DTC C123A: ABNORMALITY IN SENSOR CALIBRATION
| CAUTION | If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code may be set. Prior to this diagnosis, diagnose the CAN bus lines (Refer to CAN BUS LINE DIAGNOSTIC FLOW ). Whenever ECU is replaced, ensure that the CAN bus lines are normal. When the steering wheel sensor is replaced, always carry out calibration to make ASC-ECU learn the neutral point (Refer to STEERING WHEEL SENSOR CALIBRATION ). Do not drop or shock the G and yaw rate sensor. When the G and yaw rate sensor is replaced, always carry out calibration to make ASC-ECU learn the neutral point (Refer to G AND YAW RATE SENSOR CALIBRATION ). When the hydraulic unit (integrated with ASC-ECU) is replaced, always carry out the calibration of the steering wheel sensor, the G and yaw rate sensor and brake fluid pressure sensor (Refer to G AND YAW RATE SENSOR CALIBRATION , STEERING WHEEL SENSOR CALIBRATION and BRAKE FLUID PRESSURE SENSOR CALIBRATION ). |
HYDRAULIC UNIT INSTALLATION ADJUSTMENT
Refer to HYDRAULIC UNIT .
- Operate the pre-removal steps for the hydraulic unit.
- Remove all brake tubes.
- Remove the protector.
- Loosen the mounting bolt and nut of the hydraulic unit bracket.
- Install all brake tubes temporarily.
- Shake hydraulic unit to all directions with both hands to make the hydraulic unit bracket insulator fit with the unit.
- Install the hydraulic unit bracket with mounting bolt and nut not to load the brake tube.
- Install the protector.
- Install all brake tubes securely. NOTE: Install the flare nut taking care not to let the brake tube turn together.
- Operate the post-installation steps of the hydraulic unit.
ALL SENSOR CALIBRATION (G AND YAW RATE SENSOR, STEERING WHEEL SENSOR, BRAKE FLUID PRESSURE SENSOR)
| CAUTION | Before carrying out the calibration, check that the diagnostic trouble code related to the steering wheel sensor, G and yaw rate sensor, or brake fluid pressure sensor is not set. |
| CAUTION | When the next operation has been completed, carry out the calibration to make ASC-ECU learn the neutral point of the steering wheel sensor, G and yaw rate sensor, and brake fluid pressure sensor. ASC-ECU replacement |
| CAUTION | Carry out the calibration under the following conditions. The vehicle has one occupant (driver) only. Turn the steering wheel to set the wheels in the straight-ahead positions. The brake pedal is not depressed. (The stop light switch is OFF). |
- Park the vehicle on a level surface. CAUTION: Before connecting or disconnecting scan tool, always turn the ignition switch to the LOCK (OFF) position.
- Before setting scan tool, turn the ignition key to the LOCK (OFF) position.
- Turn the ignition switch to the ON position.
- Select "ABS/ASC/ASTC."
- Select "Special function."
- Select "Sensor calibration."
- Select "all sensor calibration."
- Before removing scan tool from the vehicle, turn the ignition key to the LOCK (OFF) position.
G AND YAW RATE SENSOR CALIBRATION
| CAUTION | Before performing calibration, check that the G and yaw rate sensor-related diagnosis code is not set. |
| CAUTION | After the next operation has been completed, carry out the calibration to make ASC-ECU learn the neutral position of the G and yaw rate sensor. G and yaw rate sensor replacement ASC-ECU replacement |
- Park the vehicle on a level surface. CAUTION: Before connecting or disconnecting the scan tool, turn the ignition switch to the "LOCK" (OFF) position.
- Set the scan tool with the ignition "LOCK" (OFF).
- Turn the ignition switch to the ON position.
- Select the relevant system from the menu.
- Select "ABS/ASC/ASTC" from the system lists in "System select", and press "OK" button.
- Select "Special function" in "ABS/ASC/ASTC".
- Select "Sensor calibration" in "Special function".
- Select "G sensor calibration" from the selected item, and press "OK" button.
- The screen displays "G sensor calibration: The selected command will be executed. Are you sure? Caution: Please check the execution conditions." Then press "OK" button.
- "Execute: The command was executed." will be shown. Then press "OK" button.
- Select "Lateral/G sensor calibration" from the selected item, and press "OK" button.
- The screen displays "Lateral/G sensor calibration: The selected command will be executed. Are you sure? Caution: Please check execution conditions." Then press "OK" button.
- "Executed: The command was executed." will be shown. Then press "OK" button.
- Learning neutral point complete
- Turn the ignition switch to "LOCK" (OFF) position and then disconnect the scan tool.
