Code No.C1340:
Abnormal stop lamp switch circuit
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- 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 (Refer to GROUP 54C - CAN Bus Diagnostics Table
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- Whenever ECU is replaced, ensure that the CAN bus lines are normal.
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OPERATION
- ABS-ECU monitors whether the stop lamp switch is "ON" or "OFF."
DIAGNOSIS CODE SET CONDITIONS
When the vehicle has been driving at a vehicle speed of 15 km/h or more for 15
minutes or longer with the stop lamp switch turned "ON".
PROBABLE CAUSES
Current trouble
- Malfunction of the stop lamp switch
- Damaged wiring harness or connector
- Malfunction of the ETACS-ECU
- Malfunction of the hydraulic unit assembly (integrated with ABS-ECU)
Past trouble
- For diagnosis procedures, refer to How to treat past trouble (GROUP
00 - How to Use Troubleshooting/Inspection Service Points ).
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STEP 1. M.U.T.-III CAN bus diagnosis
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Use the M.U.T.-III to diagnose the CAN bus lines.
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Q.
Is the check result normal?
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 Go to Step 3.
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 Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
On completion, go to Step 2.
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STEP 2. Diagnosis code recheck after resetting CAN bus lines
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(1)Turn the ignition switch to the "LOCK" (OFF) position.
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(2)Turn the ignition switch to the "ON" position.
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(3)Erase the diagnosis code.
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(4)Turn the ignition switch to the "LOCK" (OFF) position.
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(5)Turn the ignition switch to the "ON" position.
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(6)Check if the diagnosis code is set.
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Q.
Is diagnosis code No. C1340 set?
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Go to Step 3.
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This diagnosis is complete.
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STEP 3. Check the stop lamp operation
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Check the stop lamp operation when the brake pedal is depressed. Check that the stop lamp
and high-mount stop lamp illuminates when the brake pedal is depressed and that it goes out
when the brake pedal is released.
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OK:
When the brake pedal is released: Not illuminate
When the brake pedal is depressed: Illuminate
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Q.
Is the check result normal?
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Go to Step 6.
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Go to Step 4.
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STEP 4. Check for stop lamp switch installation
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Check the stop lamp switch installation (Refer to GROUP 35A - On-vehicle Service,
Brake Pedal Check and Adjustment ).
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Q.
Is the check result normal?
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Go to Step 5.
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Install the stop lamp switch correctly (Refer to GROUP 35A - On-vehicle
Service, Brake Pedal Check and Adjustment ). Then go to
Step 9.
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STEP 5. Stop lamp switch continuity check
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(1)Check the stop lamp switch connector.
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(2)Refer to GROUP 35A - Inspection, Stop Lamp Switch Check .
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Q.
Is the check result normal?
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Go to Step 6.
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Replace the stop lamp switch (Refer to GROUP 35A - Brake Pedal ).
Then go to Step 9.
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STEP 6. Measure the voltage at the ETACS-ECU connector
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(1)Disconnect the connector.
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(2)Depress the brake pedal.
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(3)Measure the voltage between the terminal BKLP and earth.
OK: Approximately system voltage
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Q.
Is the check result normal?
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Go to Step 7.
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Repair the defective connector or the wiring harness. Then go to Step 9.
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STEP 7. M.U.T.-III other system data list
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- Check the data lists of the ETACS-ECU (Refer to GROUP 54A - Troubleshooting - Data
List Reference Table ).
- Item 108: Stop lamp switch
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OK: ON (Depress the brake pedal), OFF (Release the brake pedal)
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Q.
Is the check result normal?
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Go to Step 8.
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Replace the ETACS-ECU (Refer to GROUP 54A - ETACS-ECU ). Then
go to Step 9.
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STEP 8. Check whether the diagnosis code is set again.
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(1)Turn the ignition switch to the "LOCK" (OFF) position.
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(2)Turn the ignition switch to the "ON" position.
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(3)Erase the diagnosis code.
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(4)Turn the ignition switch to the "LOCK" (OFF) position.
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(5)Turn the ignition switch to the "ON" position.
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(6)Drive the vehicle at 15 km/h or more for 15 minutes.
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(7)Check if the diagnosis code is set.
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Q.
Is diagnosis code No. C1340 set?
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Replace the hydraulic unit assembly (integrated with ABS-ECU) (Refer to ). Then
go to Step 9.
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The trouble can be an intermittent malfunction (Refer to GROUP 00 - How
to Cope with Intermittent Malfunction ).
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STEP 9. Check whether the diagnosis code is set again.
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(1)Turn the ignition switch to the "LOCK" (OFF) position.
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(2)Turn the ignition switch to the "ON" position.
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(3)Erase the diagnosis code.
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(4)Turn the ignition switch to the "LOCK" (OFF) position.
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(5)Turn the ignition switch to the "ON" position.
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(6)Drive the vehicle at 15 km/h or more for 15 minutes.
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(7)Check if the diagnosis code is set.
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Q.
Is diagnosis code No. C1340 set?
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Return to Step 1.
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The procedure is complete.
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