Code No.C1361:
Abnormal master cylinder pressure sensor characteristics
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 (Refer to GROUP 54C - CAN Bus Diagnostics Table
).
- Whenever ECU is replaced, ensure that the CAN bus lines are normal.
- When the hydraulic unit (integrated with ASTC-ECU) is replaced, always carry out
the calibration of the steering wheel sensor and the G and yaw rate sensor (Refer to
).
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OPERATION
ASTC-ECU incorporates the master cylinder pressure sensor, and monitors the brake fluid pressure.
DIAGNOSIS CODE SET CONDITIONS
- The pressure sensor output signal is not changed after the vehicle speed
exceeds 7 km/h.
- The pressure sensor output signal fluctuates only within a predetermined value while
the vehicle is decelerated from 40 km/h to a standstill.
- Pressure sensor output signal fails
PROBABLE CAUSES
- The CAN bus line is defective.
- Incorrect adjustment of the stop lamp switch
- Malfunction of the stop lamp switch
- Malfunction of the ETACS-ECU
- Damaged wiring harness or connector
- Malfunction of the hydraulic unit assembly (integrated with ASTC-ECU)
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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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Check again if the diagnosis code is set.
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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. U1109 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
8 .
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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 8.
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STEP 6. Measure the voltage at ETACS-ECU connector.
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(1)Disconnect the connector and measure at the wiring harness side.
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(2)Turn the ignition switch to the "ON" position.
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(3)Measure the voltage between ETACS-ECU BKLP terminal and body earth. OK:
When the brake pedal is released: 1V or less When the brake pedal is depressed: System voltage
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Q.
Is the check result normal?
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Go to Step 7.
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An open or short circuit to power supply has occurred in the wiring harness between
ETACS-ECU connector and stop lamp switch connector. Repair the relevant fault. Then go to Step
8.
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STEP 7. Check whether the diagnosis code is set again.
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Check again if the diagnosis code is set.
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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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(7)Turn the ignition switch to the "LOCK" (OFF) position.
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Q.
Is diagnosis code No. C1361 set?
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Replace the hydraulic unit assembly (integrated with ASTC-ECU). (Refer to .)
Then go to Step 8.
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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 8. Check whether the diagnosis code is set again.
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Check again if the diagnosis code is set.
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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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(7)Turn the ignition switch to the "LOCK" (OFF) position.
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Q.
Is diagnosis code No. C1361 set?
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Return to Step 1.
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The procedure is complete.
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