What Does U1145 Mean?
The final in this series of primary ID communication faults on the SCP J1850 network. This represents yet another module address that is not broadcasting valid data.
Common Causes
35%
Defective generic electronic module (GEM) or smart junction box
28%
Failed vehicle security module or passive anti-theft system (PATS)
22%
Water damage to module or connectors
15%
Multiple module failure due to voltage spike or electrical surge
Diagnostic Steps
1
Step 1: Determine which module Primary ID corresponds to U1145 using factory service information
2
Step 2: Check for water leaks or moisture in module location (common in floor-mounted modules)
3
Step 3: Test for proper power and ground at the non-communicating module connector
4
Step 4: If multiple U-codes are present, check for recent electrical work or jump-start events that may have caused surge damage
5
Step 5: Replace confirmed faulty module and clear codes; monitor for recurrence
Estimated Repair Cost
$200 - $1,000
Parts + labor, varies by vehicle and location
The final in this series of primary ID communication faults on the SCP J1850 network. This represents yet another module address that is not broadcasting valid data.
The most common cause of U1145 (SCP (J1850) Invalid or Missing Data for Primary Id) is: Defective generic electronic module (GEM) or smart junction box
Typical repair costs for U1145 range from $200 to $1,000, depending on the vehicle, location, and whether you do it yourself or go to a shop.
May prevent vehicle starting if security module is affected. Other impacts vary by specific module but generally do not prevent safe operation.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U1145 to identify the root cause.
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Quick Info
Category
Network
System
Communication Network
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
