B1731

DTC B1731: Communication error with the powertrain control module

CAUTION:
- If DTC B1731 is set in the ETACS-ECU, diagnose the CAN bus lines.
- Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.

DTC SET CONDITION
If the ETACS-ECU cannot receive the signal from the powertrain control module, DTC B1731 will be set.

TECHNICAL DESCRIPTION (COMMENT)
If a data error is detected in the powertrain control module, DTC B1731 will be set.

TROUBLESHOOTING HINTS
- Damaged wiring harness or connector
- Malfunction of powertrain control module
- Malfunction of the ETACS-ECU

DIAGNOSIS

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

STEP 1. 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 : Go to Step 2.

NO : Repair the CAN bus lines.

STEP 2. Recheck for diagnostic trouble code.

Recheck if the diagnostic trouble code is set.







1. Turn the ignition switch to "ON" position.
2. Erase the diagnostic trouble code.
3. Turn the ignition switch to the "LOCK" (OFF) position.
4. Turn the ignition switch to "ON" position.
5. Check if the diagnostic trouble code is set.
6. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC B1731 set?

YES : Replace the ETACS-ECU and register the ID codes. After registering the ID codes, go to Step 3.

NO : The procedure is complete.

STEP 3. Recheck for diagnostic trouble code.

Recheck if the diagnostic trouble code is set.







1. Turn the ignition switch to "ON" position.
2. Erase the diagnostic trouble code.
3. Turn the ignition switch to the "LOCK" (OFF) position.
4. Turn the ignition switch to "ON" position.
5. Check if the diagnostic trouble code is set.
6. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC B1731 set?

YES : Replace the powertrain control module and resister the ID code. Retest the system.

NO : The procedure is complete.