Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / U049A — Invalid Data Received From Door Control Module A

U049A — Invalid Data Received From Door Control Module A

Detailed page for trouble code U049A.

32,893codes
59brands
10,435generic
22,458specific
All codes P-codes (Powertrain) B-codes (Body) C-codes (Chassis) U-codes (Network/User) Tesla Alerts
Reset
Code

U049A

Generic U — Network/User

Invalid Data Received From Door Control Module A

Brand: Generic
Type: U — Network/User
Views: UK: 16 EN: 33 RU: 19
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Faulty Door Control Module A (hardware or corrupted firmware)
  • Damaged wiring, connectors, or pins between DCM A and vehicle network
  • Poor or intermittent module ground or supply voltage
  • CAN bus physical-layer problem (short, open, missing termination)
  • Software/configuration mismatch or missing module coding/calibration
  • Interference or multiple modules using same node ID (address conflict)

Symptoms

  • One or more door-related features fail or behave erratically (locks, windows, mirror folding, courtesy lights)
  • Multiple communication-related DTCs present (other modules report DCM A errors)
  • Intermittent operation of remote/keyless entry
  • CAN bus warnings or bus-off conditions logged
  • Possible blown fuses or parasitic battery drain if wiring short exists

What to check

  • Read all modules with a capable scan tool; record U-codes and freeze frame data
  • Check for related codes (other U0xxx or B/C/P codes) that indicate broader network issues
  • Visually inspect door harness, module connector, and pins for corrosion, bent pins, or water damage
  • Verify vehicle battery voltage and measure module supply (ignition on and cranking)
  • Measure module ground integrity (low resistance to chassis) and check for intermittent connections
  • Measure CAN bus resistance across CAN_H and CAN_L (expected ~60 ohms total) and inspect for opens/shorts

Signal parameters

  • Typical CAN baud rates: 250 kbps or 500 kbps (verify vehicle-specific rate with scan tool)
  • Expected periodic messages from a door module commonly in the 1–20 Hz range (check live data for expected signals and update rate)
  • Physical layer: CAN_H and CAN_L idle voltages ≈ 2.5 V each; dominant state typically produces ~2 V differential (verify with scope)
  • Termination: two 120 ohm resistors in parallel ≈ 60 ohms across CAN_H and CAN_L at vehicle harness ends
  • Message format: standard CAN data frames (check for malformed DLC, unexpected arbitration ID, or corrupted payload)

Diagnostic algorithm

  1. Connect professional scan tool and note all stored/active U-codes and freeze frame; attempt to clear codes and reproduce; note persistence.
  2. Confirm battery health and stable supply voltage; perform tests with battery fully charged to avoid false communication errors.
  3. Inspect DCM A connector and wiring at the door and at any intermediate junctions; repair damaged wiring or corroded terminals.
  4. Verify power and ground at the door control module with a multimeter; wiggle wiring while monitoring for voltage drop or code set.
  5. Check CAN bus integrity: measure termination resistance (~60 Ω) and use an oscilloscope to view CAN_H/CAN_L waveforms for noise, reflections, or missing recessive/dominant states.
  6. Monitor messages from DCM A with the scan tool or a CAN logger: verify expected arbitration ID, data length, payload consistency, and periodicity. Look for malformed frames or CRC failures.
  7. Isolate the door module from the bus (if vehicle design allows) or disconnect other aftermarket modules to see if code clears; this helps identify network conflicts.
  8. If wiring and bus are good, check module software/coding and update or reflash per OEM procedures; follow correct programming steps when replacing a module.
  9. Replace the door control module only after confirming wiring, power/ground, and bus are healthy; after replacement, program/configure module and re-test.

