What Does U1002 Mean?
Another SCP network communication fault indicating a different module or data parameter is not being received correctly. When U1000, U1001, and U1002 appear together, this strongly suggests a network infrastructure problem.
Common Causes
35%
Widespread corrosion or water damage in network wiring harness
30%
Damaged SCP bus termination resistor or network topology issue
25%
Failed module creating bus contention or signal interference
7%
Inadequate ground distribution to multiple modules
3%
Manufacturing defect in vehicle wiring harness
Diagnostic Steps
1
Step 1: Create a network map identifying all modules setting U-codes to visualize affected systems
2
Step 2: Measure voltage on SCP+ and SCP- bus lines with key on, engine off (should show characteristic mid-range voltage)
3
Step 3: Disconnect battery and check continuity of SCP bus wiring from DLC to each affected module
4
Step 4: Systematically disconnect module connectors starting with accessories, testing bus function after each disconnection
5
Step 5: If network is restored by disconnecting a module, inspect that module and its wiring in detail before replacement
Estimated Repair Cost
$200 - $2,000
Parts + labor, varies by vehicle and location
Another SCP network communication fault indicating a different module or data parameter is not being received correctly. When U1000, U1001, and U1002 appear together, this strongly suggests a network infrastructure problem.
The most common cause of U1002 (SCP (J1850) Invalid or Missing Data for Primary Id) is: Widespread corrosion or water damage in network wiring harness
Typical repair costs for U1002 range from $200 to $2,000, depending on the vehicle, location, and whether you do it yourself or go to a shop.
May disable multiple vehicle systems unpredictably. Warning lights may not function properly. Consider vehicle potentially unreliable until repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U1002 to identify the root cause.
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Quick Info
Category
Network
System
Vehicle Communication Network
Difficulty
Type
Manufacturer
Recommended Tools
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