SCP (J1850) Invalid or Missing Data for Experimental #3
Your vehicle's communication network (SCP bus) is missing or receiving corrupted data from an experimental module. Think of it like a radio station that's supposed to broadcast but either isn't transmitting or the signal is too garbled to understand.
The ECU monitors the SCP (J1850) bus for valid data packets from experimental module #3. It validates message structure, checksums, and timing intervals. If data arrives corrupted, too late, or not at all for a specified duration, the fault is triggered.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| SCP Bus Message Validity | Valid message received within 100ms intervals with correct checksum | Missing message or invalid checksum detected for >2 consecutive cycles |
| Data Integrity Check | All bits and CRC validation pass | CRC mismatch or corrupted payload detected |
Code U1153 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, U1153 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.