What Does U1090 Mean?
This code indicates the module storing this fault is not receiving expected data messages over the SCP (Standard Corporate Protocol) J1850 communication bus for non-legislated diagnostic functions. Communication breakdown between modules prevents sharing of non-emission related diagnostic information.
Common Causes
35%
Faulty or corroded module connector/pins on communicating module
30%
Open or short circuit in SCP bus wiring between modules
20%
Failed sending module not transmitting data
10%
Poor ground connection at module or bus termination
5%
Aftermarket accessory interfering with bus communication
Diagnostic Steps
1
Step 1: Identify which module set this code and determine which module(s) should be sending the missing data using factory wiring diagrams
2
Step 2: Using a scan tool with bus monitoring capability, observe live SCP bus traffic to verify communication activity and message IDs
3
Step 3: Inspect all connectors on the affected modules for corrosion, bent pins, or moisture intrusion
4
Step 4: Check SCP bus wiring continuity and resistance between communicating modules (should be approximately 100-120 ohms across bus)
5
Step 5: Verify power and ground circuits to all affected modules, test module operation if wiring checks pass
Estimated Repair Cost
$150 - $800
Parts + labor, varies by vehicle and location
This code indicates the module storing this fault is not receiving expected data messages over the SCP (Standard Corporate Protocol) J1850 communication bus for non-legislated diagnostic functions. Communication breakdown between modules prevents sharing of non-emission related diagnostic informatio...
The most common cause of U1090 (SCP (J1850) Invalid or Missing Data for Non-Legislated Diagnostics) is: Faulty or corroded module connector/pins on communicating module
Typical repair costs for U1090 range from $150 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may be safe to drive but certain features or convenience functions may not operate correctly. Some diagnostic functions may be unavailable.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U1090 to identify the root cause.
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Quick Info
Category
Network
System
Communication Network
Difficulty
Type
Manufacturer
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