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 ).
|
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)
|
|
STEP 1. M.U.T.-III CAN bus diagnosis
|
|
|
Use the M.U.T.-III to diagnose the CAN bus lines.
|
|
|
Q.
Is the check result normal?
|
|
|
 Go to Step 3.
|
|
|
|
|
|
 Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
On completion, go to Step 2.
|
|
|
|
|
|
STEP 2. Diagnosis code recheck after resetting CAN bus lines
|
|
|
Check again if the diagnosis code is set.
|
|
|
(1)Turn the ignition switch to the "LOCK" (OFF) position.
|
|
|
(2)Turn the ignition switch to the "ON" position.
|
|
|
(3)Erase the diagnosis code.
|
|
|
(4)Turn the ignition switch to the "LOCK" (OFF) position.
|
|
|
(5)Turn the ignition switch to the "ON" position.
|
|
|
(6)Check if the diagnosis code is set.
|
|
|
Q.
Is diagnosis code No. U1109 set?
|
|
|
Go to Step 3.
|
|
|
|
|
|
This diagnosis is complete.
|
|
|
|
|
|
STEP 3. Check the stop lamp operation
|
|
|
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.
|
|
|
OK:
When the brake pedal is released: Not illuminate
When the brake pedal is depressed: Illuminate
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 6.
|
|
|
|
|
|
Go to Step 4.
|
|
|
|
|
|
STEP 4. Check for stop lamp switch installation
|
|
|
Check the stop lamp switch installation (Refer to GROUP 35A - On-vehicle Service,
Brake Pedal Check and Adjustment ).
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 5.
|
|
|
|
|
|
Install the stop lamp switch correctly (Refer to GROUP 35A - On-vehicle
Service, Brake Pedal Check and Adjustment ). Then go to Step
8 .
|
|
|
|
|
|
STEP 5. Stop lamp switch continuity check
|
|
|
(1)Check the stop lamp switch connector.
|
|
|
(2)Refer to GROUP 35A - Inspection, Stop Lamp Switch Check .
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 6.
|
|
|
|
|
|
Replace the stop lamp switch (Refer to GROUP 35A - Brake Pedal ).
Then go to Step 8.
|
|
|
|
|
|
STEP 6. Measure the voltage at ETACS-ECU connector.
|
|
|
(1)Disconnect the connector and measure at the wiring harness side.
|
|
|
(2)Turn the ignition switch to the "ON" position.
|
|
|
(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
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 7.
|
|
|
|
|
|
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.
|
|
|
|
|
|
STEP 7. Check whether the diagnosis code is set again.
|
|
|
Check again if the diagnosis code is set.
|
|
|
(1)Turn the ignition switch to the "LOCK" (OFF) position.
|
|
|
(2)Turn the ignition switch to the "ON" position.
|
|
|
(3)Erase the diagnosis code.
|
|
|
(4)Turn the ignition switch to the "LOCK" (OFF) position.
|
|
|
(5)Turn the ignition switch to the "ON" position.
|
|
|
(6)Check if the diagnosis code is set.
|
|
|
(7)Turn the ignition switch to the "LOCK" (OFF) position.
|
|
|
Q.
Is diagnosis code No. C1361 set?
|
|
|
Replace the hydraulic unit assembly (integrated with ASTC-ECU). (Refer to .)
Then go to Step 8.
|
|
|
|
|
|
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How
to Cope with Intermittent Malfunction ).
|
|
|
|
|
|
STEP 8. Check whether the diagnosis code is set again.
|
|
|
Check again if the diagnosis code is set.
|
|
|
(1)Turn the ignition switch to the "LOCK" (OFF) position.
|
|
|
(2)Turn the ignition switch to the "ON" position.
|
|
|
(3)Erase the diagnosis code.
|
|
|
(4)Turn the ignition switch to the "LOCK" (OFF) position.
|
|
|
(5)Turn the ignition switch to the "ON" position.
|
|
|
(6)Check if the diagnosis code is set.
|
|
|
(7)Turn the ignition switch to the "LOCK" (OFF) position.
|
|
|
Q.
Is diagnosis code No. C1361 set?
|
|
|
Return to Step 1.
|
|
|
|
|
|
The procedure is complete.
|
|
|
|