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DIAGNOSTIC FUNCTION
Electric parking brake ECU has the following functions for easier system checks.
All the above items can be diagnosed using scan tool (M.U.T.-IIISE).
 
 
CHECK OF FREEZE FRAME DATA
The freeze frame data can be checked by using the scan tool (M.U.T.-IIISE).
 
 
When detecting fault and setting the DTC, the ECU connected to CAN bus line obtains the data before the determination of the DTC and the data when the DTC is determined, and then stores the ECU status of that time. By analysing each data from scan tool (M.U.T.-IIISE), the troubleshooting can be performed more efficiently. The displayed items are as the table below.
Display item list
Item No.Item nameData itemUnit
1OdometerTotal driving distance after the DTC is setkm/mile
2Ignition cycleNumber of times the power supply mode of the electric motor switch is turned ON or OFF after the past failure transitionNumber of counts is displayed.
3Right actuator currentRight actuator current when the DTC is set.A
4Left actuator currentLeft actuator current when the DTC is set.A
5Target currentTarget current when the DTC is set.A
6Control vehicle speedVehicle speed (wheel speed) when the DTC is setr/min
7Power supply voltageVoltage of power supply when the DTC is setV
8Parking brake statusElectric parking brake control when the DTC is set: Release/Lock/Lock -> Release/Release -> Lock/Undefined/EPB dynamic BRK/ASC dynamic BRK-
9EPB switch: LOCK 1 SWElectric parking brake switch (Lock switch 1) condition when the DTC is set: OFF/ON/Open/Short-
10EPB switch: LOCK 2 SWElectric parking brake switch (Lock switch 2) condition when the DTC is set: OFF/ON/Open/Short-
11EPB switch: RELEASE 1 SWElectric parking brake switch (Release switch 1) condition when the DTC is set: OFF/ON/Open/Short-
12EPB switch: RELEASE 2 SWElectric parking brake switch (Release switch 2) condition when the DTC is set: OFF/ON/Open/Short-
13Ignition switch (Hard wire)IG1 signal (hard wire) condition when the DTC is set: OFF/ON-
14Acceleration pedalAccelerator pedal position sensor condition when the DTC is set: OFF/ON-
15Shift informationShift condition when the DTC is set: P/R/N/D-
16Driver's seat beltDriver's seat belt condition when the DTC is set.: Not fastened/Fastened-
17Ignition switch (CAN)IG1 signal (CAN signal) condition when the DTC is set: OFF/ON-
18Run mode (PHEV)Run mode when the DTC is set: OFF/ON-
19Master cylinder pressureMaster cylinder pressure when the DTC is set.MPa/psi
20Longitudinal GLongitudinal gravity when the DTC is set.m/s2
21Engine Torque (except PHEV)Not used.-
22Motor Torque (PHEV)Motor torque condition when the DTC is set.Nm
 
 
FAIL-SAFE FUNCTIONS
When the electric parking brake ECU detects any malfunction in the system, the ECU will activate the brake warning light, the electric parking brake warning light and the electric parking brake switch indicator light to inform the driver that the electric parking brake is disabled.
In addition, the ECU displays a warning notice on the multi-information display in the combination meter.
 
 
Illumination condition of warning light, indicator light and multi information display in case of failure
DTC No.Inspection itemBrake warning lightElectric parking brake warning lightMulti information displayElectric parking brake switch indicator light
C1607ECU failureOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
C1707Implausible coding dataOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
C1861Power supply low voltageFlash (1 Hz)OFF-Flash (1 Hz)
C2253EPB SW malfunctionFlash (1 Hz)*1ONPARKING BRAKE SERVICE REQUIREDFlash (1 Hz)*1
C2254IG SW malfunctionOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
C2300Left actuator malfunctionFlash (1 Hz)ONPARKING BRAKE SERVICE REQUIREDFlash (1 Hz)
C2301Right Actuator malfunctionFlash (1 Hz)ONPARKING BRAKE SERVICE REQUIREDFlash (1 Hz)
C2302Left Motor malfunctionOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
C2303Right Motor malfunctionOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
C2304Left +B voltage malfunctionOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
C2305Right +B voltage malfunctionOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
U0121ABS/ASC CAN timeoutOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
U0141ETACS CAN timeoutOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
U0415ABS/ASC (CAN message)OFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
U1010PHEV ECU Parity/Toggle bit errorOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
U1073Bus-offOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
U110APHEV-ECU CAN timeoutOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
U1195Coding not completedOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
-The power supply voltage is abnormal*2.Flash (1 Hz)OFF-Flash (1 Hz)
-The system detects a continuous operation of the electric parking brake (to protect the electric motor from overheat)*3.Flash (1 Hz)OFFPARKING BRAKE TEMPORARILY NOT AVAILABLEFlash (1 Hz)
-The system detects that the electric parking brake is engaged poorly (the vehicle moves) continuously.Flash (1 Hz)OFF-Flash (1 Hz)
note
  • *1: The light will flash if all of the four apply and release circuits for the electric parking brake switch are open.
  • *2: The power supply voltage is high or excessively low.
  • *3: If you operate the electric parking brake switch repeatedly in a short period of time, a warning screen will be displayed and the electric parking brake may be disabled temporarily. In this case, you have to wait for approx. one minute after the warning screen disappears until the switch can be operated.
  • *4: illuminates according to the status of the electric parking brake.
 
