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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 analyzing 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 generatedkm/mile
2Ignition cycleNumber of times the ignition switch is turned ON or LOCK (OFF) after the past failure transitionNumber of counts is displayed.
3Right actuator currentRight actuator current when the DTC is generated.A
4Left actuator currentLeft actuator current when the DTC is generated.A
5Target currentTarget current when the DTC is generated.A
6Control vehicle speedVehicle speed (wheel speed) when the DTC is generatedr/min
7Power supply voltageVoltage of power supply when the DTC is generatedV
8Parking brake statusElectric parking brake control when the DTC is generated: Release/Lock/Lock -> Release/Release -> Lock/Unde- termined/EPB dynamic BRK/ASC dynamic BRK-
9EPB switch: LOCK 1 SWElectric parking brake switch (Lock switch 1) condition when the DTC is generated: OFF/ON/Open/Short-
10EPB switch: LOCK 2 SWElectric parking brake switch (Lock switch 2) condition when the DTC is generated: OFF/ON/Open/Short-
11EPB switch: RELEASE 1 SWElectric parking brake switch (Release switch 1) condition when the DTC is generated: OFF/ON/Open/Short-
12EPB switch: RELEASE 2 SWElectric parking brake switch (Release switch 2) condition when the DTC is generated: OFF/ON/Open/Short-
13Ignition switch (Hard wire)IG1 signal (hard wire) condition when the DTC is generated: OFF/ON-
14Acceleration pedalAccelerator pedal position sensor condition when the DTC is generated: OFF/ON-
15Shift informationShift condition when the DTC is generated: P/R/N/D-
16Driver's seat beltDriver's seat belt condition when the DTC is generated.: Not fastened/Fastened-
17Ignition switch (CAN)IG1 signal (CAN signal) condition when the DTC is generated: OFF/ON-
18Run mode (PHEV)Not used.-
19Master cylinder pressureMaster cylinder pressure of Master cylinder pressure sensor when the DTC is generated.MPa/psi
20Longitudinal GLongitudinal G of G and when the DTC is generated.m/s2
21Engine Torque (except PHEV)Engine torque condition when the DTC is generated.Nm
22Motor Torque (PHEV)Not used.-
 
 
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
DTCInspection 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
U0100Engine CAN timeoutOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
U0101T/M CAN timeoutOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
U0121ABS/ASC CAN timeoutOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
U0141ETACS CAN timeoutOFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
U0401Engine (CAN message)OFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
U0402T/M (CAN message)OFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
U0415ABS/ASC (CAN message)OFF*4ONPARKING BRAKE SERVICE REQUIREDOFF*4
U1073Bus-offOFF*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 approximately 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
DTCInspection itemApplyRelease*2Emergency brake (ASC)*3Emergency brake (EPB)*4
C1607ECU failureEnabled*5Enabled*5Enabled*5Enabled*5
C1707Implausible coding dataEnabledEnabledEnabledEnabled
C1861Power supply low voltageProhibitedEnabledEnabledProhibited
C2253EPB SW malfunctionProhibitedProhibited*6/Enabled*7ProhibitedProhibited
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
U0100Engine CAN timeoutEnabledEnabledEnabledEnabled
U0101T/M CAN timeoutEnabledEnabledEnabledEnabled
U0121ABS/ASC CAN timeoutProhibitedEnabledProhibitedEnabled*9
U0141ETACS CAN timeoutEnabledEnabledEnabledEnabled
U0401Engine (CAN message)EnabledEnabledEnabledEnabled
U0402T/M (CAN message)EnabledEnabledEnabledEnabled
U0415ABS/ASC (CAN message)Enabled*9EnabledEnabled*9Enabled*9
U1073Bus-offProhibitedEnabled*12ProhibitedEnabled*9
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
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-IIISE).
1. Ensure that the ignition switch is at the "LOCK" (OFF) position.
2. Start up the personal computer.
3. Connect special tool MB992747/M992748 to special tool MB992744 and the personal computer.
4. Connect special tool MB992745 to special tool MB992744.
5. Connect special tool MB992745 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. Start the M.U.T.-IIISE system on the personal computer.
noteDisconnecting scan tool (M.U.T.-IIISE) is the reverse of the connecting sequence, first making sure that the ignition switch is at the "LOCK" (OFF) position.
 
 
 
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
noteIf the 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 the ignition switch to the "ON" position.
3. Select "STV".
4. Select "EPB".
5. Select "Diagnostic Trouble Code" to read the DTC.
6. If a DTC is set, 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
1. Connect scan tool (M.U.T.-IIISE) to the data link connector.
2. Turn the ignition switch to the "ON" position.
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.