U0208

Code

Generic U — Network/User

Lost Communication With Seat Control Module A

Brand: Generic

Type: U — Network/User

Views: UK: 27 EN: 42 RU: 45

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Page language: EN

Faulty seat control module (internal failure)
Power or ground supply problem to seat control module
Damaged, corroded, or disconnected connector at the seat control module
Open, shorted, or high-resistance wiring on the vehicle data bus (CAN or LIN) to the module
Missing or failed bus termination resistor(s)
Module not configured/programmed or incompatible software

Seat functions (position, memory, heating, ventilation) may be inoperative or intermittent
Seat position memory recall may not work
Relevant dash or seat-related warning lamps or messages
Other modules show related communication errors or reduced functionality
DTC remains stored and may return after clearing

Connect a professional scan tool and confirm U0208 and any additional U-codes; note freeze frame and occurrence frequency
Verify whether the seat control module is present/listed on the vehicle network using the scan tool
Inspect connectors and wiring at the seat control module for corrosion, bent pins, water, or damage
Check fuses and relays supplying the seat module power and ignition circuits
Measure module supply and ground voltages with a DVM (expected nominal 11–14 V with ignition on)
Verify data-bus physical layer: measure bus idle voltages and check termination resistance (approximately 60 ohms across CAN high/low) or LIN single-wire idle level per manufacturer

Network: CAN or LIN depending on vehicle; verify correct bus for seat module in wiring diagram
Expected supply voltage to module: approx. 11–14 V with ignition on
CAN bus idle (recessive) nominal around mid-supply; differential waveform present when transmitting (use scope/ANalyzer)
Typical message cadence: periodic diagnostic/telemetry messages (often 100–1000 ms intervals) — check OEM data for exact intervals/IDs
Termination: correct bus termination (≈60 ohms across CAN high/low) or single-wire LIN pull-up/pull-down per OEM spec

Read and record all DTCs and freeze-frame data with a capable scan tool. Note if U0208 is current or history and any related U- or B- codes.
Verify module presence on the network. Use the scan tool to try to communicate with the seat control module and list its network address or response.
Visually inspect connectors, pins, and harness routing to the seat module (under seat, through trim). Repair obvious damage or corrosion.
Check fuses and measure module battery/ignition supply and ground integrity at the module connector. Repair poor power/ground before further testing.
Measure bus physical layer: check idle voltages and termination resistance. If values are out of range, trace and repair wiring/terminators.
Use an oscilloscope or CAN/LIN bus analyzer to observe traffic. Confirm whether the seat module transmits periodic frames. If no traffic, focus on power/communications wiring.
Perform wiggle and load tests on harnesses while monitoring for changes in communication to find intermittent faults.
If wiring and network are verified good and module still non-responsive, check for module-specific software or configuration faults — verify software/calibration level and reprogram if required by OEM.
Replace the seat control module only after verifying wiring, power, grounds, and bus integrity. Follow OEM programming and initialization procedures after replacement.
Clear codes and perform functional tests to confirm repair; re-scan to ensure U0208 does not return.