Code
U0424
Generic
U — Network/User
Invalid Data Received From HVAC Control Module
AI status
Completed
Completed
100%
Causes
- HVAC control module software/firmware fault or internal failure
- Loss of or intermittent CAN/LIN network communication (open, short, high resistance)
- Corroded, loose, or damaged connector(s) or wiring to HVAC module
- Incorrect module programming or incompatible replacement module
- Low or missing module supply voltage or poor ground
- Network bus termination resistor missing or faulty
Symptoms
- HVAC controls or display inoperative, intermittent, or showing incorrect information
- Loss of one or more HVAC features (automatic climate control, blower speed feedback, mode selection)
- MIL or dash communication warning lamps may illuminate
- Other modules reporting related U-codes or communication faults
- Erratic or frozen HVAC temperature readouts
What to check
- Retrieve and record all stored DTCs and freeze frame data from all modules
- Check for other U-codes on the same network (helps locate bus/network issues)
- Attempt to communicate with the HVAC module using a scan tool (present/absent, respond to requests)
- Visually inspect HVAC module connector and wiring for corrosion, damage, or water intrusion
- Verify HVAC module supply voltage (B+) and ground integrity
- Measure CAN/LIN bus voltages and waveform quality at the HVAC module connector
Signal parameters
- Vehicle battery supply to HVAC module: ~11–14.5 V when engine running
- Module ground:
- CAN bus idle (recessive) voltages: CANH ≈ 2.5 V, CANL ≈ 2.5 V
- CAN bus dominant voltages: CANH ≈ 3.5 V, CANL ≈ 1.5 V (typical differential ≈ 2 V)
- Expected CAN data rate: commonly 250 kb/s or 500 kb/s depending on vehicle (verify factory spec)
- Termination resistance: ~60 ohms measured end-to-end between CANH and CANL
Diagnostic algorithm
- Read and record all DTCs and freeze frame data from all modules. Note time stamps and related codes.
- Verify the HVAC module is present and responsive on the network using a scan tool. Attempt to view live data or actuate HVAC functions from the tool.
- If HVAC module does not respond, check B+ and ground at the module connector. Repair any low voltage or poor ground before proceeding.
- Inspect wiring and connector for signs of damage, corrosion, or moisture. Repair or replace damaged connectors/wiring.
- With key on, engine off (or per service manual), measure CANH and CANL at the HVAC connector. Confirm recessive and dominant voltage levels and proper differential. If out of range, isolate wiring or nearby modules.
- Check network termination resistance (with power off). Replace missing or faulty terminators as required.
- If bus voltages and wiring are good, attempt module reflash or reprogram to the latest calibration per factory procedures (verify correct part number).
- If problem persists after wiring and software verification, consider replacing the HVAC control module. Use a known-good or programmed replacement and repeat communication checks.
- After repairs, clear codes and perform a full system test. Monitor for recurrence and confirm HVAC functions operate normally.
