What Does U1023 Mean?
Another instance of missing primary ID data on the SCP network, typically involving a different module or circuit than U1022. Multiple communication faults suggest widespread network problems.
Common Causes
35%
Open circuit or high resistance in SCP bus wiring
30%
Failed anti-lock brake module or transmission control module
20%
Poor power distribution to multiple control modules
15%
Water intrusion or corrosion in module connectors
Diagnostic Steps
1
Step 1: Perform network integrity test using scan tool to map all module responses
2
Step 2: Check for blown fuses or tripped circuit breakers in power distribution center
3
Step 3: Inspect firewall pass-through areas for damaged or pinched harnesses
4
Step 4: Test voltage drop on SCP bus lines during high communication traffic periods
5
Step 5: Clear codes and monitor which codes return first to identify primary failure point
Estimated Repair Cost
$150 - $1,100
Parts + labor, varies by vehicle and location
Another instance of missing primary ID data on the SCP network, typically involving a different module or circuit than U1022. Multiple communication faults suggest widespread network problems.
The most common cause of U1023 (SCP (J1850) Invalid or Missing Data for Primary Id) is: Open circuit or high resistance in SCP bus wiring
Typical repair costs for U1023 range from $150 to $1,100, depending on the vehicle, location, and whether you do it yourself or go to a shop.
May affect safety systems like ABS or traction control if those modules cannot communicate. Monitor warning lights carefully.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U1023 to identify the root cause.
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Quick Info
Category
Network
System
Network Communication / Multiple Systems
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
