Code
U0402
Generic
U — Network/User
Invalid Data Received From TCM
Views:
UK: 25
EN: 109
RU: 70
AI status
Completed
Completed
100%
Causes
- Corrupted or malformed CAN/LIN messages from the TCM
- Faulty or intermittent wiring/connector between TCM and network
- Poor power or ground to the TCM causing communication errors
- Software/firmware mismatch, incomplete programming, or corrupted TCM calibration
- Failed or failing TCM hardware
- Network bus problems (termination, excessive bus load, noise/EMI)
Symptoms
- Transmission may enter limp-home mode or default shift strategy (depends on vehicle)
- MIL/CEL or transmission warning lamp illuminated
- Loss of shift control or abnormal shifting behavior
- Other modules reporting U-codes or loss of communication with TCM
- Stored freeze frame or snapshot with unexpected message values
What to check
- Read all stored and pending codes from all modules; note freeze frame data and module IDs
- Verify battery voltage is within specification (with key on and engine off and during cranking)
- Inspect TCM connector and harness for damage, corrosion, or water intrusion
- Check for other U-codes that indicate network-wide or related-module problems
- Attempt communication with the TCM using a factory-level or bi-directional scan tool
- Capture CAN/LIN bus traffic with a capable scan tool or oscilloscope and look for missing, malformed, or out-of-range frames
Signal parameters
- TCM message IDs and expected periodic rates (e.g., gear selection, shift request, torque converter command) — verify presence and frequency
- Message payload fields: gear position, requested gear, transmission torque request, line pressure, lockup status — verify ranges and data format
- Message counters and checksums/CRC — verify counter increments and correct CRC
- CAN bus physical layer: CAN_H/CAN_L idle and dominant voltages, differential waveform integrity
- Network timing: expected message intervals and latency (missed or jittered messages may trigger U0402)
Diagnostic algorithm
- Record all current and pending U-codes and related freeze-frame information from every control module.
- Verify battery condition and charging system; ensure stable nominal system voltage during diagnostics.
- Visually inspect TCM connector, pins, and wiring for corrosion, bent pins, abrasion, or water; repair any damage.
- With a scan tool, attempt to communicate directly with the TCM. Note whether the TCM responds and which PIDs/messages are available.
- Capture live CAN traffic while operating the vehicle or cycling ignition. Look for TCM-originated frames with malformed data, incorrect counter/CRC, or irregular timing.
- Wiggle test harness and connectors while monitoring the bus for changes in traffic or new codes to reveal intermittent faults.
- Measure CAN_H/CAN_L idle voltages and use an oscilloscope to inspect waveforms for noise, reflections, or missing dominant/recessive transitions. Check termination resistance across bus.
- If a replacement TCM was recently installed, confirm correct part number, programming, and module coding. Reflash or update TCM software per manufacturer procedures if available.
- If physical layer and configuration are correct but invalid data persists, consider bench-testing or swapping the TCM (if a known good unit is available) to confirm module failure.
- After repairs, clear codes and perform a road test while monitoring for reappearance of U0402 and related codes. Verify normal transmission operation and that all expected TCM messages are valid.
Likely causes
- Loose or corroded connector pins at the TCM or at a splice in the CAN wiring
- Low battery voltage or bad battery/charging causing data corruption
- Recent repair or module replacement where the TCM was not programmed to vehicle
- Intermittent CAN physical layer fault (short to power/ground, high resistance)
- TCM internal failure producing incorrect frames or bad checksum/counter
Fault status
Status
Invalid data received from the Transmission Control Module (TCM). The receiving module detected message contents, format, checksum, counter, or timing that did not match expected values. Diagnostic data (freeze frame, message dump) should indicate offending frame and source module ID.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
Similar codes
Workshop Manuals
Available brands with manuals
1
LAND ROVER 1
Land Rover Defender Workshop Manual 1999-2002 MY
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
Code
U0402
HYUNDAI
U — Network/User
Invalid Data Received From Transmission Control Module
Views:
UK: 14
EN: 39
RU: 37
AI status
Completed
Completed
100%
Causes
- Corrupted or malformed CAN/LIN messages from the TCM
- Faulty or intermittent wiring/connector between TCM and network
- Poor power or ground to the TCM causing communication errors
- Software/firmware mismatch, incomplete programming, or corrupted TCM calibration
- Failed or failing TCM hardware
- Network bus problems (termination, excessive bus load, noise/EMI)
Symptoms
- Transmission may enter limp-home mode or default shift strategy (depends on vehicle)
- MIL/CEL or transmission warning lamp illuminated
- Loss of shift control or abnormal shifting behavior
- Other modules reporting U-codes or loss of communication with TCM
- Stored freeze frame or snapshot with unexpected message values
What to check
- Read all stored and pending codes from all modules; note freeze frame data and module IDs
- Verify battery voltage is within specification (with key on and engine off and during cranking)
- Inspect TCM connector and harness for damage, corrosion, or water intrusion
- Check for other U-codes that indicate network-wide or related-module problems
- Attempt communication with the TCM using a factory-level or bi-directional scan tool
- Capture CAN/LIN bus traffic with a capable scan tool or oscilloscope and look for missing, malformed, or out-of-range frames
Signal parameters
- TCM message IDs and expected periodic rates (e.g., gear selection, shift request, torque converter command) — verify presence and frequency
- Message payload fields: gear position, requested gear, transmission torque request, line pressure, lockup status — verify ranges and data format
- Message counters and checksums/CRC — verify counter increments and correct CRC
- CAN bus physical layer: CAN_H/CAN_L idle and dominant voltages, differential waveform integrity
- Network timing: expected message intervals and latency (missed or jittered messages may trigger U0402)
Diagnostic algorithm
- Record all current and pending U-codes and related freeze-frame information from every control module.