Likely causes
- Faulty HVAC module (software or hardware)
- CAN/LIN wiring open, shorted, or high resistance between HVAC module and bus
- Poor ground or low battery voltage at HVAC module
- Corroded/poor connector pins at HVAC harness
- Bus termination or multiple device conflict on CAN network
Fault status
Status
Invalid Data Received From HVAC Control Module — receiving controller detected malformed, out-of-range, or corrupted messages from the HVAC module on the vehicle communication bus.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
Similar codes
Repair manuals
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Code
U0424
HYUNDAI
U — Network/User
Invalid Data Received From HVAC Control Module
AI status
Completed
Completed
100%
Causes
- HVAC control module software/firmware fault or internal failure
- Loss of or intermittent CAN/LIN network communication (open, short, high resistance)
- Corroded, loose, or damaged connector(s) or wiring to HVAC module
- Incorrect module programming or incompatible replacement module
- Low or missing module supply voltage or poor ground
- Network bus termination resistor missing or faulty
Symptoms
- HVAC controls or display inoperative, intermittent, or showing incorrect information
- Loss of one or more HVAC features (automatic climate control, blower speed feedback, mode selection)
- MIL or dash communication warning lamps may illuminate
- Other modules reporting related U-codes or communication faults
- Erratic or frozen HVAC temperature readouts
What to check
- Retrieve and record all stored DTCs and freeze frame data from all modules
- Check for other U-codes on the same network (helps locate bus/network issues)
- Attempt to communicate with the HVAC module using a scan tool (present/absent, respond to requests)
- Visually inspect HVAC module connector and wiring for corrosion, damage, or water intrusion
- Verify HVAC module supply voltage (B+) and ground integrity
- Measure CAN/LIN bus voltages and waveform quality at the HVAC module connector
Signal parameters
- Vehicle battery supply to HVAC module: ~11–14.5 V when engine running
- Module ground:
- CAN bus idle (recessive) voltages: CANH ≈ 2.5 V, CANL ≈ 2.5 V
- CAN bus dominant voltages: CANH ≈ 3.5 V, CANL ≈ 1.5 V (typical differential ≈ 2 V)
- Expected CAN data rate: commonly 250 kb/s or 500 kb/s depending on vehicle (verify factory spec)
- Termination resistance: ~60 ohms measured end-to-end between CANH and CANL
Diagnostic algorithm
- Read and record all DTCs and freeze frame data from all modules. Note time stamps and related codes.
- Verify the HVAC module is present and responsive on the network using a scan tool. Attempt to view live data or actuate HVAC functions from the tool.
- If HVAC module does not respond, check B+ and ground at the module connector. Repair any low voltage or poor ground before proceeding.
- Inspect wiring and connector for signs of damage, corrosion, or moisture. Repair or replace damaged connectors/wiring.
- With key on, engine off (or per service manual), measure CANH and CANL at the HVAC connector. Confirm recessive and dominant voltage levels and proper differential. If out of range, isolate wiring or nearby modules.
- Check network termination resistance (with power off). Replace missing or faulty terminators as required.
- If bus voltages and wiring are good, attempt module reflash or reprogram to the latest calibration per factory procedures (verify correct part number).
- If problem persists after wiring and software verification, consider replacing the HVAC control module. Use a known-good or programmed replacement and repeat communication checks.
- After repairs, clear codes and perform a full system test. Monitor for recurrence and confirm HVAC functions operate normally.
Likely causes
- Faulty HVAC module (software or hardware)
- CAN/LIN wiring open, shorted, or high resistance between HVAC module and bus
- Poor ground or low battery voltage at HVAC module
- Corroded/poor connector pins at HVAC harness
- Bus termination or multiple device conflict on CAN network
Fault status
Status
Invalid Data Received From HVAC Control Module — receiving controller detected malformed, out-of-range, or corrupted messages from the HVAC module on the vehicle communication bus.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
Similar codes
Repair manuals
Manual library for HYUNDAI
371
Browse 371 HYUNDAI manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.