STEERING WHEEL SENSOR CALIBRATION
| CAUTION | After the next operation has been completed, carry out the following two operations: Alignment adjustment < Front > Steering wheel sensor (column switch assembly) replacement, removal, installation ASC-ECU replacement When the steering wheel sensor is replaced or installed, perform "Steering angle correction amount initialization" of the AWC-ECU. Update the neutral position stored in the steering wheel sensor. Reset the calibrated value of the steering angle stored in ASC-ECU. |
| CAUTION | Before performing the calibration, check if the steering wheel sensor-related diagnosis code is set in ASC-ECU. When the diagnosis code other than C121A is set, carry out inspection according to each troubleshooting procedure. |
- Place the vehicle on a level surface with its road wheels in the straight ahead position. CAUTION: Before connecting or disconnecting the scan tool, turn the ignition switch to the "LOCK" (OFF) position.
- Set the scan tool with the ignition at "LOCK" (OFF).
- Ignition switch: ON
- Select the relevant system from the menu.
- Select "Steering angle sensor" from the system list in "System select", and press "OK" button.
- Select "Special function" under "Steering angle sensor".
- Select "SAS Calibration" under "Special function". NOTE: If the steering angle sensor neutral point has been learned, the display will show "If SAS needs re-calibration, execute SAS calibration after executing SAS initialization". If yes, press "OK" button.
- As "SAS initialization" is selected under "SAS Calibration", press "OK" button. NOTE: At this time, if the steering angle sensor neutral point has been learned, the display will show "Do you want to start? Note This operation will dear DTCs". Then, press "OK" button.
- The display should show "Completed." Press "OK" button.
- Press the OK button.
- The display should show "SAS Calibration: Do you want to start?". Then press the OK button. NOTE: Please execute after making a tire and a steering wheel straight.
- The display should show "Completed." Press "OK" button.
- Turn the ignition switch to "LOCK" (off) position, and then turn the ignition switch ON again.
- Select the relevant system from the menu.
- Select "ABS/ASC/ASTC" from the system list under "System select", and press "OK" button.
- Select "Special function" under "ABS/ASC/ASTC".
- Select "Sensor calibration" under "Special function".
- Select "SAS calibration" under "Sensor calibration", and press "OK" button.
- The screen displays "SAS calibration: The selected command will be executed. Are you sure? Caution: Confirm the execution conditions." Then press "OK" button.
- "Executed: The command was executed." will be shown. Then press "OK" button.
- Select "Diagnostic trouble code" under "ABS/ASC/ASTC". If the diagnostic trouble code "C2205 SAS internal failure (past trouble)" is set, clear it.
- Learning neutral point complete
- Turn the ignition switch to "LOCK" (OFF) position and then disconnect the scan tool.
BRAKE FLUID PRESSURE SENSOR CALIBRATION
| CAUTION | Prior to calibration, check that no brake fluid pressure sensor-related diagnostic trouble codes are set. |
| CAUTION | After the following procedure is complete, carry out calibration to let the ASC-ECU learn the neutral position of the brake fluid pressure sensor. During diagnosis according to diagnostic trouble code No. C123A ASC-ECU replacement |
| CAUTION | During the calibration, the brake pedal should be released (the stoplight switch should be off). |
- Park the vehicle on a level surface. CAUTION: Before connecting or disconnecting the scan tool, turn the ignition switch to the "LOCK" (OFF) position.
- Set the scan tool with the ignition at "LOCK" (OFF).
- Turn the ignition switch to the ON position.
- Select the relevant system from the menu.
- Select "ABS/ASC/ASTC/WSS" from the system list under "System select", and press "OK" button.
- Select "Special function" under "ABS/ASC/ASTC/WSS".
- Select "Sensor calibration" under "Special function".
- Select "M/C pressure sensor calibration" from the selected item, and press "OK" button.
- The screen displays "M/C pressure sensor calibration: The selected command will be executed. Are you sure? Caution: Please check execution conditions." Then press "OK" button.
- "Executed: The command was executed." will be shown. Then press "OK" button.
- Learning neutral point complete
- Turn the ignition switch to "LOCK" (OFF) position and then disconnect the scan tool.
Scheme 3
Scheme 3: REMOVAL AND INSTALLATION
Scheme 4
Scheme 4: ASC OFF SWITCH CONTINUITY CHECK
- As shown in the illustration, connect the circuit tester to the ASC OFF switch as a single unit.
- Check the continuity when the ASC OFF switch is pressed and released. ASC OFF SWITCH CONTINUITY CHECK Item When the ASC OFF switch is released (No operation status) When the ASC OFF switch is pressed Continuity between terminal No. 1 and No. 2 No continuity Continuity exists. (2 ohms or less) Continuity between terminal No. 3 and No. 4 Continuity exists. Continuity exists.
