B1321

DTC B1321 Comm. error (DR P/W ECU)






CIRCUIT OPERATION

During convertible top operation, the convertible top control module communicates with the power window motor (LH) to lower the front window glass. When the convertible top is not operating, it drives the quarter window glass according to the signal from the power window motor (LH).

DTC SET CONDITION

This DTC is set when an error occurs in the communication between the convertible top control module and the power window motor (LH).

TROUBLESHOOTING HINTS

- Malfunction of the power window motor (LH)
- Damaged harness wires and connectors
- Malfunction of the convertible top control module

DIAGNOSIS

Required Special Tool

- 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
- MB992006: Extra fine probe

STEP 1. Check convertible top control module connector D-45 and power window motor (LH) connector E-16 for loose, corroded or damaged terminals, or terminals pushed back in the connector.









Q. Is the check result satisfactory?

YES Go to Step 2.

NO Repair or replace the damaged component(s).

STEP 2. Check the harness between power window motor (LH) connector E-16 (terminal 7, 3) and convertible top control module connector D-45 (terminal 31, 32).









- Check for power supply and short circuit of the relevant harness.

NOTE:
Before the wiring harness check, check the intermediate connectors C-25 and C-23, and repair if necessary.

Q. Is the check result satisfactory?

YES Replace the power window motor (LH). Then go to Step 3.

NO Repair the harness wire.

STEP 3. Recheck the DTC.

Q. Is DTC B1321 set?

YES Replace the convertible top control module.
NO Intermittent malfunction How to Cope With Intermittent Malfunctions).