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U0191 — Lost Communication With Television

Detailed page for trouble code U0191.

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Code

U0191

Generic U — Network/User

Lost Communication With Television

Views: UK: 26 EN: 44 RU: 29
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • No power or ground to the television/display module (blown fuse, open feed, poor ground)
  • Open or shorted wiring between the module and the communication bus
  • Faulty or corroded connector at the television module
  • Failed television/display module or damaged bus transceiver
  • Bus wiring shorted to battery, ground or other circuit
  • Missing/incorrect module programming or corrupted software

Symptoms

  • Television/display does not power on or remains blank
  • Infotainment features related to the TV module inoperative
  • Multiple communication-related U-codes or network errors present
  • Intermittent display operation or loss of functions when driving
  • Other modules show communication timeouts or reduced functionality

What to check

  • Use a scan tool to read freeze frame, event data and related U-codes; verify whether the television module is present on the network
  • Check for other U-codes indicating broader bus failure (e.g., U0100, U0121)
  • Visually inspect fuses and relays related to the TV/display power feed
  • Inspect the television module connector for corrosion, bent pins or water intrusion
  • Verify battery voltage at module power pin with ignition in proper state
  • Verify good engine/vehicle ground at the module mounting/ground stud

Signal parameters

  • Module supply: nominal vehicle battery ~11–14 V with ignition in RUN/ACC as required
  • Ground:
  • CAN bus idle voltages: CAN_H ~2.5–3.5 V, CAN_L ~1.5–2.5 V (recessive ~2.5 V each); dominant differential ~1–2 V
  • Bus data rates commonly 125, 250 or 500 kbps (verify vehicle-specific rate with scan tool)
  • LIN lines: single-wire low-speed serial; check for proper idle voltage per manufacturer (often pulled up to battery via resistor)
  • MOST/optical networks: optical fiber continuity and correct light transmission (if used for TV/video)

Diagnostic algorithm

  1. Connect a capable scan tool and confirm U0191 is current or stored. Record freeze frame and related codes.
  2. Verify whether the TV/display module reports on the bus (module present list) or responds to basic diagnostic requests.
  3. Check fuses and power feed for the television module. Restore or replace any blown fuses and verify proper voltage at the module connector.
  4. Verify ground at the module. Clean and tighten ground connections if high resistance is found.
  5. Visually inspect the module and harness for damage, corrosion, water intrusion or disconnected connectors. Repair as needed.
  6. Using a multimeter, measure CAN/LIN/MOST/Ethernet wiring for continuity and shorts to power/ground. Repair any wiring faults.
  7. With ignition on, measure CAN_H and CAN_L idle voltages. If voltages are out of expected range, isolate and test segments to find the fault (measure at module and gateway)
  8. If bus appears held dominant or shorted, disconnect suspect module connectors one at a time (with ignition off as required) to identify which module causes the bus fault.
  9. If wiring and bus are good but module does not respond, try cycle ignition and perform a module wake/reboot procedure per manufacturer. Re-flash or update module software if an update is available and recommended.
  10. If module still fails to communicate after power/ground and bus verified good, consider replacing the television/display module. Verify programming/coding of replacement module per vehicle service procedures.
  11. After repairs, clear codes, perform network scan and verify normal operation and no reoccurrence of U0191.

Likely causes

  • Blown fuse or loose power/ground at the television module
  • Damaged or disconnected CAN/LIN/MOST/Ethernet harness to the TV module
  • Failed bus transceiver on the television module
  • Corroded or bent pins in the module connector
  • Faulty module due to water intrusion or impact
  • Incorrect module replacement or missing reflash after module swap

Fault status

⚠️ Status
Lost Communication With Television — the vehicle communications network cannot reach the television/display module. Check power, ground, connectors, wiring and bus integrity; module may be unresponsive or failed.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours

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6,645

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Code

U0191

HYUNDAI U — Network/User

Lost Communication With Television

Views: UK: 22 EN: 30 RU: 23
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • No power or ground to the television/display module (blown fuse, open feed, poor ground)
  • Open or shorted wiring between the module and the communication bus
  • Faulty or corroded connector at the television module
  • Failed television/display module or damaged bus transceiver
  • Bus wiring shorted to battery, ground or other circuit
  • Missing/incorrect module programming or corrupted software

Symptoms

  • Television/display does not power on or remains blank
  • Infotainment features related to the TV module inoperative
  • Multiple communication-related U-codes or network errors present
  • Intermittent display operation or loss of functions when driving
  • Other modules show communication timeouts or reduced functionality

What to check

  • Use a scan tool to read freeze frame, event data and related U-codes; verify whether the television module is present on the network
  • Check for other U-codes indicating broader bus failure (e.g., U0100, U0121)
  • Visually inspect fuses and relays related to the TV/display power feed
  • Inspect the television module connector for corrosion, bent pins or water intrusion
  • Verify battery voltage at module power pin with ignition in proper state
  • Verify good engine/vehicle ground at the module mounting/ground stud

Signal parameters

  • Module supply: nominal vehicle battery ~11–14 V with ignition in RUN/ACC as required
  • Ground:
  • CAN bus idle voltages: CAN_H ~2.5–3.5 V, CAN_L ~1.5–2.5 V (recessive ~2.5 V each); dominant differential ~1–2 V
  • Bus data rates commonly 125, 250 or 500 kbps (verify vehicle-specific rate with scan tool)
  • LIN lines: single-wire low-speed serial; check for proper idle voltage per manufacturer (often pulled up to battery via resistor)
  • MOST/optical networks: optical fiber continuity and correct light transmission (if used for TV/video)

