S-AWC

DTC U1003: Bas-off (Local CAN)

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 communicates with ASC-ECU and G and yaw rate sensor via the local CAN.

DTC SET CONDITIONS
The code is set when local CAN ceases (bus-off).

PROBABLE CAUSES
^ Malfunction of the CAN bus line (local)
^ 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 2.
NO: Repair the CAN bus lines.

STEP 2. Scan tool diagnostic trouble code
Check the ASC diagnostic trouble code. Diagnostic Trouble Code Descriptions
Q: The diagnostic trouble code is set.
YES: Perform the relevant troubleshooting.
NO: Go to Step 3.

STEP 3. 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 4.
NO: Repair the defective connector. Then go to Step 7.

STEP 4. 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 5.
NO: Repair the wiring harness. Then go to Step 7.

STEP 5. 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 6.
NO: Replace the G and yaw rate sensor. Then go to Step 6.

STEP 6. Check whether the diagnostic trouble code is reset.
Q: Is DTC No. U1003 set?
YES: Replace the AWC-ECU. Then go to Step 7.
NO: Intermittent malfunction.

STEP 7. Check whether the DTC is reset.
Q: Is DTC No. U1003 set?
YES: Return to Step 1.
NO: This diagnosis is complete.