 
Under apply, release and emergency brake*1 in case of failure
DTC No.Inspection itemApplyRelease*2Emergency brake (ASC)*3Emergency brake (EPB)*4
C1607ECU failureEnabled*5Enabled*5Enabled*5Enabled*5
C1707Implausible coding dataEnabledEnabledEnabledEnabled
C1861Power supply low voltageProhibitedProhibitedEnabledProhibited
C2253EPB SW malfunctionProhibitedProhibited*6/Enabled*7EnabledProhibited*7/Enabled*6
C2254IG SW malfunctionEnabledEnabledEnabledEnabled
C2300Left actuator malfunctionEnabled*8Enabled*8Enabled*8Enabled*8
C2301Right Actuator malfunctionEnabled*8Enabled*8Enabled*8Enabled*8
C2302Left Motor malfunctionEnabled*8Enabled*8Enabled*8Enabled*8
C2303Right Motor malfunctionEnabled*8Enabled*8Enabled*8Enabled*8
C2304Left +B voltage malfunctionEnabled*8Enabled*8Enabled*8Enabled*8
C2305Right +B voltage malfunctionEnabled*8Enabled*8Enabled*8Enabled*8
U0121ABS/ASC CAN timeoutProhibitedEnabledProhibitedEnabled*9
U0141ETACS CAN timeoutEnabledEnabledEnabledEnabled
U0415ABS/ASC (CAN message)Enabled*9EnabledEnabled*9Enabled*9
U1010PHEV ECU Parity/Toggle bit errorEnabledEnabledEnabledEnabled
U1073Bus-offProhibitedEnabled*12ProhibitedEnabled*9
U110APHEV-ECU CAN timeoutEnabledEnabledEnabledEnabled
U1195Coding not completedEnabledEnabledEnabledEnabled
-The power supply voltage is abnormal*10.ProhibitedProhibitedProhibitedProhibited
-The system detects a continuous operation of the electric parking brake (to protect the electric motor from overheat) *11ProhibitedEnabledEnabledEnabled*4
-The system detects that the electric parking brake is engaged poorly (the vehicle moves) continuously.EnabledEnabledEnabledProhibited
note
  • *1: The emergency brake will be activated when the brake pedal depression is not enough to decelerate the vehicle.
  • *2: The electric parking brake switch is operated or the automatic operation works.
  • *3: The ASC-ECU has applied the emergency brake hydraulically.
  • *4: Just in case the ASC-ECU cannot apply the parking brake hydraulically, the electric parking brake ECU applies the emergency brake instead.
  • *5: The ECU controls the system when possible.
  • *6: The release circuit of the electric parking brake switch fails.
  • *7: The apply circuit of the electric parking brake switch fails.
  • *8: The electric parking brake actuator, which corresponds to the DTC, is disabled.
  • *9: The system applies the emergency brake when vehicle speed signal is invalid.
  • *10: The power supply voltage is high or excessively low.
  • *11: If you operate the electric parking brake switch repeatedly in a short period of time, a warning screen will be displayed and the electric parking brake may be disabled temporarily. In this case, you have to wait for approximately one minute after the warning screen disappears until the switch can be operated.
  • *12: "Prohibited" when the ECU receives an invalid master cylinder fluid pressure sensor value or an invalid selector lever position.
 
 
HOW TO CONNECT THE SCAN TOOL (M.U.T.-IIISE)
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)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn off the power supply mode of the electric motor switch before connecting or disconnecting scan tool (M.U.T.-IIISE).
1. Ensure that the power supply mode of the electric motor switch should be turned off.
2. Start up the personal computer.
3. Connect special tool MB992747/M992748 or special tool MB991827 to special tool MB992744 or special tool MB991824 and the personal computer.
4. Connect special tool MB992745 or special tool MB991910 to special tool MB992744 or special tool MB991824.
5. Connect special tool MB992745 or special tool MB991910 to the data link connector.
noteWhen the special tool MB992745 is connected to the data link connector, the special tool MB992744 indicator light will be illuminated in a green color.
6. Turn the power switch of special tool MB991824 to the "ON" position. <When using the special tool MB991824>
noteWhen special tool MB991824 is energized, special tool MB991824 indicator light will be illuminated in a green color.
7. Start the M.U.T.-III system on the personal computer.
noteDisconnecting scan tool (M.U.T.-IIISE) is the reverse of the connecting sequence, making sure that the power supply mode of the electric motor switch should be turned off.
 
 
 
HOW TO READ AND ERASE DIAGNOSTIC TROUBLE CODES
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)
noteIf the 12V Starter Battery voltage is low, diagnostic trouble codes will not be set. Check the battery if scan tool (M.U.T.-IIISE) does not display.
1. Connect scan tool (M.U.T.-IIISE) to the data link connector.
2. Turn on the power supply mode of the electric motor switch.
3. Select "STV".
4. Select "EPB".
5. Select "Diagnostic Trouble Code" to read the DTC.
6. If a DTC is stored, it is shown.
7. Choose "Erase DTCs" to erase the DTC.
 
 
 
HOW TO DIAGNOSE THE CAN BUS LINES
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. Connect scan tool (M.U.T.-IIISE) to the data link connector.
2. Turn on the power supply mode of the electric motor switch.
3. Select "CAN bus diagnosis" from the system select screen.
4. When the optional equipment screen is displayed, choose the one which the vehicle is fitted with, and then select the "OK" button.