Likely causes

  • Loose or corroded connector at the door control module
  • Water intrusion or mechanical damage to door harness
  • Failed microcontroller or memory corruption in DCM A
  • Broken shield or short to battery/ground on CAN pair in door harness
  • Module not programmed or wrong software version after replacement

Fault status

⚠️ Status
Control module A (door control) is sending invalid or corrupted network data. Communications between the door module and vehicle network are degraded or failing.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours

Similar codes

U0100 U0121 U0155 U1301 U0073 U0401
Workshop Manuals

Available brands with manuals

2
AUDI 11

6-speed manual gearbox 0B1, front-wheel drive — Workshop Manual (Edition 05.2014)

Workshop Manual
Years: 2008 Manual in English Pages: 187 4.9 MB
Short description

Workshop manual for the 6‑speed manual gearbox 0B1 (front‑wheel drive). Includes identification, technical data, gearbox/selector removal & installation procedures, clutch hydraulics, adjustment instructions and front differential service. Applicable to Audi A4, Audi A5 (Coupé, Cabriolet, Sportback) and Audi Q5 as referenced in the manual. Edition: 05.2014.

Contents
Key sections:
  • 00 - Technical data
  • 1 Identification
  • 1.1 Gearbox identification
  • 2 Technical data
  • 2.1 Allocation of gearbox to engine
  • 2.1.1 Allocation - Audi A4 2008 ►
  • 2.1.2 Allocation - Audi A5 Coupé 2008 ►, Audi A5 Sportback 2010 ►
  • 2.1.3 Allocation - Audi A5 Cabriolet 2009 ►
  • 2.1.4 Allocation - Audi Q5 2008 ►
  • 2.2 Capacities
  • 3 Transmission layout
  • 3.1 Transmission layout - front‑wheel drive
Download

Audi A3 (1997) – 1.6L 4-cylinder (2‑valve) Engine Mechanical Components Service Manual (AEH, AKL, APF) – Edition 07.2002

Workshop Manual
Years: 1997 Manual in English Pages: 283 4.3 MB
Short description

Service manual for Audi A3 (1997) 1.6L 4‑cylinder (2‑valve) engines (codes AEH, AKL, APF). Includes technical data, engine removal/installation, crankshaft group, cylinder head and valve gear, lubrication, cooling and exhaust system procedures. Edition 07.2002.

Contents
Key sections:
  • 00 - Technical data ............................................................1
  • 1 Technical data ............................................................1
  • 1.1 Technical data .......................................................1
  • 1.2 Engine number .......................................................1
  • 1.3 Engine data ........................................................1
  • 10 - Removing and installing engine ..........................................3
  • 1 Removing and installing engine .........................................3
  • 1.1 Removing and installing engine ....................................3
  • 1.2 Removing - vehicles with engine codes AEH, AKL .....................4
  • 1.3 Removing - vehicles with engine code APF ..........................18
  • 1.4 Detaching engine from gearbox ...................................35
  • 1.5 Attaching engine to repair stand ................................38
Download

AUDI A3 (2004) Workshop Manual — 2.0L FSI Turbo (4‑cyl, 4‑valve) Engine, Mechanics — Edition 03.2017

Workshop Manual
Years: 2004 Manual in English Pages: 235 3.8 MB
Short description

Official workshop manual for the Audi A3 2.0L FSI turbo engine (mechanics). Includes step‑by‑step removal/install procedures, technical data, tightening torques and diagnostic/repair instructions. Intended for professional garages and experienced technicians.

Contents
Key sections:
  • 00 - Technical data
  • 1 Engine number
  • 2 Engine data (code letters AXX, BPY, BWA, BHZ, BZC, CDL — capacity, power, torque, bore/stroke, compression, ignition)
  • 3 Safety precautions
  • 3.1 Working on the fuel system
  • 3.2 Procedure before opening high-pressure section
  • 3.3 Working on the cooling system
  • 3.4 Using testers during road test
  • 3.5 Working on the exhaust system
  • 4 General repair instructions
  • 4.1 Cleanliness rules for fuel/injection/turbo
  • 4.2 Checking fuel system for leaks
Download

Audi A3 2004 — Electrical System (Workshop Manual, Edition 02.2018)

Workshop Manual
Years: 2004 Manual in English Pages: 150 68.2 MB
Short description

Workshop manual for the Audi A3 (2004) — Electrical system. Includes procedures for battery, starter, alternator, gauges, wipers, exterior/interior lighting and wiring. Edition 02.2018.

