S-AWC (Super All Wheel Control)

DTC C1242: G and Yaw Rate Sensor (Longitudinal G Output Data Error)

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 G and Yaw Rate Sensor Calibration ), and initialize the lateral/longitudinal acceleration correction amount stored in AWC-ECU. (Refer to item No.2: Lateral acceleration correction amount initialization, and No.3: Longitudinal acceleration correction amount initialization Actuator Test Reference Table .)

OPERATION

The G and yaw rate sensor outputs the signal to ASC-ECU and AWC-ECU via the special CAN bus lines.

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 DTC set?

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

Q. Is DTC No. C2204 set?

YES Perform the relevant troubleshooting.
NO Go to Step 5.
STEP 5. Scan tool diagnostic trouble code

Check if the local CAN communication-related, 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 6.
STEP 6. 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 7.
NO Reinstall the G and yaw rate sensor correctly. Then go to Step 7.
STEP 7. Scan tool service data

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

Q. Is the check result normal?

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

Q. Is DTC No. C1242 set?

YES Replace the AWC-ECU.(Refer to Active Center Differential (ACD).) Then go to Step 9.
NO Intermittent malfunction. How to Cope With Intermittent Malfunctions.)
STEP 9. Check whether the DTC is reset.

Q. Is DTC No. C1242 set?

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