SCP (J1850) Invalid or Missing Data for Door Locks
Your vehicle's communication network isn't receiving door lock status information from the door lock control module. Think of it like a radio station that's supposed to broadcast but the signal isn't coming through.
The Body Control Module (BCM) monitors the SCP (J1850) serial communication bus for door lock status messages from the door lock actuator control module. It expects valid data packets at regular intervals; if messages are missing, corrupted, or fail checksum validation for a defined period, the fault triggers.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| SCP Message Presence | Valid door lock status received every 100-500ms | No valid message received for >2 seconds or checksum failure |
| Data Integrity | Message checksum passes validation | Checksum mismatch or corrupted data frame |
Code U1196 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, U1196 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.