Hydraulic Unit (HU) Check: Notes
- Raise the vehicle using a jack and support the specified points with a rigid rack.CAUTION: Before connecting or disconnecting the scan tool (M.U.T.-IIISE), turn off the power supply mode of the electric motor switch.
- Before setting scan tool (M.U.T.-IIISE), turn off the power supply mode of the electric motor switch.
- Confirm that the selector lever is in the "N" position, and then start the engine.
- When carrying out the actuator tests No. 01 to 04, perform the actuator tests using scan tool (M.U.T.-IIISE) while depressing the brake pedal. When carrying out the actuator tests No. 05 to 08, perform the actuator tests using scan tool (M.U.T.-IIISE) without depressing the brake pedal. When carrying out the actuator tests, rotate the wheel by hands to confirm that the braking force changes.NOTE:
- While performing the actuator test, the ABS warning light flashes at a rate of 2 Hz.
- When ASC-ECU is disabled due to the fail-safe function, the scan tool (M.U.T.-IIISE) actuator test cannot be performed.
- After the actuator test has been performed, the ABS warning light, brake waning light, ASC ON indicator light, and ASC OFF indicator light illuminate until the electric motor switch is turned to ON again or the communication between scan tool (M.U.T.-IIISE) and ASC-ECU is terminated.
- This is indicated as shown in the illustration above.
- When any malfunction has been found, take a necessary action according to the "Judgment Table."JUDGMENT DESCRIPTION
Display on scan tool (M.U.T.-IIISE) Operation Test result Judgment Cause Measure 01 FL wheel ABS
02 FR wheel ABS
03 RL wheel ABS
04 RR wheel ABS- Depress the brake pedal to lock the wheel.
- Select the vehicle to be inspected using scan tool (M.U.T.-IIISE), perform the actuator test.
- Rotate the selected wheel by hands to confirm the braking force.
Braking force decreases for 3 seconds from the lock status. Normal - - The wheel does not lock even if the brake pedal is depressed. Error Clogged brake line other than hydraulic unit Check and clean the brake line. Clogged hydraulic circuit in the hydraulic unit Replace the hydraulic unit assembly. Braking force does not decrease. Faulty routing of hydraulic unit brake tube Route the brake tube correctly. Malfunction of hydraulic unit solenoid valve operation Replace the hydraulic unit assembly. 05 FL wheel TCL
06 FR wheel TCL
07 RL wheel TCL
08 RR wheel TCL- Select the vehicle to be inspected using scan tool (M.U.T.-IIISE), perform the actuator test.
- Rotate the selected wheel by hands to confirm the braking force.
Lock condition occurs for 3 seconds from the status without braking force. Normal - - The wheel does not lock. Error - Faulty routing of hydraulic unit brake tube
- Clogged brake line other than hydraulic unit
Check and clean the brake line. Clogged hydraulic circuit in the hydraulic unit Replace the hydraulic unit assembly. - After the inspection, turn off the power supply mode of the electric motor switch, and then disconnect scan tool (M.U.T.-IIISE).