U0024

DTC U0020: CAN-B Bus Off Performance

DTC U0021: CAN-B Bus (HI) Circuit Open

DTC U0022: CAN-B Bus (HI) Shorted to Circuit Ground

DTC U0023: CAN-B Bus (HI) Shorted to Circuit Power Supply

DTC U0024: CAN-B Bus (LO) Circuit Open

DTC U0025: CAN-B Bus (LO) Shorted to Circuit Ground

DTC U0026: CAN-B Bus (LO) Shorted to Circuit Power Supply

CAUTION:
- If the DTC U0020, U0021, U0022, U0023, U0024, U0025, U0026 is set in the occupant classification-ECU, always diagnose the CAN main bus lines.
- When replacing the ECU, always check that the communication circuit is normal.

DIAGNOSTIC FUNCTION

If the CAN-B circuit malfunction is present, the occupant classification-ECU sets the DTC U0020, U0021, U0022, U0023, U0024, U0025, U0026.

JUDGEMENT CRITERIA

Because of the CAN-B bus circuit malfunction, if occupant classification-ECU becomes unable to perform the normal data transmission, occupant classification-ECU determines that an abnormality is present.

TROUBLESHOOTING HINTS

The CAN bus line may be defective

DIAGNOSIS

Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicles Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)

STEP 1. Recheck for diagnostic trouble code
Check again if the DTC is set to the occupant classification-ECU.







CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958. Refer to "How to connect the scan tool". How To Connect The Scan Tool (M.U.T.-III)
2. Turn the ignition switch to the "ON" position.
3. Check if DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES: Go to Step 2.

NO: There is an intermittent malfunction such as poor engaged connector(s) or open circuit.

STEP 2. Using scan tool MB991958, diagnose the CAN bus line.

1. Turn the ignition switch to the "ON" position.
2. Diagnose the CAN bus line.
3. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the CAN bus line found to be normal?

YES: There is an intermittent malfunction such as poor engaged connector(s) or open circuit.

NO: Repair the CAN bus line.