Code No.P1571:
Malfunction of the Stop Lamp Switch System.
OPERATION
- For the stop lamp switch, two switches, a stop lamp switch for the stop lamp
illumination and a brake switch exclusively for the cruise control system, are incorporated
to improve the reliability.
- As for the stop lamp switch, when the brake pedal is depressed/released,
the stop lamp switch ON/OFF signal is transmitted from the ETACS-ECU to the engine-ECU
via CAN bus line.
- As for the brake switch, the engine-ECU connector terminal BRK monitor the state
of the brake switch. The brake switch turn ON/OFF when the brake pedal is depressed/released,
and the input signal to the engine-ECU connector terminal BRK changes. According to this change, the
engine-ECU judges the state of the brake switch.
DIAGNOSIS CODE SET CONDITIONS
Check Condition
- The cruise control indicator lamp illuminates.
Judgement Criteria
- Open/short in stop lamp switch circuit.
- Open circuit in the brake switch circuit (between engine-ECU connector terminal
BRK and earth).
- Malfunction of CAN bus line.
PROBABLE CAUSES
- Malfunction of CAN bus system.
- Damaged harness or connector.
- Malfunction of the fuse.
- Malfunction of the stop lamp switch.
- Malfunction of the ETACS-ECU.
- Malfunction of the engine-ECU.
|
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 11.
|
|
|
|
STEP 2. Check the data list.
|
|
Using M.U.T.-III, check the data list (Refer to data list reference table ).
|
|
- Item 74: Stop lamp switch
|
|
Q.
Is the check result normal?
|
|
Go to Step 6.
|
|
|
|
Go to Step 3.
|
|
|
|
STEP 3. Check the stop lamp operation.
|
|
Check the stop lamp operation.
|
|
OK:
Brake pedal depressed: Stop lamp will illuminate Brake pedal not depressed: Stop lamp does not illuminate
|
|
Q.
Is the check result normal?
|
|
Go to Step 4.
|
|
|
|
Check the stop lamp system (Refer to GROUP 54A - Rear Combination Lamp,
Symptom Procedures, Inspection Procedure 2: The stop lamps do not illuminate or go out normally.
Then go to Step 11.
|
|
|
|
STEP 4. Check the ETACS system data list.
|
|
Using M.U.T.-III, check the ETACS system data list (Refer to GROUP 54A - ETACS,
Troubleshooting, data list reference table).
|
|
- Item 290: Stop lamp switch
|
|
Q.
Is the check result normal?
|
|
Go to Step 5.
|
|
|
|
Replace the ETACS-ECU (Refer to GROUP 54A - ETACS, ETACS-ECU). Then go
to Step 11.
|
|
|
|
STEP 5. Check the data list.
|
|
Using M.U.T.-III, check the data list (Refer to data list reference table ).
|
|
- Item 74: Stop lamp switch
|
|
Q.
Is the check result normal?
|
|
Go to Step 6.
|
|
|
|
Replace the engine-ECU (Refer to GROUP 13A - Engine-ECU). Then go to
Step 11.
|
|
|
|
STEP 6. Check the data list.
|
|
Using M.U.T.-III, check the data list (Refer to data list reference table ).
|
|
Q.
Is the check result normal?
|
|
Go to Step 10.
|
|
|
|
Go to Step 7.
|
|
|
|
STEP 7. Check the harness wire between engine-ECU connector terminal
BRK and stop lamp switch connector terminal, and between stop lamp switch connector terminal
and earth.
|
|
- Check connector or harness wire for open/short circuit and damage.
|
|
Q.
Is the check result normal?
|
|
Go to Step 8.
|
|
|
|
Repair connector or damaged harness wire. Then go to Step 11.
|
|
|
|
STEP 8. Check the stop lamp switch.
|
|
Refer to GROUP 35A - Brake Pedal, Inspection, Stop Lamp Switch Check.
|
|
Q.
Is the check result normal?
|
|
Go to Step 9.
|
|
|
|
Replace the stop lamp switch (Refer to GROUP 35A - Brake Pedal). Then
go to Step 11.
|
|
|
|
STEP 9. Check the data list.
|
|
Using M.U.T.-III, check the data list (Refer to data list reference table ).
|
|
Q.
Is the check result normal?
|
|
Go to Step 10.
|
|
|
|
Replace the engine-ECU (Refer to GROUP 13A - Engine-ECU). Then go to
Step 11.
|
|
|
|
STEP 10. Read the diagnosis code.
|
|
(1)Use the M.U.T.-III, erase the diagnosis code of the cruise control system.
|
|
(2)Turn the ignition switch to the "ON" position, and press the cruise control ON/OFF
switch to turn the cruise control system to ON (the cruise control indicator lamp is turned on).
|
|
(3)With the cruise control switches not operated, depress the brake pedal for several
seconds, and then read the diagnosis code of the cruise control system.
|
|
Q.
Is diagnosis code No.P1571 set?
|
|
Replace the engine-ECU (Refer to GROUP 13A - Engine-ECU). Then go to
Step 11.
|
|
|
|
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 11. Check the data list.
|
|
Using M.U.T.-III, check the data list (Refer to data list reference table ).
|
|
- Item 74: Stop lamp switch
- Item 89: Brake switch
|
|
Q.
Is the check result normal?
|
|
Go to Step 12.
|
|
|
|
Return to Step 2.
|
|
|
|
STEP 12. Read the diagnosis code.
|
|
(1)Use the M.U.T.-III, erase the diagnosis code of the cruise control system.
|
|
(2)Turn the ignition switch to the "ON" position, and press the cruise control ON/OFF
switch to turn the cruise control system to ON (the cruise control indicator lamp is turned on).
|
|
(3)With the cruise control switches not operated, depress the brake pedal for several
seconds, and then read the diagnosis code of the cruise control system.
|
|
Q.
Is diagnosis code No.P1571 set?
|
|
Return to Step 1.
|
|
|
|
The procedure is complete.
|
|
|