Diagnostic algorithm

  1. Connect a capable scan tool and confirm U0191 is current or stored. Record freeze frame and related codes.
  2. Verify whether the TV/display module reports on the bus (module present list) or responds to basic diagnostic requests.
  3. Check fuses and power feed for the television module. Restore or replace any blown fuses and verify proper voltage at the module connector.
  4. Verify ground at the module. Clean and tighten ground connections if high resistance is found.
  5. Visually inspect the module and harness for damage, corrosion, water intrusion or disconnected connectors. Repair as needed.
  6. Using a multimeter, measure CAN/LIN/MOST/Ethernet wiring for continuity and shorts to power/ground. Repair any wiring faults.
  7. With ignition on, measure CAN_H and CAN_L idle voltages. If voltages are out of expected range, isolate and test segments to find the fault (measure at module and gateway)
  8. If bus appears held dominant or shorted, disconnect suspect module connectors one at a time (with ignition off as required) to identify which module causes the bus fault.
  9. If wiring and bus are good but module does not respond, try cycle ignition and perform a module wake/reboot procedure per manufacturer. Re-flash or update module software if an update is available and recommended.
  10. If module still fails to communicate after power/ground and bus verified good, consider replacing the television/display module. Verify programming/coding of replacement module per vehicle service procedures.
  11. After repairs, clear codes, perform network scan and verify normal operation and no reoccurrence of U0191.

Likely causes

  • Blown fuse or loose power/ground at the television module
  • Damaged or disconnected CAN/LIN/MOST/Ethernet harness to the TV module
  • Failed bus transceiver on the television module
  • Corroded or bent pins in the module connector
  • Faulty module due to water intrusion or impact
  • Incorrect module replacement or missing reflash after module swap

Fault status

⚠️ Status
Lost Communication With Television — the vehicle communications network cannot reach the television/display module. Check power, ground, connectors, wiring and bus integrity; module may be unresponsive or failed.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours

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Code

U0191

LAND ROVER U — Network/User

Lost communication with the television

Views: UK: 17 EN: 27 RU: 20
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • No power or ground to the television/display module (blown fuse, open feed, poor ground)
  • Open or shorted wiring between the module and the communication bus
  • Faulty or corroded connector at the television module
  • Failed television/display module or damaged bus transceiver
  • Bus wiring shorted to battery, ground or other circuit
  • Missing/incorrect module programming or corrupted software

Symptoms

  • Television/display does not power on or remains blank
  • Infotainment features related to the TV module inoperative
  • Multiple communication-related U-codes or network errors present
  • Intermittent display operation or loss of functions when driving
  • Other modules show communication timeouts or reduced functionality

What to check

  • Use a scan tool to read freeze frame, event data and related U-codes; verify whether the television module is present on the network
  • Check for other U-codes indicating broader bus failure (e.g., U0100, U0121)
  • Visually inspect fuses and relays related to the TV/display power feed
  • Inspect the television module connector for corrosion, bent pins or water intrusion
  • Verify battery voltage at module power pin with ignition in proper state
  • Verify good engine/vehicle ground at the module mounting/ground stud

Signal parameters

  • Module supply: nominal vehicle battery ~11–14 V with ignition in RUN/ACC as required
  • Ground:
  • CAN bus idle voltages: CAN_H ~2.5–3.5 V, CAN_L ~1.5–2.5 V (recessive ~2.5 V each); dominant differential ~1–2 V
  • Bus data rates commonly 125, 250 or 500 kbps (verify vehicle-specific rate with scan tool)
  • LIN lines: single-wire low-speed serial; check for proper idle voltage per manufacturer (often pulled up to battery via resistor)
  • MOST/optical networks: optical fiber continuity and correct light transmission (if used for TV/video)

Diagnostic algorithm

  1. Connect a capable scan tool and confirm U0191 is current or stored. Record freeze frame and related codes.
  2. Verify whether the TV/display module reports on the bus (module present list) or responds to basic diagnostic requests.
  3. Check fuses and power feed for the television module. Restore or replace any blown fuses and verify proper voltage at the module connector.
  4. Verify ground at the module. Clean and tighten ground connections if high resistance is found.
  5. Visually inspect the module and harness for damage, corrosion, water intrusion or disconnected connectors. Repair as needed.
  6. Using a multimeter, measure CAN/LIN/MOST/Ethernet wiring for continuity and shorts to power/ground. Repair any wiring faults.
  7. With ignition on, measure CAN_H and CAN_L idle voltages. If voltages are out of expected range, isolate and test segments to find the fault (measure at module and gateway)
  8. If bus appears held dominant or shorted, disconnect suspect module connectors one at a time (with ignition off as required) to identify which module causes the bus fault.
  9. If wiring and bus are good but module does not respond, try cycle ignition and perform a module wake/reboot procedure per manufacturer. Re-flash or update module software if an update is available and recommended.
  10. If module still fails to communicate after power/ground and bus verified good, consider replacing the television/display module. Verify programming/coding of replacement module per vehicle service procedures.
  11. After repairs, clear codes, perform network scan and verify normal operation and no reoccurrence of U0191.

Likely causes

  • Blown fuse or loose power/ground at the television module
  • Damaged or disconnected CAN/LIN/MOST/Ethernet harness to the TV module
  • Failed bus transceiver on the television module
  • Corroded or bent pins in the module connector
  • Faulty module due to water intrusion or impact
  • Incorrect module replacement or missing reflash after module swap

Fault status

⚠️ Status
Lost Communication With Television — the vehicle communications network cannot reach the television/display module. Check power, ground, connectors, wiring and bus integrity; module may be unresponsive or failed.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours

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+100 karma for a short comment :)
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