- Verify battery condition and charging system; ensure stable nominal system voltage during diagnostics.
- Visually inspect TCM connector, pins, and wiring for corrosion, bent pins, abrasion, or water; repair any damage.
- With a scan tool, attempt to communicate directly with the TCM. Note whether the TCM responds and which PIDs/messages are available.
- Capture live CAN traffic while operating the vehicle or cycling ignition. Look for TCM-originated frames with malformed data, incorrect counter/CRC, or irregular timing.
- Wiggle test harness and connectors while monitoring the bus for changes in traffic or new codes to reveal intermittent faults.
- Measure CAN_H/CAN_L idle voltages and use an oscilloscope to inspect waveforms for noise, reflections, or missing dominant/recessive transitions. Check termination resistance across bus.
- If a replacement TCM was recently installed, confirm correct part number, programming, and module coding. Reflash or update TCM software per manufacturer procedures if available.
- If physical layer and configuration are correct but invalid data persists, consider bench-testing or swapping the TCM (if a known good unit is available) to confirm module failure.
- After repairs, clear codes and perform a road test while monitoring for reappearance of U0402 and related codes. Verify normal transmission operation and that all expected TCM messages are valid.
Likely causes
- Loose or corroded connector pins at the TCM or at a splice in the CAN wiring
- Low battery voltage or bad battery/charging causing data corruption
- Recent repair or module replacement where the TCM was not programmed to vehicle
- Intermittent CAN physical layer fault (short to power/ground, high resistance)
- TCM internal failure producing incorrect frames or bad checksum/counter
Fault status
Status
Invalid data received from the Transmission Control Module (TCM). The receiving module detected message contents, format, checksum, counter, or timing that did not match expected values. Diagnostic data (freeze frame, message dump) should indicate offending frame and source module ID.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
Similar codes
Your 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
Code
U0402
LAND ROVER
U — Network/User
Invalid data received from the transmission control module
Views:
UK: 6
EN: 28
RU: 30
AI status
Completed
Completed
100%
Causes
- Corrupted or malformed CAN/LIN messages from the TCM
- Faulty or intermittent wiring/connector between TCM and network
- Poor power or ground to the TCM causing communication errors
- Software/firmware mismatch, incomplete programming, or corrupted TCM calibration
- Failed or failing TCM hardware
- Network bus problems (termination, excessive bus load, noise/EMI)
Symptoms
- Transmission may enter limp-home mode or default shift strategy (depends on vehicle)
- MIL/CEL or transmission warning lamp illuminated
- Loss of shift control or abnormal shifting behavior
- Other modules reporting U-codes or loss of communication with TCM
- Stored freeze frame or snapshot with unexpected message values
What to check
- Read all stored and pending codes from all modules; note freeze frame data and module IDs
- Verify battery voltage is within specification (with key on and engine off and during cranking)
- Inspect TCM connector and harness for damage, corrosion, or water intrusion
- Check for other U-codes that indicate network-wide or related-module problems
- Attempt communication with the TCM using a factory-level or bi-directional scan tool
- Capture CAN/LIN bus traffic with a capable scan tool or oscilloscope and look for missing, malformed, or out-of-range frames
Signal parameters
- TCM message IDs and expected periodic rates (e.g., gear selection, shift request, torque converter command) — verify presence and frequency
- Message payload fields: gear position, requested gear, transmission torque request, line pressure, lockup status — verify ranges and data format
- Message counters and checksums/CRC — verify counter increments and correct CRC
- CAN bus physical layer: CAN_H/CAN_L idle and dominant voltages, differential waveform integrity
- Network timing: expected message intervals and latency (missed or jittered messages may trigger U0402)
Diagnostic algorithm
- Record all current and pending U-codes and related freeze-frame information from every control module.
- Verify battery condition and charging system; ensure stable nominal system voltage during diagnostics.
- Visually inspect TCM connector, pins, and wiring for corrosion, bent pins, abrasion, or water; repair any damage.
- With a scan tool, attempt to communicate directly with the TCM. Note whether the TCM responds and which PIDs/messages are available.
- Capture live CAN traffic while operating the vehicle or cycling ignition. Look for TCM-originated frames with malformed data, incorrect counter/CRC, or irregular timing.
- Wiggle test harness and connectors while monitoring the bus for changes in traffic or new codes to reveal intermittent faults.
