B2240

DTC B2240: Communication error between CAN box unit and navigation unit

CAN Box Unit Communication Circuit (Part 1):

CAN Box Unit Communication Circuit (Part 2):

TROUBLE JUDGMENT
When the abnormality Occurs in the transmission/reception data between the CAN box unit and audio visual navigation unit, the CAN box unit sets DTC B2240.

PROBABLE CAUSES
- Audio visual navigation unit malfunction
- CAN box unit malfunction
- Damaged wiring harness and connectors

DIAGNOSIS

Required Special Tools:
- MB991958 Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle 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)
- MB991223: Harness Set
- MB992006: Extra Fine Probe

STEP 1. Perform "Network/Connect Line Check" of the MMCS service mode.

Perform "Network/Connect Line Check" of the MMCS service mode, and check that the communication between the CAN box unit and the audio visual navigation unit is normal. Service Mode

NOTE: When the communication between the CAN box unit and the audio visual navigation unit is normal, "CAN BOX" is displayed on the check result screen. However, if the communication is not possible, "CAN BOX" is not displayed.

Q: Is "CAN BOX" displayed?

YES : Go to Step 2.

NO : Go to Step 3.

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

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 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.

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

YES : Intermittent malfunction is suspected. Refer to general (Body and Chassis), How to Use Troubleshooting/Inspection Service Points How to Cope with Intermittent Malfunction

NO : Repair the CAN bus line. (Refer to Controller area network Diagnosis).

STEP 3. Check CAN box unit connector C-108 and audio visual navigation unit connector C-12 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are CAN box unit connector C-108 and audio visual navigation unit connector C-12 in good condition?

YES : Go to Step 4.

NO : Repair or replace the damaged component(s). Refer to general (electrical), Harness Connector Inspection. The steering remote control switch should work normally.

STEP 4. Check the wiring harness between CAN box unit connector C-108 (terminal 4, 5, 6) and audio visual navigation unit connector C-12 (terminal 43, 59, 58).

Q: Is the wiring harness between CAN box unit connector C-108 (terminal 4, 5, 6) and audio visual navigation unit connector C-12 (terminal 43, 59, 58) in good condition?

YES : Go to Step 5.

NO : The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.

STEP 5. Substitute a known good CAN box unit, and check the trouble symptom.

Check whether scan tool MB991958 with CAN box unit normally.

Q: Is the check result normal?

YES : Replace the CAN box unit.

NO : Replace the audio visual navigation unit.