Code
U3000
Generic
U — Network/User
Control Module
Views:
UK: 16
EN: 32
RU: 17
AI status
Completed
Completed
100%
Causes
- Internal control module hardware or firmware fault
- Lost communication on vehicle network (CAN/LIN/Flexray)
- Corroded, loose, or damaged connector or wiring
- Blown fuse or poor power supply / ground
- Low or unstable battery voltage
- Water intrusion or physical damage to module
Symptoms
- One or more vehicle systems controlled by the module do not operate
- Warning lights or multiple network-related warnings on dash
- Scanner cannot communicate with the affected module
- Intermittent or permanent loss of function (locks, displays, sensors)
- Erratic behavior of related components or systems
- Possible drivability issues if powertrain-related module
What to check
- Retrieve freeze frame and all current/PENDING U- and P-codes with a capable scan tool
- Check battery voltage (key on, engine off and cranking) — should be ~12.6V static; >11V while cranking
- Inspect fuses and power distribution related to the module
- Visually inspect module connectors and wiring for corrosion, bent pins, water, or damage
- Check module ground resistance to chassis (
- Measure CAN High/Low idle voltages at an accessible bus connector
Signal parameters
- Battery supply: nominal 11–14.5 V (key on); low voltage can cause faults
- Ground: chassis/engine ground resistance should be very low (
- CAN bus (recessive): CAN_H ≈ 2.5 V, CAN_L ≈ 2.5 V (differential ~0 V)
- CAN bus (dominant): CAN_H ≈ 3.5 V, CAN_L ≈ 1.5 V (differential ~2.0 V)
- Typical CAN bus termination: ~60 Ω between CAN_H and CAN_L at rest
- Common bus speeds: 125 kbps, 250 kbps, 500 kbps (verify vehicle specification)
Diagnostic algorithm
- Confirm the code: connect a full-function scan tool, record DTCs and freeze-frame data, note occurrence conditions.
- Check for related/secondary codes (other U-codes, P-codes) to narrow network or specific module issues.
- Verify battery voltage and state of charge; charge or load-test battery if below spec.
- Inspect fuses and relay(s) supplying the module; measure supply voltage at module power pins with key on.
- Inspect module connectors and wiring for corrosion, water, heat damage, bent pins, or loose pins; repair as needed.
- Verify ground integrity: measure voltage drop between module ground and chassis while activating electrical loads.
- Measure CAN_H and CAN_L at module connector and at a second point on the bus; confirm correct recessive/dominant voltages and termination resistance.
- If bus voltages are abnormal, isolate wiring harness sections, check for shorts to battery/ground and opens; repair wiring or connectors.
- If network is healthy but module does not respond, check for software updates, reflash or reprogram module per manufacturer procedure.
- If reflash fails or module still reports internal error after power/communication verified, consider replacing the module and programming/configuring it to the vehicle.
- After repairs or replacement, clear codes, cycle ignition, and road/test to confirm DTC does not return and vehicle systems function correctly.
- Document findings and any software calibrations applied; advise customer if OEM programming tools or dealer-level service are required.
Likely causes
- Power/ground fault to the affected module (fuse, connector, battery)
- CAN bus wiring short/open or high resistance at splice/connector
- Module internal failure (processor, memory corruption)
- Failed or interrupted module reflash or incorrect calibration
- Connector corrosion or pin damage at module harness
Fault status
Status
Control Module — internal fault or communication failure detected. Module may be not responding or reporting an internal error; inspect power, ground, network, and module integrity.
Repair difficulty: Hard
Diagnostic time: 1.0-3.5 hours
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Code
U3000
HYUNDAI
U — Network/User
Control Module
Views:
UK: 18
EN: 19
RU: 18
AI status
Completed
Completed
100%
Causes
- Internal control module hardware or firmware fault
- Lost communication on vehicle network (CAN/LIN/Flexray)
- Corroded, loose, or damaged connector or wiring
- Blown fuse or poor power supply / ground
- Low or unstable battery voltage
- Water intrusion or physical damage to module
Symptoms
- One or more vehicle systems controlled by the module do not operate
- Warning lights or multiple network-related warnings on dash
- Scanner cannot communicate with the affected module
- Intermittent or permanent loss of function (locks, displays, sensors)
- Erratic behavior of related components or systems
- Possible drivability issues if powertrain-related module
What to check
- Retrieve freeze frame and all current/PENDING U- and P-codes with a capable scan tool
- Check battery voltage (key on, engine off and cranking) — should be ~12.6V static; >11V while cranking
- Inspect fuses and power distribution related to the module
- Visually inspect module connectors and wiring for corrosion, bent pins, water, or damage
- Check module ground resistance to chassis (
- Measure CAN High/Low idle voltages at an accessible bus connector
Signal parameters
- Battery supply: nominal 11–14.5 V (key on); low voltage can cause faults
- Ground: chassis/engine ground resistance should be very low (
- CAN bus (recessive): CAN_H ≈ 2.5 V, CAN_L ≈ 2.5 V (differential ~0 V)
- CAN bus (dominant): CAN_H ≈ 3.5 V, CAN_L ≈ 1.5 V (differential ~2.0 V)
- Typical CAN bus termination: ~60 Ω between CAN_H and CAN_L at rest
- Common bus speeds: 125 kbps, 250 kbps, 500 kbps (verify vehicle specification)
Diagnostic algorithm
- Confirm the code: connect a full-function scan tool, record DTCs and freeze-frame data, note occurrence conditions.
- Check for related/secondary codes (other U-codes, P-codes) to narrow network or specific module issues.
