SCP (J1850) Invalid or Missing Data for Telltales
Your vehicle's instrument cluster isn't receiving proper communication signals from the engine control unit, like a radio losing its station signal. The ECU can't reliably send telltale (warning light) data over the SCP bus network.
The ECU monitors the SCP (SAE J1850) serial communication bus that transmits telltale status and diagnostic data to the instrument cluster. It validates message timing, data integrity, and signal presence on the network. When valid data frames fail to transmit or receive within expected intervals, the fault is logged.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| SCP Bus Message Frequency | Valid frames received every 10-100ms | Missing or delayed frames exceeding timeout threshold |
| Data Checksum Validity | Checksum matches transmitted data | Checksum mismatch or corrupted payload detected |
Code U1137 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, U1137 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.