SCP (J1850) Invalid or Missing Data for Remote Button Control
Your vehicle's communication network isn't receiving button control signals from the remote (like keyless entry or steering wheel controls). It's like a radio losing the signal from the transmitter.
The ECU monitors the J1850 serial communication bus for valid data packets from remote control modules. It checks for proper message formatting, timing, and signal integrity from wireless receivers and steering wheel control switches. When expected data frames fail to arrive within specified intervals, the fault is triggered.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| J1850 Message Valid Signal | Valid data frames received every 50-100ms | Missing or corrupted frames for >500ms |
| Remote Button Data Integrity | CRC checksum valid, correct message structure | Checksum error or malformed packet detected |
Code U1173 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, U1173 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.