RM3660EC _54 Brake _080770 BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS _0599814 ELECTRONICALLY CONTROLLED BRAKE SYSTEM(for Gasoline Model (NR Series)) C

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS  ELECTRONICALLY CONTROLLED BRAKE SYSTEM(for Gasoline Model (NR Series))  C137BA2  Brake System Control Module "A" System Voltage System Voltage Low  


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 ABS operation.

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. Detection Item DTC Detection Condition Trouble Area
C137BA2 Brake System Control Module "A" System Voltage System Voltage Low Any of the following is detected:
1.

The vehicle speed is 6 km/h (4 mph) or more and the +BS terminal voltage (soft low voltage) is less than 9.6 V for 1 second or more.

2.

The vehicle speed is 6 km/h (4 mph) or more and the +BS terminal voltage (hard low voltage) is less than 6.9 V for 1 second or more.

3.

The +BS terminal voltage is less than 6.7 V and the skid control ECU (brake actuator assembly) judges that power supply voltage is abnormal for 0.06 seconds or more.

4.

The vehicle speed is 15 km/h (9 mph) or more and the +BS terminal voltage is 9.6 V or more, the skid control ECU (brake actuator assembly) turns on more than one valve at the same time within a short period of time and the valve relay supply voltage drop exceeds the threshold.*

5.

When the system has started, the +BS terminal voltage is less than 5 V for 0.5 seconds or more.

6.

The +BS terminal voltage is less than 2.6 V for 0.2 seconds or more.


·

Battery

·

Charging system

·

Internal power supply circuit of the skid control ECU (brake actuator assembly)



*: The skid control ECU (brake actuator assembly) monitors the resistance of the power source line at the +BS terminal. A malfunction is detected when an abnormality occurs in the +BS terminal wire harness or its connection and the skid control ECU (brake actuator assembly) determines that the wiring resistance at the +BS terminal exceeds the standard resistance.

DTC Detection Conditions: C137BA2
Vehicle Condition
Pattern 1 Pattern 2 Pattern 3 Pattern 4 Pattern 5 Pattern 6
Diagnosis Condition The vehicle speed is 6 km/h (4 mph) or more. ○ ○ - - - -
The vehicle speed is 15 km/h (9 mph) or more and the +BS terminal voltage is 9.6 V or more. - - - ○ - -
The system has started. - - - - ○ -
Malfunction Status The +BS terminal voltage (soft low voltage) is less than 9.6 V. ○ - - - - -
The +BS terminal voltage (hard low voltage) is less than 6.9 V. - ○ - - - -
The +BS terminal voltage is less than 6.7 V and the skid control ECU (brake actuator assembly) judges that power supply voltage is abnormal. - - ○ - - -
The skid control ECU (brake actuator assembly) turns on more than one valve at the same time within a short period of time and the valve relay supply voltage drop exceeds the threshold.* - - - ○ - -
The +BS terminal voltage is less than 5 V. - - - - ○ -
The +BS terminal voltage is less than 2.6 V. - - - - - ○
Detection Time 1 second or more. 1 second or more. 0.06 seconds or more. - 0.5 seconds or more. 0.2 seconds or more.
Number of Trips 1 trip 1 trip 1 trip 1 trip 1 trip 1 trip

*: The skid control ECU (brake actuator assembly) monitors the resistance of the power source line at the +BS terminal. A malfunction is detected when an abnormality occurs in the +BS terminal wire harness or its connection and the skid control ECU (brake actuator assembly) determines that the wiring resistance at the +BS terminal exceeds the standard resistance.

HINT:

DTC will be output when conditions for either of the patterns in the table above are met.


WIRING DIAGRAM

C408683E02
1.938,1.146 3.063,1.427 1.125,0.281 10 false from Battery 3.708,1.333 4.833,1.615 1.125,0.281 10 false ABS-MAIN 5.667,1.031 5.979,1.229 0.313,0.198 10 false 30 5.677,2.813 5.99,3.01 0.313,0.198 10 false 46 5.969,1.156 6.385,1.396 0.417,0.24 10 false +BS 5.969,2.938 6.385,3.177 0.417,0.24 10 false GND1 4.26,3.979 4.719,4.177 0.458,0.198 10 false A51 4.25,4.146 7.156,4.51 2.906,0.365 10 false Skid Control ECU (Brake Actuator Assembly) 3.719,1.021 3.875,1.219 0.156,0.198 10 false 1 4.208,1.031 4.365,1.229 0.156,0.198 10 false 2 1.938,2.042 3.063,2.323 1.125,0.281 10 false from Battery 3.708,2.219 4.833,2.5 1.125,0.281 10 false ABS MTR 4.188,1.906 4.344,2.104 0.156,0.198 10 false 2 3.719,1.917 3.875,2.115 0.156,0.198 10 false 1 5.719,1.917 6.031,2.115 0.313,0.198 10 false 1 5.969,2.042 6.385,2.281 0.417,0.24 10 false +BM

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 hereGeneral>INTRODUCTION>HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS>HOW TO PROCEED WITH TROUBLESHOOTING

·

After replacing the skid control ECU (brake actuator assembly), perform acceleration sensor zero point calibration and store system information memorization.