HYUNDAI
-
HYUNDAI: 2023
-
Elantra
-
Elantra N
-
Kona N
-
Tucson
- Hybrid Blue
- Hybrid Limited
- Hybrid SEL Convenience
- Limited, Eng CD G4EN, 4WD
- Limited, Eng CD G4EN, FWD
- Limited, Eng CD G4KN, 4WD
- Limited, Eng CD G4KN, FWD
- N Line, Eng CD G4EN, 4WD
- N Line, Eng CD G4EN, FWD
- N Line, Eng CD G4KN, 4WD
- N Line, Eng CD G4KN, FWD
- Plug-In Hybrid Limited
- Plug-In Hybrid SEL
- SE, Eng CD G4EN, 4WD
- SE, Eng CD G4EN, FWD
- SE, Eng CD G4KN, 4WD
- SE, Eng CD G4KN, FWD
- SEL, Eng CD G4EN, 4WD
- SEL, Eng CD G4EN, FWD
- SEL, Eng CD G4KN, 4WD
- SEL, Eng CD G4KN, FWD
- XRT, Eng CD G4EN, 4WD
- XRT, Eng CD G4EN, FWD
- XRT, Eng CD G4KN, 4WD
- XRT, Eng CD G4KN, FWD
-
-
HYUNDAI: 2022
-
Elantra N
-
Kona N
-
Veloster N
-
HYUNDAI: 2021
-
Veloster N
-
HYUNDAI: 2020
-
Palisade
-
Veloster N
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Code
U0424
LAND ROVER
U — Network/User
Invalid data received from the heating control module, ventilation and air conditioning
AI status
Completed
Completed
100%
Causes
- HVAC control module software/firmware fault or internal failure
- Loss of or intermittent CAN/LIN network communication (open, short, high resistance)
- Corroded, loose, or damaged connector(s) or wiring to HVAC module
- Incorrect module programming or incompatible replacement module
- Low or missing module supply voltage or poor ground
- Network bus termination resistor missing or faulty
Symptoms
- HVAC controls or display inoperative, intermittent, or showing incorrect information
- Loss of one or more HVAC features (automatic climate control, blower speed feedback, mode selection)
- MIL or dash communication warning lamps may illuminate
- Other modules reporting related U-codes or communication faults
- Erratic or frozen HVAC temperature readouts
What to check
- Retrieve and record all stored DTCs and freeze frame data from all modules
- Check for other U-codes on the same network (helps locate bus/network issues)
- Attempt to communicate with the HVAC module using a scan tool (present/absent, respond to requests)
- Visually inspect HVAC module connector and wiring for corrosion, damage, or water intrusion
- Verify HVAC module supply voltage (B+) and ground integrity
- Measure CAN/LIN bus voltages and waveform quality at the HVAC module connector
Signal parameters
- Vehicle battery supply to HVAC module: ~11–14.5 V when engine running
- Module ground:
- CAN bus idle (recessive) voltages: CANH ≈ 2.5 V, CANL ≈ 2.5 V
- CAN bus dominant voltages: CANH ≈ 3.5 V, CANL ≈ 1.5 V (typical differential ≈ 2 V)
- Expected CAN data rate: commonly 250 kb/s or 500 kb/s depending on vehicle (verify factory spec)
- Termination resistance: ~60 ohms measured end-to-end between CANH and CANL
Diagnostic algorithm
- Read and record all DTCs and freeze frame data from all modules. Note time stamps and related codes.
- Verify the HVAC module is present and responsive on the network using a scan tool. Attempt to view live data or actuate HVAC functions from the tool.
- If HVAC module does not respond, check B+ and ground at the module connector. Repair any low voltage or poor ground before proceeding.
- Inspect wiring and connector for signs of damage, corrosion, or moisture. Repair or replace damaged connectors/wiring.
- With key on, engine off (or per service manual), measure CANH and CANL at the HVAC connector. Confirm recessive and dominant voltage levels and proper differential. If out of range, isolate wiring or nearby modules.
- Check network termination resistance (with power off). Replace missing or faulty terminators as required.
- If bus voltages and wiring are good, attempt module reflash or reprogram to the latest calibration per factory procedures (verify correct part number).
- If problem persists after wiring and software verification, consider replacing the HVAC control module. Use a known-good or programmed replacement and repeat communication checks.
- After repairs, clear codes and perform a full system test. Monitor for recurrence and confirm HVAC functions operate normally.
Likely causes
- Faulty HVAC module (software or hardware)
- CAN/LIN wiring open, shorted, or high resistance between HVAC module and bus
- Poor ground or low battery voltage at HVAC module
- Corroded/poor connector pins at HVAC harness
- Bus termination or multiple device conflict on CAN network
Fault status
Status
Invalid Data Received From HVAC Control Module — receiving controller detected malformed, out-of-range, or corrupted messages from the HVAC module on the vehicle communication bus.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
Similar codes
Repair manuals
Manual library for LAND ROVER
320
Browse 320 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.
