DIAGNOSTIC FUNCTION


Electric parking brake ECU has the following functions for easier system checks.

All the above items can be diagnosed using M.U.T.-III.

CHECK OF FREEZE FRAME DATA


The freeze frame data can be checked by using the M.U.T.-III.
When detecting fault and setting the diagnosis code, the ECU connected to CAN bus line obtains the data before the determination of the diagnosis code and the data when the diagnosis code is determined, and then stores the ECU status of that time. By analysing each data from M.U.T.-III, the troubleshooting can be performed more efficiently. The displayed items are as the table below.

Display item list
Item No.
 Item name
 Data item
 Unit
1
 Odometer
 Total driving distance after the diagnosis code is generated
 km
2
 Ignition cycle
 Number of times the ignition switch is turned ON or LOCK (OFF) after the past failure transition
 Number of counts is displayed.
3
 Right actuator current
 Right actuator current when the diagnosis code is generated.
 A
4
 Left actuator current
 Left actuator current when the diagnosis code is generated.
 A
5
 Target current
 Target current when the diagnosis code is generated.
 A
6
 Control vehicle speed
 Vehicle speed (wheel speed) when the diagnosis code is generated
 r/min
7
 Power supply voltage
 Voltage of power supply when the diagnosis code is generated
 V
8
 Parking brake status
 Electric parking brake control when the diagnosis code is generated: Release/Lock/Lock -> Release/Release -> Lock/Undefined/EPB dynamic BRK/ASC dynamic BRK
 -
9
 EPB switch:LOCK 1 SW
 Electric parking brake switch (Lock switch 1) condition when the diagnosis code is generated: OFF/ON/Open/Short
 -
10
 EPB switch:LOCK 2 SW
 Electric parking brake switch (Lock switch 2) condition when the diagnosis code is generated: OFF/ON/Open/Short
 -
11
 EPB switch:RELEASE 1 SW
 Electric parking brake switch (Release switch 1) condition when the diagnosis code is generated: OFF/ON/Open/Short
 -
12
 EPB switch:RELEASE 2 SW
 Electric parking brake switch (Release switch 2) condition when the diagnosis code is generated: OFF/ON/Open/Short
 -
13
 Ignition switch (Hard wire)
 IG1 signal (hard wire) condition when the diagnosis code is generated: OFF/ON
 -
14
 Acceleration pedal
 Accelerator pedal position sensor condition when the diagnosis code is generated: OFF/ON
 -
15
 Shift information
 Shift condition when the diagnosis code is generated: P/R/N/D
 -
16
 Driver’s seat belt
 Driver’s seat belt condition when the diagnosis code is generated.: Not fastened/Fastened
 -
17
 Ignition switch (CAN)
 IG1 signal (CAN signal) condition when the diagnosis code is generated: OFF/ON
 -
18
 Run mode (PHEV)
 Not used.
 -
19
 Master cylinder pressure
 Master cylinder pressure of Master cylinder pressure sensor when the diagnosis code is generated.
 MPa
20
 Longitudinal G
 Longitudinal G of G and when the diagnosis code is generated.
 m/s2
21
 Engine Torque (except PHEV)
 Engine torque condition when the diagnosis code is generated.
 Nm
22
 Motor 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 lamp, the electric parking brake warning lamp and the electric parking brake switch indicator lamp 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 lamp, indicator lamp and multi information display in case of failure


