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Vehicle Stability Control System (Diagnostic Codes & Symptom Tests): Overview Scion FR-S I

Anti-Lock/traction Control 15 illustrations ~1445 words

DESCRIPTION

If a malfunction in the SFI system is detected, the operation of VSC and TR(A)C is prohibited by the fail-safe function. When the signals from the engine are received normally, fail-safe control is canceled.

DTC No.DTC Detection ConditionTrouble Area
C1201Engine control system malfunction signal continues for 0.5 seconds while the vehicle is being driven.SFI system

These solenoids turn on when signals are received from the skid control ECU and they control the pressure acting on the wheel cylinders to control the braking force.

DTC No.DTC Detection ConditionTrouble Area
C1225 C1226 C1227 C1228 C1468 C1469 C146A C146BSolenoid valve signal does not match the check result.Solenoid circuit Solenoid valve (Brake actuator assembly)

The steering sensor signal is sent to the skid control ECU (brake actuator assembly) via the CAN communication system. When there is a malfunction in the CAN communication system, it will be detected by the steering sensor zero point malfunction diagnostic function.

DTC CodeDTC Detection ConditionTrouble Area
C1231When the +BS terminal voltage is between 9.6 and 16.5 V, the steering sensor malfunction signal is received.Steering sensor Steering sensor circuit Steering sensor power supply

Scheme 11

Scheme 11: WIRING DIAGRAM
DTC No.DTC Detection ConditionTrouble Area
C1234Internal failure of the skid control ECU (Yaw rate sensor).Skid control ECU (Brake actuator assembly)
C1419Internal failure of the skid control ECU (Acceleration sensor).
C1472Internal failure of the skid control ECU (Lateral G sensor).
C1474Internal failure of the skid control ECU (Forward and backward G sensor).

The skid control ECU (brake actuator assembly) measures the speed of each wheel by receiving signals from the speed sensor.

These signals are used for recognizing that all four wheels are operating properly.

Therefore, all wheel signals must be equal.

DTCs C1275 to C1278 are cleared when the speed sensor sends a vehicle speed signal or when Test Mode ends. DTCs C1275 to C1278 are output only in Test Mode.

DTC No.DTC Detection ConditionTrouble Area
C1237Any of the following is detected: Discrepancy among four wheel speed sensor output. Abnormal pulse signals from 3 or more sensors. Continuous ABS control is performed for a long time. VSC control is performed for a long time.Tire and wheel size Tire deformation Speed sensor rotor Speed sensor Speed sensor circuit Skid control ECU (Brake actuator assembly)
C1275 C1276Detected only during Test Mode.Front speed sensor rotor RH/LH (Front axle hub sub-assembly RH/LH)
C1277 C1278Detected only during Test Mode.Rear speed sensor rotor RH/LH (Rear axle hub and bearing assembly RH/LH)

HINT

  1. DTC C1275 is for the front speed sensor RH.
  2. DTC C1276 is for the front speed sensor LH.
  3. DTC C1277 is for the rear speed sensor RH.
  4. DTC C1278 is for the rear speed sensor LH.

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 canceled when the +BS terminal voltage returns to normal.

DTC No.DTC Detection ConditionTrouble Area
C1241Any of the following is detected: The vehicle speed is 6 km/h (4 mph) or more and the +BS terminal voltage (soft low voltage) is 9.6 V or less for 1 second or more. The vehicle speed is 6 km/h (4 mph) or more and the +BS terminal voltage (hard low voltage) is 6.9 V or less for 1 second or more. The vehicle speed is 15 km/h (9 mph) or more, 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.*ABS NO. 2 fuse ECU IG1 fuse Battery Charging system Power source circuit Ground circuit 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.

Scheme 12

Scheme 12: WIRING DIAGRAM

The master cylinder pressure sensor is connected to the skid control ECU in the brake actuator assembly.

Scheme 13

Scheme 13: DESCRIPTION
DTC No.DTC Detection ConditionTrouble Area
C1246Any of the following is detected: The voltage of the sensor signal is out of range. The sensor signal offset value is out of range.STOP fuse Stop light switch circuit Master cylinder pressure sensor circuit Master cylinder pressure sensor (Brake actuator assembly)

The skid control ECU (brake actuator assembly) receives stop light switch signals and uses them to determine whether or not the brakes are applied.

DTCs may be stored if one of the following occurs

  1. Stop light switch stuck on/off malfunction.
  2. Accelerator pedal and brake pedal depressed simultaneously.*

HINT

*: The skid control ECU (brake actuator assembly) may store this DTC upon judging that a stuck on malfunction has occurred when the accelerator pedal and brake pedal are depressed simultaneously. However, this does not indicate a malfunction.

