SCP (J1850) Invalid or Missing Data for Electric Traction Drive (Inverter)
Your vehicle's power electronics aren't communicating properly with the main computer over the diagnostic network. Think of it like a phone losing signal between the battery management system and the brain controlling the electric motor.
The ECU monitors serial data messages (SCP/J1850) from the inverter module that relay voltage, current, temperature, and operational status. It expects continuous valid data packets at specific intervals; missing or corrupted messages trigger this fault. The ECU uses checksums and message timing to verify data integrity.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| SCP Message Presence | Valid message received every 10-100ms | Message missing or invalid for >200ms |
| Inverter Data Validity | Checksum match, within operational range | Checksum mismatch or data out of range |
Code U1108 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, U1108 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.