C1618

DTC C1618: AWC CAN Local Data System (data not received)

G AND YAW RATE SENSOR POWER SUPPLY
S-AWC

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 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 Special Function Reference Table)

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

DTC SET CONDITIONS
The code is set when the signal necessary for AWC control cannot be received.

PROBABLE CAUSES
^ The CAN bus line is defective.
^ Malfunction of local CAN bus line
^ Malfunction of ASC-ECU
^ Malfunction of G and yaw rate sensor
^ Malfunction of AWC-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. After repairing the CAN bus line, go to Step 2.

STEP 2. Check whether the DTC is reset.
Q: Is DTC No. C1618 set?
YES: Go to Step 3.
NO: This diagnosis is complete.

STEP 3. Scan tool diagnostic trouble code
Check if the AWC diagnostic trouble code No. U1003 is set.(Diagnostic Trouble Code Descriptions)
Q: Is the DTC set?
YES: Perform the relevant troubleshooting.
NO: Go to Step 4.

STEP 4. Scan tool diagnostic trouble code
Check the ASC diagnostic trouble code. Diagnostic Trouble Code Descriptions
Q: Is the DTC set?
YES: Perform the relevant troubleshooting.
NO: Go to Step 5.

STEP 5. ASC-ECU connector, G and yaw rate sensor connector, AWC-ECU connector, intermediate connector, J/C (7) check: A-05, C-38, C-46, C-47, C-50
Q: Is the check result normal?
YES: Go to Step 6.
NO: Repair the defective connector. Then go to Step 10.

STEP 6. Check the wiring harness between C-46 AWC-ECU connector terminal No. 9, 10 and C-38 G and yaw rate sensor connector terminal No. 2, 3, and between C-46 AWC-ECU connector terminal No. 9, 10 and A-05 ASC-ECU connector terminal No. 18, 19.
Check the wiring harness for open and short circuit (to ground, to power supply, or line-to line).
Q: Is the check result normal?
YES: Go to Step 7.
NO: Repair the wiring harness. Then go to Step 9.

STEP 7. Scan tool service data
Check the following service data. (Data List Reference Table)
^ Item No. 26: Yaw rate sensor
^ Item No. 29: Lateral G sensor
^ Item No. 31: Longitudinal G sensor
Q: Is the check result normal?
YES: Go to Step 9.
NO: Go to Step 8.

STEP 8. Check the wiring harness between A-05 ASC-ECU connector terminal No. 22 and C-38 G and yaw rate sensor connector terminal No. 1, and between A-05 ASC-ECU connector terminal No. 29 and C-38 G and yaw rate sensor connector terminal No. 5.
Check the wiring harness for open or short circuit (short to ground).
Q: Is the check result normal?
YES: Replace the G and yaw rate sensor. Then go to Step 9.
NO: Repair the wiring harness. Then go to Step 10.

STEP 9. Check whether the DTC is reset.
Q: Is DTC No. C1618 set?
YES: Replace the AWC-ECU. Then go to Step 10.
NO: Intermittent malfunction.

STEP 10. Check whether the DTC is reset.
Q: Is DTC No. C1618 set?
YES: Return to Step 1.
NO: This diagnosis is complete.