SCP (J1850) Invalid or Missing Data for Time / Date
Your vehicle's computer can't receive or read the correct time and date information from the communication network, like a clock that stopped working on your dashboard. This prevents the ECU from properly logging diagnostic data and timestamps for other systems.
The ECU monitors the SCP (J1850) bus for valid time/date messages from the body control module or gateway. It checks for message presence, data integrity, and proper CAN/SCP protocol compliance. If the timestamp data is corrupted, missing, or fails checksum validation, the fault is triggered.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| SCP Time/Date Message Presence | Valid message received every 100-500ms | Message missing, corrupted, or invalid for >2 seconds |
| Data Integrity Checksum | Checksum passes validation | Checksum mismatch detected |
Code U1249 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, U1249 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.