Code No. C1009 Low brake fluid level














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, Trouble code diagnosis ).

OPERATION


ASC-ECU receives the ON signal of the brake fluid level switch in ETACS-ECU via the CAN bus lines. This indicates that the brake fluid level is lower than the specified.

DIAGNOSIS CODE SET CONDITIONS


This diagnosis code is set when the brake fluid level is lower than the specified.

PROBABLE CAUSES



  • Low brake fluid level
  • Brake fluid level switch malfunction
  • Brake pad wear
  • Damaged wiring harness and connectors
  • Malfunction of ETACS-ECU
  • ASC-ECU malfunction

DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III CAN bus diagnosis


Use 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 - Troubleshooting ). On completion, go to Step 2.

STEP 2. Diagnosis code recheck after resetting CAN bus lines


Q. Is the diagnosis code No. C1009 set?

Go to Step 3.
This diagnosis is complete.

STEP 3. Brake fluid level check


Check that the brake fluid level is higher than the lower limit.

Q. Is the check result normal?

Go to Step 4.
Add brake fluid as necessary.

STEP 4. Brake pad check


Check that the brake pad is thicker than the limit (Refer to GROUP 35A - On-vehicle Service ).

Q. Is the check result normal?

Go to Step 5.
Replace the brake pad (Refer to GROUP 35A - On-vehicle Service ).

STEP 5. Voltage measurement at C-312 ETACS-ECU connector


(1)Turn the ignition switch to the ON position.
(2)Measure the voltage between the terminal No. 1 and the body earth.
OK: Approximately battery voltage

Q. Is the check result normal?

Go to Step 7.
Go to Step 6.

STEP 6. Connector check: C-312 ETACS-ECU connector, A-10 brake fluid level switch connector


Q. Is the check result normal?

The short circuit between the C-312 ETACS-ECU connector terminal No. 1 and the A-10 brake fluid level switch connector terminal No. 1 may be present. Repair the wiring harness between the C-312 ETACS-ECU connector terminal No. 1 and the A-10 brake fluid level switch connector terminal No. 1.
Repair the defective connector.

STEP 7. Brake fluid level switch check


Refer to GROUP 35A - On-vehicle Service .

Q. Is the check result normal?

Go to Step 8.
Replace the brake fluid level switch.

STEP 8. Check whether the diagnosis code is reset.



  • Drive the vehicle at 20 km/h or more.

Q. Is the diagnosis code No. 1009 set?

Replace the ASC-ECU.
This diagnosis is complete.