SCP Bus Invalid Data Code U1112
Code U1112 indicates that a control module has detected invalid or missing data on the SCP (Standard Corporate Protocol) communication bus, which is Ford's proprietary implementation of SAE J1850 running at 41.6 kbps with pulse-width modulation on a single wire. This fault occurs when a module on the network fails to receive the expected primary data identifier, disrupting communication between modules such as the PCM, BCM, ABS, or instrument cluster. The lack of valid data can stem from a faulty transmitting module, bus wiring issues, or corrupted data frames.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty control module that transmits the primary identifier (PCM, BCM, or other)
- Open or short circuit in the SCP bus wiring (SCP+ and SCP- circuits)
- Bus termination resistor out of specification or damaged
- Electromagnetic interference corrupting bus signals
- Internal failure of the communication transceiver in a connected module
- Low voltage or power supply failure to modules on the SCP network
- Corroded, loose, or damaged connectors on the communication bus
3. Symptoms You Will Notice
- Check Engine Light or other warning lights illuminated
- Erratic behavior or intermittent failure of multiple systems (e.g., gauges, transmission, ABS)
4. Step-by-Step Diagnosis
Scan all modules for related communication codes and freeze frame data
Visually inspect SCP bus wiring and connectors for damage, corrosion, or loose connections
Measure bus voltage and resistance at the data link connector (DLC) and compare to specifications
Check termination resistors (typically 120 ohms) at each end of the bus
Isolate the fault by disconnecting modules one at a time while monitoring bus activity
Perform a network integrity test using a scope or advanced scan tool
5. Frequently Asked Questions
Is it safe to drive?▼
The vehicle may still be drivable, but you may experience drivability issues or loss of some functions. It is recommended to diagnose and repair the fault promptly to avoid further problems.
How much does it cost to fix?▼
Diagnosis typically costs $100-$200. Repairs can range from $50 for a loose connector to $500 or more for a faulty module, depending on the root cause.