Hydraulic Unit (HU) Check

Required Special Tools: 

• MB992744: Vehicle communication interface-Lite (V.C.I.-Lite)
• MB992745: V.C.I.-Lite main harness A
• MB992747: V.C.I.-Lite USB cable short
• MB992748: V.C.I.-Lite USB cable long
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicles Communication Interface (V.C.I.)
  • MB991827: M.U.T.-III USB Cable
  • MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)

1. Raise the vehicle using a jack and support the specified points with a rigid rack.
   CAUTION: Before connecting or disconnecting scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position.
2. Before setting scan tool (M.U.T.-III), turn the ignition key to the "LOCK" (OFF) position.
3. Confirm that the gearshift lever neutral position <M/T> or the selector lever is in the "N" position <CVT>, and then start the engine.
4. When carrying out the actuator tests item 01 to 04, perform the actuator tests using scan tool (M.U.T.-III) while depressing the brake pedal. When carrying out the actuator tests item 05 to 08, perform the actuator tests using scan tool (M.U.T.-III) without depressing the brake pedal. When carrying out the actuator tests, rotate the wheel by hands to confirm that the braking force changes.
   NOTE:

   • When ASC-ECU is disabled due to the fail-safe function, the scan tool (M.U.T.-III) actuator test cannot be performed.
   • After the actuator test has been performed, the ABS warning light, brake waning light, ASC indicator light and ASC OFF indicator light illuminate until the ignition switch is turned to the "ON" position again or the communication between scan tool (M.U.T.-III) and ASC-ECU is terminated.
   Fig 1: Hydraulic Unit Operation Pattern Graph

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
5. This is indicated as shown in the above.
6. When any malfunction has been found, take a necessary action according to the "Judgment Table."
   JUDGMENT SPECIFICATION
   
   

   Display on scan tool (M.U.T.-III)	Operation	Test result	Judgment	Cause	Measure
   01 FL wheel ABS drive 02 FR wheel ABS drive 03 RL wheel ABS drive 04 RR wheel ABS drive	Depress the brake pedal to lock the wheel. Select the vehicle to be inspected using scan tool (M.U.T.-III), 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 drive 06 FR wheel TCL drive 07 RL wheel TCL drive 08 RR wheel TCL drive	Select the vehicle to be inspected using scan tool (M.U.T.-III), 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.

7. After the inspection, turn the ignition switch to the "LOCK" (OFF) position, and then disconnect scan tool (M.U.T.-III).

Hydraulic unit installation adjustment 

Refer to HYDRAULIC UNIT .

1. Operate the pre-removal steps for the hydraulic unit.
2. Remove all brake tubes.
3. Loosen the mounting bolt and nut of the hydraulic unit bracket.
4. Install all brake tubes temporarily.
5. Shake hydraulic unit to all directions with both hands to make the hydraulic unit bracket insulator fit with the unit.
6. Install the hydraulic unit bracket with mounting bolt and nut not to load the brake tube.
7. Install all brake tubes securely.
   NOTE: Install the flare nut taking care not to let the brake tube turn together.
8. Operate the post-installation steps of the hydraulic unit.