What Does U1049 Mean?
Similar to U1048, this code indicates the module cannot receive valid primary identification data over the SCP J1850 network. Multiple U104X codes often indicate widespread network communication failure.
Common Causes
35%
Damaged SCP bus wiring harness or connectors
30%
Failed body control module or generic electronic module (GEM)
20%
Insufficient power supply voltage to network modules
10%
Defective instrument cluster
5%
Short circuit on SCP bus from aftermarket accessories
Diagnostic Steps
1
Step 1: Verify stable battery voltage (12V+) and check all main power distribution fuses
2
Step 2: Disconnect any aftermarket devices (alarm, remote start, stereo) to rule out bus interference
3
Step 3: Monitor live data stream to determine which modules are offline or sending invalid data
4
Step 4: Test SCP bus signal integrity with oscilloscope (should see clean 0-7V square wave patterns at ~41.6 kbps)
5
Step 5: Isolate problem by disconnecting modules one at a time to identify if one is pulling down the bus
Estimated Repair Cost
$150 - $900
Parts + labor, varies by vehicle and location
Similar to U1048, this code indicates the module cannot receive valid primary identification data over the SCP J1850 network. Multiple U104X codes often indicate widespread network communication failure.
The most common cause of U1049 (SCP (J1850) Invalid or Missing Data for Primary Id) is: Damaged SCP bus wiring harness or connectors
Typical repair costs for U1049 range from $150 to $900, depending on the vehicle, location, and whether you do it yourself or go to a shop.
May cause multiple system failures including gauges, lighting, or engine management. Vehicle operation may be compromised depending on which modules are affected.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U1049 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Network
System
Vehicle Communication Network
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