Click hereBrake>BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS>ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for Gasoline Model (NR Series))>HOW TO PROCEED WITH TROUBLESHOOTING



PROCEDURE

1.CHECK FREEZE FRAME DATA (BS1 VOLTAGE VALUE AND MOTOR POWER SUPPLY VOLTAGE)
a.

Select a DTC to display the Freeze Frame Data.


b.

Read the freeze frame data of DTC C137BA2.

Chassis > Brake/EPB
Tester Display Measurement Item Range Normal Condition Diagnostic Note
BS1 Voltage Value +BS terminal voltage value (value detected by ECU) Min.: 0.0 V, Max.: 25.5 V Ignition switch ON: 11.0 to 14.0 V Changes in proportion to battery voltage
HINT:

This is the voltage detected at terminal +BS (which supplies power to each solenoid) of the skid control ECU (brake actuator assembly)


Motor Power Supply Voltage +BM terminal voltage value (value detected by ECU) Min.: 0.0 V, Max.: 25.5 V Ignition switch ON: 11.0 to 14.0 V Changes in proportion to battery voltage
HINT:

This is the voltage detected at terminal +BM (which supplies power to the ABS motor) of the skid control ECU (brake actuator assembly)


Chassis > Brake/EPB > DTC(C137BA2) > Freeze Frame Data
Tester Display
BS1 Voltage Value
Motor Power Supply Voltage
50040 435 11,12 C137BA2

Result:
Result Proceed to
BS1 Voltage Value and Motor Power Supply Voltage are less than 9.6 V. A
Only BS1 Voltage Value is less than 9.6 V. B
Only Motor Power Supply Voltage is less than 9.6 V, or both BS1 Voltage Value and Motor Power Supply Voltage are 9.6 V or more. C



A

CHECK OR REPLACE CHARGING SYSTEM COMPONENT OR BATTERY

Click herePower Source / Network>NR Series (BATTERY / CHARGING)>CHARGING SYSTEM>ON-VEHICLE INSPECTION


B

2.READ VALUE USING GTS (BS1 VOLTAGE VALUE)

C

REPLACE BRAKE ACTUATOR ASSEMBLY

Click hereBrake>BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS>BRAKE ACTUATOR (for Gasoline Model)>REMOVAL


2.READ VALUE USING GTS (BS1 VOLTAGE VALUE)
a.

Start the engine.


b.

Follow the instructions on the screen to display the Data List, and perform the inspection.

Chassis > Brake/EPB > Data List
Tester Display Measurement Item Range Normal Condition Diagnostic Note
BS1 Voltage Value +BS terminal voltage value (value detected by ECU) Min.: 0.0 V, Max.: 25.5 V Ignition switch ON: 11.0 to 14.0 V Changes in proportion to battery voltage
HINT:

This is the voltage detected at terminal +BS (which supplies power to each solenoid) of the skid control ECU (brake actuator assembly)


Chassis > Brake/EPB > Data List
Tester Display
BS1 Voltage Value
50003 435 11

Result:
Result Proceed to
The value of BS1 Voltage Value is 9.6 V or more. A
The value of BS1 Voltage Value is less than 9.6 V. B



A

USE SIMULATION METHOD TO CHECK

Click hereGeneral>INTRODUCTION>HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS>HOW TO PROCEED WITH TROUBLESHOOTING


B

3.CHECK HARNESS AND CONNECTOR (+BS TERMINAL)
3.CHECK HARNESS AND CONNECTOR (+BS TERMINAL)
a.
C399487C36
0.333,0.229 0.75,0.479 0.417,0.25 0.833,1.802 0.667,1.052 true 0.094,0.104 0.406,0.26 0.313,0.156 10 false *a 0.427,0.281 0.885,0.479 0.458,0.198 10 false A51 0.729,1.865 1.188,2.063 0.458,0.198 10 false +BS
*a Front view of wire harness connector
(to Skid Control ECU (Brake Actuator Assembly))


Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.



b.

Disconnect the A51 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 Condition Specified Condition
A51-30 (+BS) - Body ground Always 9.6 V or higher



Result:
Proceed to
OK
NG



OK

4.CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)
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.



b.

Disconnect the A51 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 Condition Specified Condition
A51-46 (GND1) - Body ground 1 minute or more after disconnecting the cable from the negative (-) battery terminal Below 1 Ω



Result:
Proceed to
OK
NG



OK

REPLACE BRAKE ACTUATOR ASSEMBLY

Click hereBrake>BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS>BRAKE ACTUATOR (for Gasoline Model)>REMOVAL


NG

REPAIR OR REPLACE HARNESS OR CONNECTOR