LAND ROVER
-
LAND ROVER: 2022
-
Defender
- 90
- 90
- 90 S
- 90 S
- 90 V8
- 90 V8
- 90 V8 Carpathian Edition
- 90 V8 Carpathian Edition
- 90 X
- 90 X
- 90 X-Dynamic HSE
- 90 X-Dynamic HSE
- 90 X-Dynamic S
- 90 X-Dynamic S
- 90 X-Dynamic SE
- 90 X-Dynamic SE
- 110
- 110
- 110 S
- 110 S
- 110 SE
- 110 SE
- 110 V8
- 110 V8
- 110 V8 Carpathian Edition
- 110 V8 Carpathian Edition
- 110 X
- 110 X
- 110 X-Dynamic SE
- 110 X-Dynamic SE
- 110 XS Edition
- 110 XS Edition
-
Discovery
- R-Dynamic HSE
- R-Dynamic HSE
- R-Dynamic S, 2.0L Eng VIN X · 2.0L Eng VIN X2022: Discovery R-Dynamic S
- R-Dynamic S, 2.0L Eng VIN X · 2.0L Eng VIN X2022: Discovery R-Dynamic S
- R-Dynamic S, 3.0L Eng VIN U · 3.0L Eng VIN U2022: Discovery R-Dynamic S
- R-Dynamic S, 3.0L Eng VIN U · 3.0L Eng VIN U2022: Discovery R-Dynamic S
- S
- S
-
Discovery Sport
-
Range Rover
- Autobiography, 4.4L Eng VIN 7 · 4.4L Eng VIN 72022: Range Rover Autobiography
- Autobiography, 4.4L Eng VIN 7 · 4.4L Eng VIN 72022: Range Rover Autobiography
- Autobiography, 5.0L Eng VIN E · 5.0L Eng VIN E2022: Range Rover Autobiography
- Autobiography, 5.0L Eng VIN E · 5.0L Eng VIN E2022: Range Rover Autobiography
- 2022 Range Rover Base
- 2022 Range Rover Base
- First Edition
- First Edition
- HSE Westminster, 3.0L Eng VIN U · 3.0L Eng VIN U2022: Range Rover HSE Westminster
- HSE Westminster, 3.0L Eng VIN U · 3.0L Eng VIN U2022: Range Rover HSE Westminster
- HSE Westminster, 5.0L Eng VIN E · 5.0L Eng VIN E2022: Range Rover HSE Westminster
- HSE Westminster, 5.0L Eng VIN E · 5.0L Eng VIN E2022: Range Rover HSE Westminster
- SE, 3.0L Eng VIN U · 3.0L Eng VIN U2022: Range Rover SE
- SE, 3.0L Eng VIN U · 3.0L Eng VIN U2022: Range Rover SE
- SE, 4.4L Eng VIN 7 · 4.4L Eng VIN 72022: Range Rover SE
- SE, 4.4L Eng VIN 7 · 4.4L Eng VIN 72022: Range Rover SE
- SV
- SV
- SVAutobiography
- SVAutobiography
- SVAutobiography Dynamic
- SVAutobiography Dynamic
- SVAutobiography Dynamic Blk.
- SVAutobiography Dynamic Blk.