Contents
Key sections:
  • List of Workshop Manual Repair Groups
  • - 27 Starter, current supply, CCS
  • - 90 Gauges, instruments
  • - 92 Windscreen wash/wipe system
  • - 94 Lights, bulbs, switches - exterior
  • - 96 Lights, bulbs, switches - interior
  • - 97 Wiring
  • 27 - Starter, current supply, CCS
  • 1 Contact corrosion
  • 2 Battery
  • 2.1 Battery - general notes
  • 2.2 Maintenance-free batteries
Download

Audi A4 / A4 Cabriolet – 4.2 l V8 (5‑valve, timing chains) – Workshop Manual (Mechanics) – Edition 04.2007

Workshop Manual
Years: 2001–2003 Manual in English Pages: 307 7.3 MB
Short description

Comprehensive workshop manual for Audi A4 (2001) and A4 Cabriolet (2003) with the 4.2 L V8, 5‑valve engine with timing chains (Engine IDs BBK/BHF). Includes step‑by‑step procedures for engine removal/installation, crankshaft and timing chain service, cylinder head/valve gear, lubrication, cooling and exhaust system repairs. Intended for professional technicians and service workshops.

Contents
Key sections:
  • 00 - Technical data
  • 1 Engine number
  • 2 Engine data (Codes: BBK / BHF; 4.163 l; 253 kW @7000 rpm; torque 410–420 Nm; bore 84.5 mm; stroke 92.8 mm; compression ratio 11.5; RON 98)
  • 3 Safety precautions
  • 4 General repair instructions (cleanliness, fuel system, contact corrosion)
  • 10 - Removing and installing engine
  • 1 Removing engine - vehicles with manual gearbox
  • 1.1 Removing engine (tools, drain fluids, remove bumper, lock carrier, disconnect wiring, fuel, coolant, A/C lines, suspension components, propshaft, exhaust, support engine on platform, lower assembly)
  • 1.2 Separating engine and gearbox (subframe removal, support sets, remove front exhaust pipes, bolt sequence)
  • 1.3 Securing engine to engine and gearbox stand (lifting tackle, VAS 6095 support)
  • 1.4 Installing engine (clutch remarks, alignment, torque values)
  • 2 Removing and installing engine - vehicles with automatic gearbox (procedure parallels manual gearbox with ATF/torque converter notes)
Download

Audi A4 / A4 Cabriolet — Auxiliary Heater Workshop Manual (Edition 08.2004)

Workshop Manual
Years: 2001 Manual in English Pages: 259 2.0 MB
Short description

Workshop Manual for Audi A4 and A4 Cabriolet — Auxiliary Heater (Edition 08.2004). Contains self-diagnosis procedures, fault tables, electrical and fuel system checks, final control tests, CO₂ exhaust adjustment and step-by-step removal/installation and repair procedures. Intended for professional workshop use.

Contents
Key sections:
  • 01 - Self-diagnosis, electrical checks
  • 1 Auxiliary heater self-diagnosis
  • 1.1 Technical data of self-diagnosis
  • 1.2 Function
  • 1.3 Fault recognition
  • 1.4 Guided fault-finding
  • 1.5 Technical data of self-diagnosis
  • 1.6 Test requirements for self-diagnosis
  • 1.7 Safety precautions
  • 2 Self-diagnosis procedure
  • 2.1 Connecting vehicle diagnostic VAS 5051A/K-wire adapter
  • 2.1.1 Control unit identification
Download

Audi A4 / A4 Cabriolet (1.8T 4‑cyl turbo) — Motronic Injection & Ignition System Service Manual (Edition 01.2015)

Workshop Manual
Years: 2001 Manual in English Pages: 34 851.0 KB
Short description

Service manual for Audi A4 (2001‑) and A4 Cabriolet (2003‑) with 1.8L 4‑cylinder turbo engines. Covers Motronic fuel injection and ignition systems, diagnostic and maintenance procedures. Includes technical data, removal/installation steps and system checks.