Diagnosis code No.
 Inspection item
 Brake warning lamp
 Electric parking brake warning lamp
 Multi information display
 Electric parking brake switch indicator lamp
C1607
 ECU failure
 OFF
 ON
 PARKING BRAKE SERVICE REQUIRED
 OFF
C1707
 Implausible coding data
 OFF
 ON
 PARKING BRAKE SERVICE REQUIRED
 OFF
C1861
 Power supply low voltage
 Flash (1 Hz)
 OFF
 -
 Flash (1 Hz)
C2253
 EPB SW malfunction
 Flash (1 Hz)*1
 ON
 PARKING BRAKE SERVICE REQUIRED
 Flash (1 Hz)*1
C2254
 IG SW malfunction
 OFF
 ON
 PARKING BRAKE SERVICE REQUIRED
 OFF
C2300
 Left actuator malfunction
 Flash (1 Hz)
 ON
 PARKING BRAKE SERVICE REQUIRED
 Flash (1 Hz)
C2301
 Right Actuator malfunction
 Flash (1 Hz)
 ON
 PARKING BRAKE SERVICE REQUIRED
 Flash (1 Hz)
C2302
 Left Motor malfunction
 OFF
 ON
 PARKING BRAKE SERVICE REQUIRED
 OFF
C2303
 Right Motor malfunction
 OFF
 ON
 PARKING BRAKE SERVICE REQUIRED
 OFF
C2304
 Left +B voltage malfunction
 OFF
 ON
 PARKING BRAKE SERVICE REQUIRED
 OFF
C2305
 Right +B voltage malfunction
 OFF
 ON
 PARKING BRAKE SERVICE REQUIRED
 OFF
U0100
 Engine CAN timeout
 OFF
 ON
 PARKING BRAKE SERVICE REQUIRED
 OFF
U0101
 T/M CAN timeout
 OFF
 ON
 PARKING BRAKE SERVICE REQUIRED
 OFF
U0121
 ABS/ASC CAN timeout
 OFF
 ON
 PARKING BRAKE SERVICE REQUIRED
 OFF
U0141
 ETACS CAN timeout
 OFF
 ON
 PARKING BRAKE SERVICE REQUIRED
 OFF
U0401
 Engine (CAN message)
 OFF
 ON
 PARKING BRAKE SERVICE REQUIRED
 OFF
U0402
 T/M (CAN message)
 OFF
 ON
 PARKING BRAKE SERVICE REQUIRED
 OFF
U0415
 ABS/ASC (CAN message)
 OFF
 ON
 PARKING BRAKE SERVICE REQUIRED
 OFF
U1073
 Bus-off
 OFF
 ON
 PARKING BRAKE SERVICE REQUIRED
 OFF
U1195
 Coding not completed
 OFF
 ON
 PARKING BRAKE SERVICE REQUIRED
 OFF
-
 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)
 OFF
 PARKING BRAKE TEMPORARILY NOT AVAILABLE
 Flash (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 lamp 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.

Under apply, release and emergency brake*1 in case of failure


Diagnosis code No.
 Inspection item
 Apply
 Release*2
 Emergency brake (ASC)*3
 Emergency brake (EPB)*4
C1607
 ECU failure
 Enabled*5
 Enabled*5
 Enabled*5
 Enabled*5
C1707
 Implausible coding data
 Enabled
 Enabled
 Enabled
 Enabled
C1861
 Power supply low voltage
 Prohibited
 Prohibited
 Enabled
 Prohibited
C2253
 EPB SW malfunction
 Prohibited
 Prohibited*6/Enabled*7
 Enabled
 Prohibited
C2254
 IG SW malfunction
 Enabled
 Enabled
 Enabled
 Enabled
C2300
 Left actuator malfunction
 Enabled*8
 Enabled*8
 Enabled*8
 Enabled*8
C2301
 Right Actuator malfunction
 Enabled*8
 Enabled*8
 Enabled*8
 Enabled*8
C2302
 Left Motor malfunction
 Enabled*8
 Enabled*8
 Enabled*8
 Enabled*8
C2303
 Right Motor malfunction
 Enabled*8
 Enabled*8
 Enabled*8
 Enabled*8
C2304
 Left +B voltage malfunction
 Enabled*8
 Enabled*8
 Enabled*8
 Enabled*8
C2305
 Right +B voltage malfunction
 Enabled*8
 Enabled*8
 Enabled*8
 Enabled*8
U0100
 Engine CAN timeout
 Enabled
 Enabled
 Enabled
 Enabled
U0101
 T/M CAN timeout
 Enabled
 Enabled
 Enabled
 Enabled
U0121
 ABS/ASC CAN timeout
 Prohibited
 Enabled
 Prohibited
 Enabled*9
U0141
 ETACS CAN timeout
 Enabled
 Enabled
 Enabled
 Enabled
U0401
 Engine (CAN message)
 Enabled
 Enabled
 Enabled
 Enabled
U0402
 T/M (CAN message)
 Enabled
 Enabled
 Enabled
 Enabled
U0415
 ABS/ASC (CAN message)
 Enabled*9
 Enabled
 Enabled*9
 Enabled*9
U1073
 Bus-off
 Prohibited
 Enabled
 Prohibited
 Enabled*9
U1195
 Coding not completed
 Enabled
 Enabled
 Enabled
 Prohibited
-
 The power supply voltage is abnormal*10.
 Prohibited
 Prohibited
 Prohibited
 Prohibited
-
 The system detects a continuous operation of the electric parking brake (to protect the electric motor from overheat) *11
 Prohibited
 Enabled
 Enabled
 Prohibited*4
-
 The system detects that the electric parking brake is engaged poorly (the vehicle moves) continuously.
 Enabled
 Enabled
 Enabled
 Enabled
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 diagnosis code, 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.

HOW TO READ DIAGNOSIS CODE


Refer to GROUP 00 - How to Use Troubleshooting and Inspection Service Points.

HOW TO ERASE DIAGNOSIS CODE


Refer to GROUP 00 - How to Use Troubleshooting and Inspection Service Points.