Active Center Differential (ACD)

DTC C1242: G and Yaw Rate Sensor System (Abnormality of Longitudinal G Sensor Output Signal)

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.

- Whenever the ECU is replaced, ensure that the CAN bus lines are normal.

- Do not drop the G and yaw rate sensor or subject it to a shock.

- When G and yaw rate sensor is replaced, calibrate G and yaw rate sensor (refer to On-vehicle Service Testing and Inspection)

OPERATION

AWC-ECU receives the G and yaw rate sensor data from ASC-ECU via the CAN communication.

DTC set conditions

This diagnostic trouble code is set when the abnormality below is detected:

- Abnormality in G and yaw rate sensor output value

- This diagnostic trouble code is set when AWC-ECU determines that an abnormality is present by comparing the longitudinal G that is output from the G and yaw rate sensor during braking with the calculation value calculated by the data from the wheel speed sensor.

PROBABLE CAUSES

- Improper installation of G and yaw rate sensor

- Malfunction of G and yaw rate sensor

- Malfunction of wheel speed sensor

- Malfunction of stoplight switch

- Malfunction of AWC-ECU

- Malfunction of ASC-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Scan tool CAN bus diagnostics

Using scan tool MB991958, diagnose the CAN bus lines.

Q. Is the check result normal?

YES Go to Step 3.
NO Repair the CAN bus lines. CAN Bus Diagnostics Chart).
After repairing the CAN bus line, go to Step 2.
STEP 2. Check whether the DTC is reset.

Q. Is DTC No. C1242 set?

YES Go to Step 3.
NO This diagnosis is complete.
STEP 3. Scan tool diagnostic trouble code

Check the ASC diagnostic trouble code. Active Stability Control System (ASC)).

Q. Is the check result normal?

YES Perform the relevant troubleshooting.
NO Go to Step 4.
STEP 4. Scan tool diagnostic trouble code

Check if the stoplight switch-related, or wheel speed sensor-related diagnostic trouble code is set.

Q. Is the DTC set?

YES Perform the relevant troubleshooting.
NO Go to Step 5.
STEP 5. Check of G and yaw rate sensor installation status.

Check that the G and yaw rate sensor is installed correctly. Service and Repair).

Q. Is the check result normal?

YES Go to Step 6.
NO Reinstall the G and yaw rate sensor correctly. Then go to Step 6.
STEP 6. Scan tool data list

Item No.31: Longitudinal G sensor (Refer to Data List Reference Table).

Q. Is the check result normal?

YES Go to Step 7.
NO Replace the G and yaw rate sensor. Service and Repair). Then go to Step 8.
STEP 7. Check whether the DTC is reset.

Q. Is DTC No. C1242 set?

YES Replace the AWC-ECU. (Refer to Twin Clutch-Sportronic Shift Transmission (TC-SST)). Then go to Step 8.
NO Intermittent malfunction. How to Cope With Intermittent Malfunctions).
STEP 8. Check whether the DTC is reset.

Q. Is DTC No. C1242 set?

YES Return to Step 1.
NO This diagnosis is complete.