Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2003 Acura MDX BaseFACTORY OEM SERVICE PROCEDURE
Section 58 (Multiplex Integrated Control System)
WARNING: This page is about a different car, the 2009 Acura MDX, 2008 Acura MDX, and 2007 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.
- Component Location Index
- General Troubleshooting Information
- DTC Troubleshooting Index
- System Description
- MICU Control Functions
- Gateway Function
- Network "Loss of Communication" Error Checking Function
- Notes
- Self-diagnostic Function
- Wake-up and Sleep Function
- Fail-safe Function
- Hardware Fail-safe Control
- Software Fail-safe Control
- Power Supply Voltage Monitoring Function
- Entry Lights Control System (Ceiling Lights, Ignition Key Light)
- Back-up Lights
- Turn Signal/Hazard Warning Lights
- Collision Detection Signal (CDS)
- Automatic Lighting System
- Headlight Washer Operation
- Key Interlock
- Power Door Locks (Unlock all doors and tailgate at the same time)
- Power Door Locks (Unlock only the driver's door first)
- Door Lock Response Operation
- Keyless Entry System (Unlock all doors and tailgate at the same time)
- Keyless Entry System (Unlock only the driver's door first)
- Answer Back Response Operation
- Auto Power Door Locks (LOCK operation)
- Auto Power Door Locks (UNLOCK operation)
- Tailgate Outer Handle Switch Operation (Unlock all doors and tailgate at the same time)
- Tailgate Outer Handle Switch Operation (Unlock only the driver's door first)
- Security Alarm System
- Prevention of Key Locked Inside Vehicle
- HDS Inputs and Commands
- Troubleshooting - B-CAN System Diagnosis Test Mode A
- Troubleshooting - B-CAN System Diagnosis Test Mode B
- Troubleshooting - B-CAN System Diagnosis Test Mode C
- Troubleshooting - B-CAN System Diagnosis Test Mode D
- Troubleshooting - B-CAN System Diagnosis Test Mode 1 and Test Mode 2 (without the HDS)
- Sleep and Wake-up Mode Test
- Circuit Diagram
- DTC Troubleshooting
- DTC B1000: Communication Bus Line Error
- DTC B1001: MICU Internal (CPU) Error; DTC B1002: MICU Internal (EEPROM) Error
- DTC B1005: MICU Lost Communication with Relay Control Module (RM Message)
- DTC B1007: MICU Lost Communication with Combination Switch Control Unit (HLSW Message)
- DTC B1011: MICU Lost Communication with Gauge Control Module (VSP/NE Message)
- DTC B1012: MICU Lost Communication with Rear MICU (RJC Message)
- DTC B1013: MICU Lost Communication with Driver's MPCS Unit (ASLOCKSW Message); DTC B1015: MICU Lost Communication with Driver's MPCS Unit (DRLOCKSW Message)
- DTC B1032: MICU Lost Communication with the SRS Unit (CDS Message)
- DTC B1080: Ignition Key Switch Circuit Malfunction
- DTC B1050: Communication Bus Line Error; DTC B1150: Communication Bus Line Error; DTC B1200: Communication Bus Line Error; DTC B1250: Communication Bus Line Error; DTC B1350: Communication Bus Line Error; DTC B1750: Communication Bus Line Error; DTC B1800: Communication Bus Line Error; DTC B1900: Communication Bus Line Error; DTC B1950: Communication Bus Line Error; DTC B2150: Communication Bus Line Error; DTC B2200: Communication Bus Line Error
- DTC B2152: Driver's MPCS Unit Internal (EEPROM) Error
- DTC B2155: Driver's MPCS Unit Lost Communication with MICU (MICU Message); DTC B2156: Driver's MPCS Unit Lost Communication with MICU (MIRRORSW Message); DTC B2161: Driver's MPCS Unit Lost Communication with MICU (DOORSW Message)
- DTC B2157: Driver's MPCS Unit Lost Communication with Gauge Control Module (ILLUMI Message); DTC B2160: Driver's MPCS Unit Lost Communication with Gauge Control Module (VSP/NE Message)
- DTC B2162: Driver's MPCS Unit Lost Communication with Relay Control Module (RM Message)
- MICU Input Test
- Relay Control Module Input Test
- Driver's MPCS Unit Input Test
- Rear MICU Input Test
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.