Last Modified: 05-13-2024 |
6.11:8.1.0 |
Doc ID: RM10000000260S6 |
Model Year Start: 2023 |
Model: GR Corolla |
Prod Date Range: [09/2022 -
] |
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for Gasoline Model without Electric Parking Brake System TMC Made): C137BA2; Brake System Control Module "A" System Voltage System Voltage Low; 2023 - 2025 MY Corolla Corolla Hatchback GR Corolla [09/2022 - ] |
DTC
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C137BA2
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Brake System Control Module "A" System Voltage System Voltage Low
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DESCRIPTION
If a malfunction is detected in the power supply circuit, the skid control ECU (brake actuator assembly) stores this DTC and the fail-safe function prohibits operation of ABS, brake assist, etc.
This DTC is stored when the +BS terminal voltage meets one of the DTC detection conditions due to a malfunction in the power supply or charging circuit such as the battery or alternator circuit, etc.
The DTC is cleared when the +BS terminal voltage returns to normal.
DTC No.
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Detection Item
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DTC Detection Condition
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Trouble Area
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C137BA2
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Brake System Control Module "A" System Voltage System Voltage Low
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Any of the following is detected:
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When the +BS terminal voltage is below 9.5 V, the power source voltage for all speed sensors is continuously low for 60 seconds or more.
-
After the +BS terminal voltage is below 9.5 V continuously for 3 seconds or more, the +BS terminal voltage is below 9.5 V continuously for 7 seconds or more at a vehicle speed exceeding 3 km/h (2 mph).
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When the +BS terminal voltage is 9.5 V or higher and the vehicle speed exceeds 15 km/h (9 mph), the IGR terminal voltage is 10 V or less continuously for 60 seconds or more.
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When the +BS terminal voltage is below 9.5 V and the solenoid relay is ON, the relay contact is OFF continuously for 1.22 seconds or more.
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When the +BS terminal voltage is below 9.5 V, motor fail-safe relay overcurrent continues for 1.05 seconds or more.
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-
Wire harness and connector
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Skid control ECU (brake actuator assembly)
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WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
-
Inspect the fuses for circuits related to this system before performing the following procedure.
-
Before performing troubleshooting, make sure to confirm that the battery voltage is normal.
Click here
PROCEDURE
1.
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CHECK HARNESS AND CONNECTOR (+BS TERMINAL)
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(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
OK:
The connector is securely connected.
|
|
*a
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Front view of wire harness connector
(to Skid Control ECU (Brake Actuator Assembly))
|
|
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(b) Disconnect the A140 skid control ECU (brake actuator assembly) connector.
(c) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(d) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection
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Condition
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Specified Condition
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A140-14 (+BS) - Body ground
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Always
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11 to 14 V
|
NG |
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REPAIR OR REPLACE HARNESS OR CONNECTOR
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OK
|
|
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2.
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CHECK HARNESS AND CONNECTOR (IGR TERMINAL)
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(a) Turn the ignition switch to ON.
|
|
*a
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Front view of wire harness connector
(to Skid Control ECU (Brake Actuator Assembly))
|
|
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(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection
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Condition
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Specified Condition
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A140-45 (IGR) - Body ground
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Ignition switch ON
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11 to 14 V
|
NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR
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OK
|
|
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3.
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CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)
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(a) Turn the ignition switch off.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
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Condition
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Specified Condition
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A140-1 (GND1) - Body ground
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1 minute or more after disconnecting the cable from the negative (-) battery terminal
|
Below 1 Ω
|
NG |
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REPAIR OR REPLACE HARNESS OR CONNECTOR
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OK
|
|
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(a) Reconnect the A140 skid control ECU (brake actuator assembly) connector.
(b) Clear the DTCs.
Chassis > Brake/EPB > Clear DTCs
(c) Turn the ignition switch off.
NEXT
|
|
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(a) Based on the Freeze Frame Data and interview with the customer, attempt to reproduce the conditions when the malfunction occurred.
(b) Check if the same DTC is output.
Chassis > Brake/EPB > Trouble Codes
Result
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Proceed to
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DTC C137BA2 is not output.
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A
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DTC C137BA2 is output.
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B
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