ON/OFF" switch, and measure the terminal voltage between engine-ECU connector D-215 terminal No.154 and earth with engine-ECU connector D-215 connected.
OK: 0.5 V or less

Q. Is the check result normal?
Go to Step 17.
Go to Step 16.

STEP 16.Connector check: D-215 engine-ECU connector.

Q. Is the check result normal?
Go to Step 24.
Repair or replace the damaged connector. Then go to Step 26.

STEP 17. Connectors check: D-301 cruise control switch connector, D-302 and D-305 clock spring connectors, and D-229 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 D-215 terminal No.154 and clock spring connector D-305 terminal No.4, and between clock spring connector D-302 terminal No.3 and cruise control switch connector D-301 terminal No.3.

  • 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 24.
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 20. Connectors check: D-215 engine-ECU connector, D-301 cruise control switch connector, D-302 and D-305 clock spring connectors, and D-229 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 D-215 terminal No.154 and clock spring connector D-305 terminal No.4, and between clock spring connector D-302 terminal No.3 and cruise control switch connector D-301 terminal No.3.

  • 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 13B - 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 13B - 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 ).

Q. Is diagnosis code No.P1564 set?
Return to Step 1.
The procedure is complete.