U1002 SCP Communication Fault
The U1002 code indicates a failure in the SCP (Standard Corporate Protocol) J1850-based communication network, specifically invalid or missing data for the primary identifier. This protocol is used in Ford vehicles for communication between electronic modules. The receiving module detected that the message from the transmitting module contains corrupt, incomplete, or improperly formatted data for the primary data identifier, preventing correct interpretation of the information.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty control module transmitting the message (PCM, ABS, instrument cluster, etc.)
- Electromagnetic interference on the SCP data bus
- Abnormal resistance in the SCP bus circuits (circuits 914 and 915 in Ford)
- Poor connections or corrosion in communication bus connectors
- Internal failure of the receiving module that generates the code
- Voltage variation or poor ground in network modules
3. Symptoms You Will Notice
- Check Engine Light or other warning lights illuminated
- Intermittent or complete loss of communication between modules
- Malfunctioning gauges or instrument cluster issues
- Vehicle may experience drivability problems
4. Step-by-Step Diagnosis
Scan for all stored codes and freeze frame data
Inspect SCP bus circuits (914 and 915) for damage, corrosion, or shorts
Check resistance on the SCP bus; typical value is around 60 ohms
Test for voltage and ground at network modules
Isolate the faulty module by disconnecting modules one at a time while monitoring bus activity
5. Frequently Asked Questions
Is it safe to drive?▼
The severity is medium. You can drive short distances, but the vehicle may experience communication issues that could affect drivability or safety. It is recommended to diagnose and repair promptly.
How much does it cost to fix?▼
Diagnosis typically costs $100-$200. Repair costs vary widely: cleaning connectors may be minimal, while replacing a module can range from $200 to $800 or more, depending on the module and labor.