SCP (J1850) Invalid or Missing Data for Electrical Energy Management
Your vehicle's electrical power management system isn't communicating properly with the engine computer. It's like a manager not receiving status updates from a team member about available resources.
The ECM monitors SCP (J1850) bus messages from the Electrical Energy Management module to track available electrical power, battery voltage, and alternator output. It uses this data to adjust fuel injection timing and load management. Missing or corrupted messages trigger this fault when communication timeouts exceed threshold duration.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| SCP Bus Message Timeout | Valid message every 10-100ms | No valid message for >500ms |
| Battery Voltage Data Validity | 9.0-16.0V with valid checksum | Invalid checksum or voltage implausible |
Code U1117 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, U1117 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.