- Verify battery voltage and state of charge; charge or load-test battery if below spec.
- Inspect fuses and relay(s) supplying the module; measure supply voltage at module power pins with key on.
- Inspect module connectors and wiring for corrosion, water, heat damage, bent pins, or loose pins; repair as needed.
- Verify ground integrity: measure voltage drop between module ground and chassis while activating electrical loads.
- Measure CAN_H and CAN_L at module connector and at a second point on the bus; confirm correct recessive/dominant voltages and termination resistance.
- If bus voltages are abnormal, isolate wiring harness sections, check for shorts to battery/ground and opens; repair wiring or connectors.
- If network is healthy but module does not respond, check for software updates, reflash or reprogram module per manufacturer procedure.
- If reflash fails or module still reports internal error after power/communication verified, consider replacing the module and programming/configuring it to the vehicle.
- After repairs or replacement, clear codes, cycle ignition, and road/test to confirm DTC does not return and vehicle systems function correctly.
- Document findings and any software calibrations applied; advise customer if OEM programming tools or dealer-level service are required.
Likely causes
- Power/ground fault to the affected module (fuse, connector, battery)
- CAN bus wiring short/open or high resistance at splice/connector
- Module internal failure (processor, memory corruption)
- Failed or interrupted module reflash or incorrect calibration
- Connector corrosion or pin damage at module harness
Fault status
Status
Control Module — internal fault or communication failure detected. Module may be not responding or reporting an internal error; inspect power, ground, network, and module integrity.
Repair difficulty: Hard
Diagnostic time: 1.0-3.5 hours
Similar codes
Your experience will help others
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Was this AI description helpful?
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👍 Like
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Send to email
Code
U3000
LAND ROVER
U — Network/User
Control Module
Views:
UK: 12
EN: 21
RU: 16
AI status
Completed
Completed
100%
Causes
- Internal control module hardware or firmware fault
- Lost communication on vehicle network (CAN/LIN/Flexray)
- Corroded, loose, or damaged connector or wiring
- Blown fuse or poor power supply / ground
- Low or unstable battery voltage
- Water intrusion or physical damage to module
Symptoms
- One or more vehicle systems controlled by the module do not operate
- Warning lights or multiple network-related warnings on dash
- Scanner cannot communicate with the affected module
- Intermittent or permanent loss of function (locks, displays, sensors)
- Erratic behavior of related components or systems
- Possible drivability issues if powertrain-related module
What to check
- Retrieve freeze frame and all current/PENDING U- and P-codes with a capable scan tool
- Check battery voltage (key on, engine off and cranking) — should be ~12.6V static; >11V while cranking
- Inspect fuses and power distribution related to the module
- Visually inspect module connectors and wiring for corrosion, bent pins, water, or damage
- Check module ground resistance to chassis (
- Measure CAN High/Low idle voltages at an accessible bus connector
Signal parameters
- Battery supply: nominal 11–14.5 V (key on); low voltage can cause faults
- Ground: chassis/engine ground resistance should be very low (
- CAN bus (recessive): CAN_H ≈ 2.5 V, CAN_L ≈ 2.5 V (differential ~0 V)
- CAN bus (dominant): CAN_H ≈ 3.5 V, CAN_L ≈ 1.5 V (differential ~2.0 V)
- Typical CAN bus termination: ~60 Ω between CAN_H and CAN_L at rest
- Common bus speeds: 125 kbps, 250 kbps, 500 kbps (verify vehicle specification)
Diagnostic algorithm
- Confirm the code: connect a full-function scan tool, record DTCs and freeze-frame data, note occurrence conditions.
- Check for related/secondary codes (other U-codes, P-codes) to narrow network or specific module issues.
- Verify battery voltage and state of charge; charge or load-test battery if below spec.
- Inspect fuses and relay(s) supplying the module; measure supply voltage at module power pins with key on.
- Inspect module connectors and wiring for corrosion, water, heat damage, bent pins, or loose pins; repair as needed.
- Verify ground integrity: measure voltage drop between module ground and chassis while activating electrical loads.
- Measure CAN_H and CAN_L at module connector and at a second point on the bus; confirm correct recessive/dominant voltages and termination resistance.
- If bus voltages are abnormal, isolate wiring harness sections, check for shorts to battery/ground and opens; repair wiring or connectors.
- If network is healthy but module does not respond, check for software updates, reflash or reprogram module per manufacturer procedure.
- If reflash fails or module still reports internal error after power/communication verified, consider replacing the module and programming/configuring it to the vehicle.
- After repairs or replacement, clear codes, cycle ignition, and road/test to confirm DTC does not return and vehicle systems function correctly.
- Document findings and any software calibrations applied; advise customer if OEM programming tools or dealer-level service are required.
Likely causes
- Power/ground fault to the affected module (fuse, connector, battery)
- CAN bus wiring short/open or high resistance at splice/connector
- Module internal failure (processor, memory corruption)
- Failed or interrupted module reflash or incorrect calibration
- Connector corrosion or pin damage at module harness
Fault status
Status
Control Module — internal fault or communication failure detected. Module may be not responding or reporting an internal error; inspect power, ground, network, and module integrity.
Repair difficulty: Hard
Diagnostic time: 1.0-3.5 hours
Similar codes
Workshop Manuals
Repair manuals for LAND ROVER
3
Land Rover Defender 300Tdi — Workshop Manual (1996 model year)
Workshop ManualLand Rover Defender Workshop Manual Supplement & Body Repair Manual (1999 & 2002 MY)
Workshop ManualLand Rover Range Rover — Electrical Library (LRL 0453ENG, 2002)
Workshop ManualYour experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email