SCP (J1850) Invalid or Missing Data for Primary Id
Your vehicle's network communication system isn't receiving required data from a module on the SCP bus—think of it like a missing phone call in a group conversation. The ECU expects specific identification data packets but they're either corrupted or not arriving at all.
The ECM monitors the SCP (J1850) data bus for valid primary ID headers from connected modules at regular intervals. When expected message IDs fail to arrive within the timing window or contain invalid checksums, the ECU sets this fault. The bus operates at 41.6 kbps with strict protocol requirements.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Primary ID Message Arrival | Valid ID received within 100-200ms intervals | Missing or invalid ID data for >2 consecutive cycles |
| Data Checksum | CRC matches expected value | Checksum mismatch or corrupted frame |
Code U1062 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, U1062 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.