Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / U0104 — Lost communication with the speed control module

U0104 — Lost communication with the speed control module

Detailed page for trouble code U0104.

32,982codes
59brands
10,521generic
22,461specific
All codes P-codes (Powertrain) B-codes (Body) C-codes (Chassis) U-codes (Network/User) Tesla Alerts
Reset
Code

U0104

LAND ROVER U — Network/User

Lost communication with the speed control module

Brand: LAND ROVER
Type: U — Network/User
Views: UK: 14 EN: 14 RU: 39
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Failed speed control (cruise control) module
  • Open or shorted CAN bus wiring between module and network
  • Poor power or ground to the speed control module (blown fuse, bad connector, corroded ground)
  • Missing or incorrect CAN bus termination (open/missing resistor)
  • Intermittent connector or pin damage at module or splice
  • Other module on the same network causing bus-off or bus errors

Symptoms

  • Cruise control inoperative or unavailable
  • Related warning lights on dash (e.g., ESC/ABS, cruise fault, master warning)
  • Speedometer or speed-related features may behave erratically
  • Multiple CAN or communication DTCs present
  • Possible limp-home modes or reduced function depending on system

What to check

  • Read all stored and pending DTCs with a dealer-level scan tool; note freeze frame and MIL status
  • Check battery voltage and terminals (must be healthy during diagnosis)
  • Inspect fuses and relays supplying the speed control module
  • Visually inspect wiring and connectors at the module for corrosion, bent pins, or damage
  • Check for other communication codes on the same CAN network
  • Measure CAN bus termination resistance (approx. 60 ohms across CAN H/L with key off)

Signal parameters

  • CAN bus differential signal: CAN_H ~ 2.5–3.5 V, CAN_L ~ 1.5–2.5 V when active (typical high-speed CAN levels)
  • Termination: approx. 60 ohms between CAN_H and CAN_L (two 120 ohm in parallel)
  • Common high-speed CAN data rates: 500 kbps (verify vehicle-specific rate from wiring diagram)
  • Key-on: module should respond to OBDII/diagnostic requests and broadcast periodic messages
  • No dominant bus-off condition (continuous recessive state or dominant stuck indicate faults)

Diagnostic algorithm

  1. Confirm U0104 presence and note whether it is current, pending, or history. Scan for other U-codes and related faults.
  2. Record freeze frame and attempt to reproduce: cycle ignition, start vehicle, and see if code returns.
  3. Verify vehicle battery voltage >= 12.4 V during diagnosis. Inspect and test fuses/relays feeding the speed control module.
  4. With ignition off, inspect the module connector for corrosion, water intrusion, pushed-out pins, or bent terminals. Repair as needed.
  5. Measure power and ground at the module connector with ignition on. Confirm proper voltage and low-resistance ground.
  6. Check CAN continuity between module connector and the nearest gateway or junction: verify no opens or shorts to battery/ground.
  7. Measure termination resistance across CAN_H and CAN_L at the module and another network node (~60 ohms).
  8. Use an oscilloscope or CAN analyzer with ignition on to view CAN_H/CAN_L waveforms while cranking/running. Look for valid differential frames and message traffic; identify if the module transmits.
  9. If another module is bus-off or causing errors, isolate/disconnect suspect modules one at a time and re-check bus health.
  10. If wiring and power/ground are good but the module does not communicate, consider module fault. Consult manufacturer procedures before replacing—reprogramming or coding may be required.
  11. After repairs, clear codes and road-test to confirm the U0104 does not return. Re-scan to ensure no residual network errors.

Likely causes

  • Damaged wiring harness or chafed insulation at common routing points
  • Corroded or loose connector pins at the speed control module
  • Blown fuse or poor battery/ignition power feed to the module
  • Bus short to battery/ground or to CAN high/low
  • Module failure after water intrusion or impact damage

Fault status

⚠️ Status
U0104 - Lost Communication with Speed Control Module
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0 - 3.0 hours

Similar codes

U0100 U0101 U0121 U0073 U0155
Workshop Manuals

Repair manuals for 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.

199,00 UAH
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
Buy

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.

199,00 UAH
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
Buy

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.

199,00 UAH
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
Buy
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 .