- Measure CAN_H/CAN_L idle voltages and use an oscilloscope to inspect waveforms for noise, reflections, or missing dominant/recessive transitions. Check termination resistance across bus.
- If a replacement TCM was recently installed, confirm correct part number, programming, and module coding. Reflash or update TCM software per manufacturer procedures if available.
- If physical layer and configuration are correct but invalid data persists, consider bench-testing or swapping the TCM (if a known good unit is available) to confirm module failure.
- After repairs, clear codes and perform a road test while monitoring for reappearance of U0402 and related codes. Verify normal transmission operation and that all expected TCM messages are valid.
Likely causes
- Loose or corroded connector pins at the TCM or at a splice in the CAN wiring
- Low battery voltage or bad battery/charging causing data corruption
- Recent repair or module replacement where the TCM was not programmed to vehicle
- Intermittent CAN physical layer fault (short to power/ground, high resistance)
- TCM internal failure producing incorrect frames or bad checksum/counter
Fault status
Status
Invalid data received from the Transmission Control Module (TCM). The receiving module detected message contents, format, checksum, counter, or timing that did not match expected values. Diagnostic data (freeze frame, message dump) should indicate offending frame and source module ID.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
Similar codes
Workshop Manuals
Repair manuals for LAND ROVER
1
Land Rover Defender Workshop Manual 1999-2002 MY
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
Code
U0402
OPEL
U — Network/User
Invalid Signal from TCM (Transmission Control Module)
Views:
UK: 5
EN: 18
RU: 24
AI status
Completed
Completed
100%
Causes
- Corrupted or malformed CAN/LIN messages from the TCM
- Faulty or intermittent wiring/connector between TCM and network
- Poor power or ground to the TCM causing communication errors
- Software/firmware mismatch, incomplete programming, or corrupted TCM calibration
- Failed or failing TCM hardware
- Network bus problems (termination, excessive bus load, noise/EMI)
Symptoms
- Transmission may enter limp-home mode or default shift strategy (depends on vehicle)
- MIL/CEL or transmission warning lamp illuminated
- Loss of shift control or abnormal shifting behavior
- Other modules reporting U-codes or loss of communication with TCM
- Stored freeze frame or snapshot with unexpected message values
What to check
- Read all stored and pending codes from all modules; note freeze frame data and module IDs
- Verify battery voltage is within specification (with key on and engine off and during cranking)
- Inspect TCM connector and harness for damage, corrosion, or water intrusion
- Check for other U-codes that indicate network-wide or related-module problems
- Attempt communication with the TCM using a factory-level or bi-directional scan tool
- Capture CAN/LIN bus traffic with a capable scan tool or oscilloscope and look for missing, malformed, or out-of-range frames
Signal parameters
- TCM message IDs and expected periodic rates (e.g., gear selection, shift request, torque converter command) — verify presence and frequency
- Message payload fields: gear position, requested gear, transmission torque request, line pressure, lockup status — verify ranges and data format
- Message counters and checksums/CRC — verify counter increments and correct CRC
- CAN bus physical layer: CAN_H/CAN_L idle and dominant voltages, differential waveform integrity
- Network timing: expected message intervals and latency (missed or jittered messages may trigger U0402)
Diagnostic algorithm
- Record all current and pending U-codes and related freeze-frame information from every control module.
- Verify battery condition and charging system; ensure stable nominal system voltage during diagnostics.
- Visually inspect TCM connector, pins, and wiring for corrosion, bent pins, abrasion, or water; repair any damage.
- With a scan tool, attempt to communicate directly with the TCM. Note whether the TCM responds and which PIDs/messages are available.
- Capture live CAN traffic while operating the vehicle or cycling ignition. Look for TCM-originated frames with malformed data, incorrect counter/CRC, or irregular timing.
- Wiggle test harness and connectors while monitoring the bus for changes in traffic or new codes to reveal intermittent faults.
- Measure CAN_H/CAN_L idle voltages and use an oscilloscope to inspect waveforms for noise, reflections, or missing dominant/recessive transitions. Check termination resistance across bus.
- If a replacement TCM was recently installed, confirm correct part number, programming, and module coding. Reflash or update TCM software per manufacturer procedures if available.
- If physical layer and configuration are correct but invalid data persists, consider bench-testing or swapping the TCM (if a known good unit is available) to confirm module failure.
- After repairs, clear codes and perform a road test while monitoring for reappearance of U0402 and related codes. Verify normal transmission operation and that all expected TCM messages are valid.
Likely causes
- Loose or corroded connector pins at the TCM or at a splice in the CAN wiring
- Low battery voltage or bad battery/charging causing data corruption
- Recent repair or module replacement where the TCM was not programmed to vehicle
- Intermittent CAN physical layer fault (short to power/ground, high resistance)
- TCM internal failure producing incorrect frames or bad checksum/counter
Fault status
Status
Invalid data received from the Transmission Control Module (TCM). The receiving module detected message contents, format, checksum, counter, or timing that did not match expected values. Diagnostic data (freeze frame, message dump) should indicate offending frame and source module ID.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
Similar codes
Your 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