-
Range Rover Evoque
-
Range Rover Velar
- R-Dynamic HSE
- R-Dynamic HSE
- R-Dynamic S, 2.0L Eng VIN X · 2.0L Eng VIN X2022: Range Rover Velar R-Dynamic S
- R-Dynamic S, 2.0L Eng VIN X · 2.0L Eng VIN X2022: Range Rover Velar R-Dynamic S
- R-Dynamic S, 3.0L Eng VIN U · 3.0L Eng VIN U2022: Range Rover Velar R-Dynamic S
- R-Dynamic S, 3.0L Eng VIN U · 3.0L Eng VIN U2022: Range Rover Velar R-Dynamic S
- S, 2.0L Eng VIN X · 2.0L Eng VIN X2022: Range Rover Velar S
- S, 2.0L Eng VIN X · 2.0L Eng VIN X2022: Range Rover Velar S
- S, 3.0L Eng VIN U · 3.0L Eng VIN U2022: Range Rover Velar S
- S, 3.0L Eng VIN U · 3.0L Eng VIN U2022: Range Rover Velar S
-
-
LAND ROVER: 2021
-
Discovery
- R-Dynamic HSE
- R-Dynamic HSE
- R-Dynamic S, 2.0L Eng VIN X · 2.0L Eng VIN X2021: Discovery R-Dynamic S
- R-Dynamic S, 2.0L Eng VIN X · 2.0L Eng VIN X2021: Discovery R-Dynamic S
- R-Dynamic S, 3.0L Eng VIN U · 3.0L Eng VIN U2021: Discovery R-Dynamic S
- R-Dynamic S, 3.0L Eng VIN U · 3.0L Eng VIN U2021: Discovery R-Dynamic S
- S
- S
-
Discovery Sport
-
Range Rover
- Autobiography, 2.0L Eng VIN Y · 2.0L Eng VIN Y2021: Range Rover Autobiography
- Autobiography, 2.0L Eng VIN Y · 2.0L Eng VIN Y2021: Range Rover Autobiography
- Autobiography Fifty Edition
- Autobiography Fifty Edition
- 2021 Range Rover Base
- 2021 Range Rover Base
- HSE, 2.0L Eng VIN Y · 2.0L Eng VIN Y2021: Range Rover HSE
- HSE, 2.0L Eng VIN Y · 2.0L Eng VIN Y2021: Range Rover HSE
- HSE, 3.0L Eng VIN K · 3.0L Eng VIN K2021: Range Rover HSE
- HSE, 3.0L Eng VIN K · 3.0L Eng VIN K2021: Range Rover HSE
- HSE Westminster, 3.0L Eng VIN U · 3.0L Eng VIN U2021: Range Rover HSE Westminster
- HSE Westminster, 3.0L Eng VIN U · 3.0L Eng VIN U2021: Range Rover HSE Westminster
- HSE Westminster, 5.0L Eng VIN E · 5.0L Eng VIN E2021: Range Rover HSE Westminster
- HSE Westminster, 5.0L Eng VIN E · 5.0L Eng VIN E2021: Range Rover HSE Westminster
- SVAutobiography
- SVAutobiography
- SVAutobiography Dynamic
- SVAutobiography Dynamic
- SVAutobiography Dynamic Blk.
- SVAutobiography Dynamic Blk.
-
Range Rover Evoque
-
Range Rover Sport
- Autobiography, 2.0L Eng VIN Y · 2.0L Eng VIN Y2021: Range Rover Sport Autobiography
- Autobiography, 2.0L Eng VIN Y · 2.0L Eng VIN Y2021: Range Rover Sport Autobiography
- Autobiography, 5.0L Eng VIN E · 5.0L Eng VIN E2021: Range Rover Sport Autobiography
- Autobiography, 5.0L Eng VIN E · 5.0L Eng VIN E2021: Range Rover Sport Autobiography
- Autobiography Dynamic, 2.0L Eng VIN Y · 2.0L Eng VIN Y2021: Range Rover Sport Autobiography Dynamic
- Autobiography Dynamic, 2.0L Eng VIN Y · 2.0L Eng VIN Y2021: Range Rover Sport Autobiography Dynamic