Contents
Key sections:
  • 24 - Mixture preparation - injection
  • 1 Safety precautions and rules for cleanliness
  • 1.1 General notes on self-diagnosis
  • 1.2 Safety precautions when using testers and measuring instruments during a road test
  • 1.3 Rules for cleanliness and instructions for working on fuel system
  • 1.4 Checking vacuum system
  • 2 Injection system
  • 2.1 Technical data
  • 2.2 Overview of fitting locations - injection system
  • 3 Intake manifold
  • 3.1 Exploded view - intake manifold
  • 3.2 Removing and installing intake manifold
Download

Audi A8 (2003) — Electrical System Workshop Manual (Edition 08.2014)

Workshop Manual
Years: 2003 Manual in English Pages: 369 9.1 MB
Short description

Comprehensive workshop manual for the Audi A8 (2003) electrical system — Edition 08.2014. Covers battery, alternator, starter, instrument cluster, wiper/washer systems, exterior/interior lighting and wiring repair procedures with step-by-step illustrations. Includes diagnostic and adjustment procedures and torque/data specifications.

Contents
Key sections:
  • 27 - Starter, current supply, CCS
  • 1 Contact corrosion
  • 2 Battery
  • 2.1 Battery - general notes
  • 2.2 Maintenance-free batteries
  • 2.3 Disconnecting and connecting battery
  • 2.4 Removing and installing battery
  • - Remove luggage compartment side trim (right-side)
  • - Connect battery charger for back-up power
  • - Detach earth and positive cables, central venting hose
  • - Remove battery retainer plate and lift battery out
  • - Installation notes, adaptation via Vehicle diagnostic tester
Download

Audi Q4 e-tron (Type F4) - Self-study Programme SSP 685

Workshop Manual
Years: 2021 Manual in English Pages: 186 82.7 MB
Short description

Official Audi Service Training self‑study programme SSP 685 for the Audi Q4 e‑tron (Type F4). Covers body, power units, power transmission, running gear, electrics & electronics, high‑voltage system, thermal management, driver assist and infotainment. Intended for internal service training and technical familiarisation; not a workshop repair manual.

Contents
Key sections:
  • Introduction
  • - Introduction to Audi Q4 e-tron
  • - Dimensions
  • Body
  • - Body structure and materials
  • - Joining techniques
  • - Securing high-voltage battery and force progression
  • - Body assembly (doors, rear lid, panoramic sunroof)
  • - Dash panel and centre console
  • Power units
  • - Technical data: rear electric motor (VX90)
  • - Technical data: front electric motor (VX89)
Download

Audi Q8 (2018) — Electrical System Workshop Manual (Edition 05.2019)

Workshop Manual
Years: 2018 Manual in English Pages: 645 14.8 MB
Short description

Workshop manual for the Audi Q8 (2018) — Electrical System. Includes technical data, safety notes and step‑by‑step repair procedures for battery/charging, starter/alternator, lighting, washer/wiper and wiring. Edition 05.2019.

Contents
Key sections:
  • 00 - Technical data
  • 1 Safety precautions
  • 1.1 Safety precautions when working on vehicles with start/stop system
  • 1.2 Safety precautions when using testers and measuring instruments during a road test
  • 1.3 Notes on use and safety for LED headlights and Audi laser lights
  • 2 Repair notes
  • 2.1 Rules for cleanliness
  • 2.2 General notes
  • 2.3 Contact corrosion
  • 2.4 ESD (electrostatic discharge) workplace
  • 2.5 Routing and attachment of lines and wiring
  • 2.6 Identification plates
Download

Audi Servicing Manual — 7‑Speed Dual Clutch Transmission 0CJ / 0CL / 0CK / 0DN / 0DP / 0HL (Edition 05.2018)

Workshop Manual
Years: 2008–2019 Manual in English Pages: 128 11.1 MB
Short description

Service manual for the 7‑Speed dual‑clutch (DSG) transmissions 0CJ/0CL/0CK/0DN/0DP/0HL fitted to various Audi models. Includes repair information, clutch and gearbox disassembly/assembly, mechatronic and hydraulic system procedures, seals and differential work. Edition 05.2018.