DTC No.DTC Detection ConditionTrouble Area
C1249Any of the following is detected: The vehicle speed is 10 km/h (6 mph) or more, the accelerator pedal is depressed, and the stop light switch is on for 60 seconds or more. When the stop light switch is off, the master cylinder pressure is increased.STOP fuse Stop light switch assembly Noise filter Stop light switch circuit Skid control ECU (Brake actuator assembly)

Scheme 14

Scheme 14: WIRING DIAGRAM

Each speed sensor detects wheel speed and sends the appropriate signals to the skid control ECU (brake actuator assembly). These signals are used by the brake control system.

Speed sensor rotors have row of alternating N and S magnetic poles, and their magnetic fields change when the rotors turn.

Each speed sensor detects that magnetic field change and sends a pulse signal to the skid control ECU (brake actuator assembly).

DTCs C1271 and C1272 are cleared when the speed sensor sends a vehicle speed signal or when Test Mode ends. DTCs C1271 and C1272 are output only in Test Mode.

Scheme 15

Scheme 15: DESCRIPTION
DTC No.DTC Detection ConditionTrouble Area
C1330 C1331An open or short in the speed sensor signal circuit.Front speed sensor RH/LH Speed sensor circuit Sensor installation Skid control ECU (Brake actuator assembly)
C1464 C1465An abnormal signal is received from a wheel speed sensor.Front speed sensor RH/LH Speed sensor circuit Front speed sensor rotor RH/LH (Front axle hub sub-assembly RH/LH) Sensor installation Skid control ECU (Brake actuator assembly)
C1271 C1272Detected only during Test Mode.Front speed sensor RH/LH Sensor installation Front speed sensor rotor RH/LH (Front axle hub sub-assembly RH/LH)

HINT

  1. DTCs C1271, C1330 and C1464 are for the front speed sensor RH.
  2. DTCs C1272, C1331 and C1465 are for the front speed sensor LH.

Scheme 16

Scheme 16: WIRING DIAGRAM

Each speed sensor detects the wheel speed and sends the appropriate signals to the skid control ECU (brake actuator assembly). These signals are used by the brake control system.

Speed sensor rotors have row of alternating N and S magnetic poles, and their magnetic fields change when the rotors turn.

Each speed sensor detects that magnetic field change and sends a pulse signal to the skid control ECU (brake actuator assembly).

DTCs C1273 and C1274 are cleared when the speed sensor sends a vehicle speed signal or when Test Mode ends. DTCs C1273 and C1274 are output only in Test Mode.

DTC No.DTC Detection ConditionTrouble Area
C1332 C1333An open or short in the speed sensor signal circuit.Rear speed sensor RH/LH Speed sensor circuit Sensor installation Skid control ECU (Brake actuator assembly)
C1466 C1467An abnormal signal is received from a wheel speed sensor.Rear speed sensor RH/LH Speed sensor circuit Rear speed sensor rotor RH/LH (Rear axle hub and bearing assembly RH/LH) Sensor installation Skid control ECU (Brake actuator assembly)
C1273 C1274Detected only during Test Mode.Rear speed sensor RH/LH Sensor installation Rear speed sensor rotor RH/LH (Rear axle hub and bearing assembly RH/LH)

HINT

  1. DTCs C1273, C1332 and C1466 are for the rear speed sensor RH.
  2. DTCs C1274, C1333 and C1467 are for the rear speed sensor LH.

Scheme 17

Scheme 17: WIRING DIAGRAM

The skid control ECU stores this DTC when the previously learned values in the VSC system and the engine information sent from the ECM are inconsistent, or when the learning has not completed after the skid control ECU (brake actuator assembly) is replaced with a new one.

DTC No.DTC Detection ConditionTrouble Area
C1288ECM does not match.ECM

If a malfunction in the automatic transmission system is detected, the operation of VSC and TR(A)C is prohibited by the fail-safe function. When the signals from the automatic transmission are received normally, fail-safe control is canceled.

DTC No.DTC Detection ConditionTrouble Area
C1201An abnormal signal is received from the automatic transmission.Automatic transmission system

The skid control ECU stores this DTC if malfunctions are found in the circuit inside the ECU by self diagnosis.

DTC No.DTC Detection ConditionTrouble Area
C1300Internal failure of the skid control ECU.Skid control ECU (Brake actuator assembly)

The ABS motor relay supplies power to the pump motor. While the ABS is activated, the skid control ECU turns the ABS motor relay on to operate the pump motor.

If the voltage supplied to the ABS motor relay (+BM) is too low due to low voltage from the battery or alternator, the DTC may be stored.

DTC No.DTC Detection ConditionTrouble Area
C146CAny of the following is detected: When the ABS motor relay is actuated, voltage is not supplied to the pump motor. When the ABS motor relay is not actuated, voltage in the pump motor is high. The skid control ECU judges that pump motor operation is abnormal.ABS NO. 1 fuse (Fusible link block assembly) ABS motor relay circuit ABS motor relay (Brake actuator assembly)

Scheme 18

Scheme 18: WIRING DIAGRAM

The ABS solenoid relay is built into the skid control ECU in the brake actuator assembly.