- Autobiography Dynamic, 5.0L Eng VIN E · 5.0L Eng VIN E2021: Range Rover Sport Autobiography Dynamic
- Autobiography Dynamic, 5.0L Eng VIN E · 5.0L Eng VIN E2021: Range Rover Sport Autobiography Dynamic
- HSE Dynamic
- HSE Dynamic
- HSE Silver Edition, 2.0L Eng VIN Y · 2.0L Eng VIN Y2021: Range Rover Sport HSE Silver Edition
- HSE Silver Edition, 2.0L Eng VIN Y · 2.0L Eng VIN Y2021: Range Rover Sport HSE Silver Edition
- HSE Silver Edition, 3.0L Eng VIN K · 3.0L Eng VIN K2021: Range Rover Sport HSE Silver Edition
- HSE Silver Edition, 3.0L Eng VIN K · 3.0L Eng VIN K2021: Range Rover Sport HSE Silver Edition
- HSE Silver Edition, 3.0L Eng VIN U · 3.0L Eng VIN U2021: Range Rover Sport HSE Silver Edition
- HSE Silver Edition, 3.0L Eng VIN U · 3.0L Eng VIN U2021: Range Rover Sport HSE Silver Edition
- HST
- HST
- SE
- SE
- SVR
- SVR
- SVR Carbon Edition
- SVR Carbon Edition
-
Range Rover Velar
- R-Dynamic HSE
- R-Dynamic HSE
- R-Dynamic S, 2.0L Eng VIN X · 2.0L Eng VIN X2021: Range Rover Velar R-Dynamic S
- R-Dynamic S, 2.0L Eng VIN X · 2.0L Eng VIN X2021: Range Rover Velar R-Dynamic S
- R-Dynamic S, 3.0L Eng VIN U · 3.0L Eng VIN U2021: Range Rover Velar R-Dynamic S
- R-Dynamic S, 3.0L Eng VIN U · 3.0L Eng VIN U2021: Range Rover Velar R-Dynamic S
- S, 2.0L Eng VIN X · 2.0L Eng VIN X2021: Range Rover Velar S
- S, 2.0L Eng VIN X · 2.0L Eng VIN X2021: Range Rover Velar S
- S, 3.0L Eng VIN U · 3.0L Eng VIN U2021: Range Rover Velar S
- S, 3.0L Eng VIN U · 3.0L Eng VIN U2021: Range Rover Velar S
-
LAND ROVER: 2020
-
Defender
- 90 First Edition
- 90 First Edition
- 110 First Edition
- 110 First Edition
- 110 HSE
- 110 HSE
- 110 S
- 110 S
- 110 SE
- 110 SE
- 110 X
- 110 X
- 110, 2.0L Eng VIN X · 2.0L Eng VIN X2020: Defender 110
- 110, 2.0L Eng VIN X · 2.0L Eng VIN X2020: Defender 110
- 110, 3.0L Eng VIN U · 3.0L Eng VIN U2020: Defender 110
- 110, 3.0L Eng VIN U · 3.0L Eng VIN U2020: Defender 110
-
Discovery
- HSE, 3.0L Eng VIN K · 3.0L Eng VIN K2020: Discovery HSE
- HSE, 3.0L Eng VIN K · 3.0L Eng VIN K2020: Discovery HSE
- HSE, 3.0L Eng VIN V · 3.0L Eng VIN V2020: Discovery HSE
- HSE, 3.0L Eng VIN V · 3.0L Eng VIN V2020: Discovery HSE
- HSE Luxury, 3.0L Eng VIN K · 3.0L Eng VIN K2020: Discovery HSE Luxury
- HSE Luxury, 3.0L Eng VIN K · 3.0L Eng VIN K2020: Discovery HSE Luxury
- HSE Luxury, 3.0L Eng VIN V · 3.0L Eng VIN V2020: Discovery HSE Luxury
- HSE Luxury, 3.0L Eng VIN V · 3.0L Eng VIN V2020: Discovery HSE Luxury
- Landmark
- Landmark
- SE, 3.0L Eng VIN K · 3.0L Eng VIN K2020: Discovery SE
- SE, 3.0L Eng VIN K · 3.0L Eng VIN K2020: Discovery SE
- SE, 3.0L Eng VIN V · 3.0L Eng VIN V2020: Discovery SE
- SE, 3.0L Eng VIN V · 3.0L Eng VIN V2020: Discovery SE
-
Range Rover