Contents
Key sections:
  • 00 - General, Technical Data
  • 1 Repair Information
  • 1.1 General Repair Information
  • 1.2 Contact Corrosion
  • 1.3 ATF Pump, Deactivating and Draining the Hydraulic Pump Reservoir
  • 2 Rules for Cleanliness when Working on DSG® Transmission
  • 30 - Clutch
  • 1 Clutch
  • 1.1 Overview - Flywheel and Dual Clutch
  • 1.2 Flywheel, Removing and Installing
  • 1.3 Dual Clutch, Removing and Installing
  • 1.4 Input Shaft Seal, Replacing
Download
LAND ROVER 3

Land Rover Defender 300Tdi — Workshop Manual (1996 model year)

Workshop Manual
Defender 300Tdi Years: 1996 Manual in English 7.5 MB
Short description

Official workshop manual for the Land Rover Defender 300Tdi (from 1996 model year). Contains specifications, adjustment, fault diagnosis and step-by-step repair and overhaul procedures for engine, transmission, axles, suspension, brakes, electrical and body. Intended for dealer workshops and trained technicians.

Contents
Key sections:
  • 01 INTRODUCTION
  • 04 GENERAL SPECIFICATION DATA
  • 05 ENGINE TUNING DATA
  • 07 GENERAL FITTING REMINDERS
  • 09 LUBRICANTS, FLUIDS AND CAPACITIES
  • 10 MAINTENANCE
  • 12 ENGINE Tdi
  • - Description and operation
  • - Fault diagnosis
  • - Adjustment
  • - Repair and overhaul procedures
  • 19 FUEL SYSTEM Tdi
Download

Land Rover Defender Workshop Manual Supplement & Body Repair Manual (1999 & 2002 MY)

Workshop Manual
Defender Years: 1999–2002 Manual in English 7.6 MB
Short description

Workshop Manual Supplement and Body Repair Manual for the Land Rover Defender. Includes general specifications, maintenance schedules, tuning data and step‑by‑step repair procedures for engine, transmission, suspension, brakes, electrical and body repairs. Covers Defender models from 1999 and 2002 model years.

Contents
Key sections:
  • 01 - INTRODUCTION
  • - Introduction
  • - Dimensions
  • - References
  • - Repairs and replacements
  • - Poisonous substances
  • - Fuel handling precautions
  • - Synthetic rubber
  • - Recommended sealants
  • - Used engine oil precautions
  • - Accessories and conversions
  • - Wheels and tyres
Download

Land Rover Range Rover — Electrical Library (LRL 0453ENG, 2002)

Workshop Manual
Manual in English Pages: 494 7.1 MB
Short description

Land Rover Range Rover Electrical Library (LRL 0453ENG). Comprehensive manual covering fuse details, earth points, system descriptions, diagnostics and connector pin-outs for electrical troubleshooting and repair. Intended for technicians and service workshops.

Contents
Key sections:
  • 1 INTRODUCTION
  • 1.1 About this document
  • 1.2 Battery voltage
  • 1.3 Electrical precautions
  • 1.4 Battery disconnecting / charging
  • 1.5 Disciplines / greases
  • 1.6 Abbreviations
  • 1.7 HeVAC, sensors abbreviations
  • 1.8 How to use this document
  • 1.9 Connector detail format
  • 1.10 Fault diagnosis
  • 1.11 Wire colour codes
Download
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email

Report

Harassment or bullying behavior
Contains mature or sensitive content
Contains misleading or false information
Contains abusive or derogatory content
Contains spam, fake content or potential malware

Block Member?

Please confirm you want to block this member.

You will no longer be able to:

  • See blocked member's posts
  • Mention this member in posts
  • Invite this member to groups
  • Message this member
  • Add this member as a connection

Please note: This action will also remove this member from your connections and send a report to the site admin. Please allow a few minutes for this process to complete.

Report

You have already reported this .