DTC B1212/12: No Communication From Passenger's Front Door Ecu & Body Ecu

Verify passenger's front door power window AUTO up operates properly. If passenger's front door power window AUTO up operation is normal and vehicle is equipped with sun roof, go to next step. If passenger's front door power window AUTO up operation is normal and vehicle is not equipped with sun roof, go to step 3. If passenger's front door power window AUTO up operation is not normal, replace passenger's front door ECU.
Disconnect 10-pin sun roof control relay connector. SeeFig 1. Disconnect 18-pin passenger's front door ECU connector "A". See Figure. Disconnect 25-pin right rear door ECU connector "A". See Figure. Check for continuity in Yellow wire between passenger's front door ECU connector "A" terminal No. 9 (MPX1) and sun roof control relay connector terminal No. 1 (BUS1). Also, check for continuity in Yellow wire between passenger's front door ECU connector "A" terminal No. 18 (MPX2) and right rear door ECU connector "A" terminal No. 4 (MPX2). If continuity does not exist in all measurements, repair or replace wiring harness or connectors. See WIRING DIAGRAMS . If continuity exists in all measurements, replace passenger's front door ECU.
Disconnect 22-pin tilt and telescopic ECU connector "B". See Fig 2. Disconnect 18-pin passenger's front door ECU connector "A". See Figure. Disconnect 25-pin right rear door ECU connector "A". See Figure. Check for continuity in Yellow wire between passenger's front door ECU connector "A" terminal No. 9 (MPX1) and tilt and telescopic ECU connector "B" terminal No. 2 (MPX2). Also, check for continuity in Yellow wire between passenger's front door ECU connector "A" terminal No. 18 (MPX2) and right rear door ECU connector "A" terminal No. 4 (MPX2). If continuity does not exist in all measurements, repair or replace wiring harness or connectors. See WIRING DIAGRAMS . If continuity exists in all measurements, replace passenger's front door ECU.

Fig 1: Identifying Sun Roof Control Relay Connector & Terminals

Fig 2: Identifying Tilt & Telescopic ECU Connectors & Terminals