- Autobiography
- Autobiography
- Base, 3.0L Eng VIN K · 3.0L Eng VIN K2020: Range Rover Base
- Base, 3.0L Eng VIN K · 3.0L Eng VIN K2020: Range Rover Base
- Base, 3.0L Eng VIN U · 3.0L Eng VIN U2020: Range Rover Base
- Base, 3.0L Eng VIN U · 3.0L Eng VIN U2020: Range Rover Base
- HSE, 2.0L Eng VIN Y · 2.0L Eng VIN Y2020: Range Rover HSE
- HSE, 2.0L Eng VIN Y · 2.0L Eng VIN Y2020: Range Rover HSE
- HSE, 3.0L Eng VIN K · 3.0L Eng VIN K2020: Range Rover HSE
- HSE, 3.0L Eng VIN K · 3.0L Eng VIN K2020: Range Rover HSE
- HSE, 3.0L Eng VIN U · 3.0L Eng VIN U2020: Range Rover HSE
- HSE, 3.0L Eng VIN U · 3.0L Eng VIN U2020: Range Rover HSE
- HSE, 5.0L Eng VIN E · 5.0L Eng VIN E2020: Range Rover HSE
- HSE, 5.0L Eng VIN E · 5.0L Eng VIN E2020: Range Rover HSE
- SVAutobiography
- SVAutobiography
- SVAutobiography Dynamic
- SVAutobiography Dynamic
-
Range Rover Evoque
-
Range Rover Sport
- Autobiography Dynamic, 2.0L Eng VIN Y · 2.0L Eng VIN Y2020: Range Rover Sport Autobiography Dynamic
- Autobiography Dynamic, 2.0L Eng VIN Y · 2.0L Eng VIN Y2020: Range Rover Sport Autobiography Dynamic
- Autobiography Dynamic, 5.0L Eng VIN E · 5.0L Eng VIN E2020: Range Rover Sport Autobiography Dynamic
- Autobiography Dynamic, 5.0L Eng VIN E · 5.0L Eng VIN E2020: Range Rover Sport Autobiography Dynamic
- HSE, 3.0L Eng VIN K · 3.0L Eng VIN K2020: Range Rover Sport HSE
- HSE, 3.0L Eng VIN K · 3.0L Eng VIN K2020: Range Rover Sport HSE
- HSE, 3.0L Eng VIN U · 3.0L Eng VIN U2020: Range Rover Sport HSE
- HSE, 3.0L Eng VIN U · 3.0L Eng VIN U2020: Range Rover Sport HSE
- HSE, 5.0L Eng VIN E · 5.0L Eng VIN E2020: Range Rover Sport HSE
- HSE, 5.0L Eng VIN E · 5.0L Eng VIN E2020: Range Rover Sport HSE
- HSE Dynamic
- HSE Dynamic
- HSE PHEV
- HSE PHEV
- HST
- HST
- SE, 3.0L Eng VIN K · 3.0L Eng VIN K2020: Range Rover Sport SE
- SE, 3.0L Eng VIN K · 3.0L Eng VIN K2020: Range Rover Sport SE
- SE, 3.0L Eng VIN U · 3.0L Eng VIN U2020: Range Rover Sport SE
- SE, 3.0L Eng VIN U · 3.0L Eng VIN U2020: Range Rover Sport SE
- SVR
- SVR
-
Range Rover Velar
- R-Dynamic HSE
- R-Dynamic HSE
- R-Dynamic S, 2.0L Eng VIN X · 2.0L Eng VIN X2020: Range Rover Velar R-Dynamic S
- R-Dynamic S, 2.0L Eng VIN X · 2.0L Eng VIN X2020: Range Rover Velar R-Dynamic S
- R-Dynamic S, 3.0L Eng VIN V · 3.0L Eng VIN V2020: Range Rover Velar R-Dynamic S
- R-Dynamic S, 3.0L Eng VIN V · 3.0L Eng VIN V2020: Range Rover Velar R-Dynamic S
- S, 2.0L Eng VIN X · 2.0L Eng VIN X2020: Range Rover Velar S
- S, 2.0L Eng VIN X · 2.0L Eng VIN X2020: Range Rover Velar S
- S, 3.0L Eng VIN V · 3.0L Eng VIN V2020: Range Rover Velar S
- S, 3.0L Eng VIN V · 3.0L Eng VIN V2020: Range Rover Velar S
- SVAutobiography Dyn.
