SCP (J1850) Invalid or Missing Data for Function Read Vehicle Speed
Your vehicle's computer isn't receiving valid speed data over the SCP communication network, similar to a radio losing its signal. This prevents the ECU from knowing how fast you're driving, which affects multiple engine and transmission functions.
The ECU monitors the SCP (J1850) bus for valid Vehicle Speed (VSS) data transmitted from the instrument cluster or ABS module. It expects periodic speed messages within specific time intervals with valid checksums and data ranges. If messages are missing, corrupted, or arrive outside expected timing windows, the fault is triggered.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| SCP Message Interval | Received every 100-200ms | Missing or delayed >500ms |
| VSS Data Range | 0-255 km/h valid format | Invalid checksum or out-of-range values |
Code U1341 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, U1341 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.