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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 DTC 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.
  • When hydraulic unit (integrated with G and yaw rate sensor) is replaced, calibrate G and yaw rate sensor (Refer to GROUP 35C - On-vehicle Service ).
 
 
OPERATION
AWC-ECU receives the G and yaw rate sensor data from ASC-ECU via the CAN communication.
 
 
DTC SET CONDITIONS
This DTC is set when the abnormality below is detected:
  • Abnormality in G and yaw rate sensor output value
  • The abnormality is detected by comparing the longitudinal G-sensor value output from the G and yaw rate sensor with the value output from the wheel speed sensor.
 
 
PROBABLE CAUSES
  • Hydraulic unit (incorporating G and yaw rate sensor) improperly installed
  • Improper installation of G and yaw rate sensor
  • Malfunction of wheel speed sensor
  • Malfunction of stoplight switch
  • Malfunction of stoplight switch circuit system
  • Malfunction of AWC-ECU

 
 
DIAGNOSIS
STEP 1. Scan tool (M.U.T.-IIISE) CAN bus diagnostics.
Use scan tool (M.U.T.-IIISE) to perform the CAN bus diagnosis.
Is the check result normal?
Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C - Diagnosis, Can Bus Diagnostics Table ).
 
STEP 2. Scan tool (M.U.T.-IIISE) other system DTC.
Check the ASC DTC (Refer to GROUP 35C - Diagnosis, Diagnostic Trouble Code Chart ).
Is the DTC set?
Perform the relevant troubleshooting.
Go to Step 3.
 
STEP 3. Scan tool (M.U.T.-IIISE) other system DTC.
Check if the wheel speed sensor-related DTC is set.
Is the DTC set?
Perform the relevant troubleshooting.
Go to Step 4.
 
STEP 4. Check of hydraulic unit (integrated with G and yaw rate sensor) installation status.
Check that the hydraulic unit (integrated with G and yaw rate sensor) is installed correctly (Refer to GROUP 35C - Hydraulic unit (integrated with G and yaw rate sensor) ).
Is the check result normal?
Go to Step 5.
Reinstall the hydraulic unit (integrated with G and yaw rate sensor) correctly. Then go to Step 5.
 
STEP 5. Scan tool (M.U.T.-IIISE) data list.
Check the following data list (Refer to ).
  • Item No.41: Longitudinal G
Is the check result normal?
Go to Step 6.
Replace the hydraulic unit (integrated with G and yaw rate sensor) (Refer to GROUP 35C - Hydraulic unit (integrated with G and yaw rate sensor) ).
 
STEP 6. Check whether the DTC is set again.
Is DTC C1242 set?
Replace the AWC-ECU (Refer to ).
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).