- SVAutobiography Dyn.
-
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Send to email
Code
U0424
OPEL
U — Network/User
Invalid Signal from ECC (Electronic Climate Control)
AI status
Completed
Completed
100%
Causes
- HVAC control module software/firmware fault or internal failure
- Loss of or intermittent CAN/LIN network communication (open, short, high resistance)
- Corroded, loose, or damaged connector(s) or wiring to HVAC module
- Incorrect module programming or incompatible replacement module
- Low or missing module supply voltage or poor ground
- Network bus termination resistor missing or faulty
Symptoms
- HVAC controls or display inoperative, intermittent, or showing incorrect information
- Loss of one or more HVAC features (automatic climate control, blower speed feedback, mode selection)
- MIL or dash communication warning lamps may illuminate
- Other modules reporting related U-codes or communication faults
- Erratic or frozen HVAC temperature readouts
What to check
- Retrieve and record all stored DTCs and freeze frame data from all modules
- Check for other U-codes on the same network (helps locate bus/network issues)
- Attempt to communicate with the HVAC module using a scan tool (present/absent, respond to requests)
- Visually inspect HVAC module connector and wiring for corrosion, damage, or water intrusion
- Verify HVAC module supply voltage (B+) and ground integrity
- Measure CAN/LIN bus voltages and waveform quality at the HVAC module connector
Signal parameters
- Vehicle battery supply to HVAC module: ~11–14.5 V when engine running
- Module ground:
- CAN bus idle (recessive) voltages: CANH ≈ 2.5 V, CANL ≈ 2.5 V
- CAN bus dominant voltages: CANH ≈ 3.5 V, CANL ≈ 1.5 V (typical differential ≈ 2 V)
- Expected CAN data rate: commonly 250 kb/s or 500 kb/s depending on vehicle (verify factory spec)
- Termination resistance: ~60 ohms measured end-to-end between CANH and CANL
Diagnostic algorithm
- Read and record all DTCs and freeze frame data from all modules. Note time stamps and related codes.
- Verify the HVAC module is present and responsive on the network using a scan tool. Attempt to view live data or actuate HVAC functions from the tool.
- If HVAC module does not respond, check B+ and ground at the module connector. Repair any low voltage or poor ground before proceeding.
- Inspect wiring and connector for signs of damage, corrosion, or moisture. Repair or replace damaged connectors/wiring.
- With key on, engine off (or per service manual), measure CANH and CANL at the HVAC connector. Confirm recessive and dominant voltage levels and proper differential. If out of range, isolate wiring or nearby modules.
- Check network termination resistance (with power off). Replace missing or faulty terminators as required.
- If bus voltages and wiring are good, attempt module reflash or reprogram to the latest calibration per factory procedures (verify correct part number).
- If problem persists after wiring and software verification, consider replacing the HVAC control module. Use a known-good or programmed replacement and repeat communication checks.
- After repairs, clear codes and perform a full system test. Monitor for recurrence and confirm HVAC functions operate normally.
Likely causes
- Faulty HVAC module (software or hardware)
- CAN/LIN wiring open, shorted, or high resistance between HVAC module and bus
- Poor ground or low battery voltage at HVAC module
- Corroded/poor connector pins at HVAC harness
- Bus termination or multiple device conflict on CAN network
Fault status
Status
Invalid Data Received From HVAC Control Module — receiving controller detected malformed, out-of-range, or corrupted messages from the HVAC module on the vehicle communication bus.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
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