Code No.P0504: Brake Switch Correction
Code No.P0573: Stop Lamp Switch High














OPERATION



  • As for the stop lamp switch, when the brake pedal is depressed, the stop lamp switch signal is transmitted from the ETACS-ECU to the engine-ECU via CAN bus line.
  • As for the brake switch, when the brake pedal is depressed, battery positive voltage is supplied to the stop lamp switch (terminal No. 3), and when the brake pedal is not depressed, the voltage of engine-ECU (terminal No. 81) will indicate 0 volt.

DIAGNOSIS CODE SET CONDITIONS


Check Condition
  • The cruise control indicator lamp illuminates.
Judgment Criteria
  • Open/short in stop lamp switch circuit.
  • Open circuit in the brake switch circuit (between engine-ECU terminal No. 81 and earth).
  • Malfunction of CAN bus line.

POSSIBLE CAUSES



  • Malfunction of CAN bus system.
  • Damaged harness or connector.
  • Malfunction of the stop lamp switch.
  • Malfunction of the fuse No. 2.
  • Malfunction of the ETACS-ECU.
  • Malfunction of the engine-ECU.

DIAGNOSIS PROCEDURE
caution
  • If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis, diagnose the CAN bus lines.
  • Before replacing the ECU, ensure that the CAN bus lines is normal.

STEP 1. Check the CAN bus system diagnosis.
Using M.U.T.-III, perform CAN bus diagnosis (Refer to GROUP 54C - Explanation About The M.U.T-III Can Bus Diagnostics ).

Q. Is the check result satisfactory?
Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting, Can Bus Diagnostic Table ). Then go to Step 15.

STEP 2. Check the data list.
Using M.U.T.-III, check the data list.

  • Item 74: Stop lamp switch
(Refer to data list reference table ) <BSY>.

Q. Is the check result normal?
Go to Step 9.
Go to Step 3.

STEP 3. Check the ETACS system data list.
Using M.U.T.-III, check the ETACS system data list (Refer to GROUP 54A - ETACS, data list reference table ).

  • Item 290: Brake switch

Q. Is the check result normal?
Replace the engine-ECU (Refer to GROUP 13A - Engine-ECU ). Then go to Step 15.
Go to Step 4.

STEP 4. Connectors check: C-126 stop lamp switch connector, C-304 and C-312 ETACS-ECU connectors.

Q. Is the check result normal?
Go to Step 5.
Repair or replace the damaged components. Then go to Step 15.

STEP 5. Check the harness between ETACS-ECU connector C-304 terminal No. 1 and stop lamp switch connector C-126 terminal No. 2, and check the harness between stop lamp switch connector C-126 terminal No. 1 and ETACS-ECU connector C-312 terminal No. 16.

Q. Is the check result normal?
Go to Step 6.
Repair the damaged harness wire. Then go to Step 15.

STEP 6. Check the stop lamp switch.
(1)Remove the stop lamp switch (Refer to GROUP 35A - Brake Pedal ).
(2)Connect an ohmmeter to the stop lamp switch between terminals No. 1 and No. 2.

(3)Check for continuity between the terminals when the plunger of the stop lamp switch is pushed in and when it is released.
OK: The stop lamp switch is operating properly if the circuit is open between terminals No. 1 and No. 2 when the plunger is pushed in to a depth of within approximately 4.0 mm from the outer case edge surface, and if the resistance value is less than 2 ohms between terminals No. 1 and No. 2 when it is released.

Q. Is the check result normal?

Install the stop lamp switch (Refer to GROUP 35A - Brake Pedal ). Then go to Step 7.

Replace the stop lamp switch (Refer to GROUP 35A - Brake Pedal ). Then go to Step 15.

STEP 7. Check the fuse No. 2 at the ETACS-ECU.

Q. Is the fuse in good condition?
Go to Step 8.
Check the stop lamp system harness and replace the fuse. Then go to Step 15.

STEP 8. Check the ETACS system data list.
Using M.U.T.-III, check the ETACS system data list (Refer to GROUP 54A - ETACS, data list reference table ).

  • Item 290: Brake switch

Q. Is the check result normal?
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 ).
Replace the ETACS-ECU (Refer to GROUP 54A - ETACS, ETACS-ECU ). Then go to Step 15.

STEP 9. Check the data list.
Using M.U.T.-III, check the data list .

  • Item 89: Brake switch
(Refer to data list reference table ) <BSY>.

Q. Is the check result normal?
Go to Step 14.
Go to Step 10.

STEP 10. Connectors check: B-06 engine-ECU connector and C-126 stop lamp switch connector.

Q. Is the check result normal?
Go to Step 11.
Repair or replace the damaged connectors. Then go to Step 15.

STEP 11. Check the harness between engine-ECU connector B-06 terminal No. 81 and stop lamp switch connector C-126 terminal No. 3, and check the harness between stop lamp switch connector C-126 terminal No. 4 and earth.

Q. Is the check result normal?
Go to Step 12.
Repair the damaged harness wire. Then go to Step 15.

STEP 12. Check the stop lamp switch.
(1)Remove the stop lamp switch (Refer to GROUP 35A - Brake Pedal ).
(2)Connect an ohmmeter to the stop lamp switch between terminals No. 3 and No. 4.

(3)Check for continuity between the terminals when the plunger of the stop lamp switch is pushed in and when it is released.
OK: The stop lamp switch is operating properly if the circuit is open between terminals No. 3 and No. 4 when the plunger is released, and if resistance value is less than 2 ohms between terminals No. 3 and No. 4 when the plunger is pushed in to a depth of within approximately 4.5 mm from the outer case edge surface.

Q. Is the check result normal?

Install the stop lamp switch (Refer to GROUP 35A - Brake Pedal ). Then go to Step 13.

Replace the stop lamp switch (Refer to GROUP 35A - Brake Pedal ). Then go to Step 15.

STEP 13. Check the data list.
Using M.U.T.-III, check the data list .

  • Item 89: Brake switch
(Refer to data list reference table ) <BSY>.

Q. Is the check result normal?
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 ).
Replace the engine-ECU (Refer to GROUP 13A - Engine-ECU ). Then go to Step 15.

STEP 14. Read the diagnosis code.
Using M.U.T.-III, read the diagnosis code of the cruise control system (Refer to ).

Q. Is diagnosis code P0504 or P0573 set?
Replace the engine-ECU (Refer to GROUP 13A - Engine-ECU ). Then go to Step 15.
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 15. Check the data list.
Using M.U.T.-III, check the data list .

  • Item 74: Stop lamp switch
  • Item 89: Brake switch
(Refer to data list reference table ) <BSY>.

Q. Is the check result normal?
Go to Step 16.
Return to Step 2.

STEP 16. Read the diagnosis code.
Using M.U.T.-III, read the diagnosis code of the cruise control system (Refer to ).

Q. Is diagnosis code P0504 or P0573 set?
Return to Step 1.
The procedure is complete.