The ABS solenoid relay supplies power to the ABS and TR(A)C solenoids.

The skid control ECU detects a solenoid relay malfunction by performing a self check and relay operation check.

DTC No.DTC Detection ConditionTrouble Area
C146EEither of the following is detected: A solenoid relay drive circuit in the skid control ECU is malfunctioning. The solenoid relay cannot be switched between on and off.ABS NO. 2 fuse (Fusible link block assembly) ABS solenoid relay circuit ABS solenoid relay (Brake actuator assembly)

Scheme 19

Scheme 19: WIRING DIAGRAM

The skid control ECU (brake actuator assembly) receives signals from the ECM, steering sensor and TCM via the CAN communication system.

DTC No.DTC Detection ConditionTrouble Area
U0073The +BS terminal voltage is between 9.6 and 16.5 V and bus off is judged for 0.1 seconds or more.CAN communication system
U0100The +BS terminal voltage is between 9.6 and 16.5 V, the vehicle is being driven, and signals cannot be sent to the ECM for 0.5 seconds or more.CAN communication system Skid control ECU (Brake actuator assembly) ECM
U0123The +BS terminal voltage is between 9.6 and 16.5 V, the vehicle is being driven, and signals cannot be sent to the TCM for 0.5 seconds or more.CAN communication system Skid control ECU (Brake actuator assembly) TCM
U0126The +BS terminal voltage is between 9.6 and 16.5 V, the vehicle is being driven, and signals from the steering sensor cannot be received for 0.1 seconds or more.CAN communication system Skid control ECU (Brake actuator assembly) steering sensor

The skid control ECU (brake actuator assembly) is connected to the combination meter assembly via CAN communication.

If any of the following is detected, the ABS warning light remains on

  1. The skid control ECU (brake actuator assembly) connector is disconnected from the skid control ECU (brake actuator assembly).
  2. There is a malfunction in the skid control ECU (brake actuator assembly) internal circuit.
  3. There is an open in the harness between the combination meter assembly and the skid control ECU (brake actuator assembly).
  4. The ABS control system is defective.

HINT

In some cases, the Techstream cannot be used when the skid control ECU (brake actuator assembly) is abnormal.

Scheme 20

Scheme 20: WIRING DIAGRAM

The skid control ECU (brake actuator assembly) is connected to the combination meter assembly via CAN communication.

The skid control ECU (brake actuator assembly) is connected to the combination meter assembly via CAN communication.

If any of the following is detected, the brake warning light remains on

  1. The skid control ECU (brake actuator assembly) connector is disconnected from the skid control ECU (brake actuator assembly).
  2. The brake fluid level is insufficient.
  3. The parking brake is applied.
  4. EBD operation is not possible.

Scheme 21

Scheme 21: WIRING DIAGRAM

The skid control ECU (brake actuator assembly) is connected to the combination meter assembly via CAN communication.

The skid control ECU (brake actuator assembly) is connected to the combination meter assembly via CAN communication.

Pressing the VSC OFF switch turns off TR(A)C, and pressing and holding this switch turns off TR(A)C and VSC. If TR(A)C is turned off, the TR(A)C OFF indicator light will come on.

Scheme 22

Scheme 22: WIRING DIAGRAM

The skid control ECU (brake actuator assembly) is connected to the combination meter assembly via CAN communication.

The skid control ECU (brake actuator assembly) is connected to the combination meter assembly via CAN communication.

Pressing the VSC OFF switch turns off TR(A)C and pressing and holding this switch turns off TR(A)C and VSC. If VSC is turned off, the VSC OFF indicator light will come on.

Scheme 23

Scheme 23: WIRING DIAGRAM

The skid control ECU (brake actuator assembly) is connected to the combination meter assembly via CAN communication.

The skid control ECU (brake actuator assembly) is connected to the combination meter assembly via CAN communication.

When the VSC SPORT switch is operated, the system switches between normal mode and sport mode.

If the VSC SPORT switch is pressed in normal mode, the system enters sport mode.

Scheme 24

Scheme 24: WIRING DIAGRAM

The skid control ECU (brake actuator assembly) is connected to the combination meter assembly via CAN communication.

The skid control ECU (brake actuator assembly) is connected to the combination meter assembly via CAN communication.

The slip indicator light blinks during VSC and/or TR(A)C operation.

If a malfunction is detected, the slip indicator light comes on to warn the driver. Refer to DIAGNOSIS SYSTEM [07/2013 - ].

Scheme 25

Scheme 25: WIRING DIAGRAM

The skid control ECU (brake actuator assembly) is connected to the combination meter assembly via CAN communication.