What Does U1106 Mean?
The control module cannot receive valid legislated diagnostics data over the SCP network. This affects emissions-related diagnostic information sharing required for OBD-II compliance and proper system monitoring.
Common Causes
40%
Powertrain Control Module (PCM) communication fault or internal failure
25%
Damaged SCP network wiring between PCM and other diagnostic modules
20%
Failed instrument cluster or gateway module not relaying diagnostic data
10%
PCM software issues or corrupted diagnostic calibration
5%
Network termination resistor failure causing signal reflection
Diagnostic Steps
1
Step 1: Verify PCM is communicating properly; check for additional codes in PCM and confirm it's responding to scan tool commands
2
Step 2: Monitor Mode $06 and diagnostic parameter messages on the network to see which data is missing
3
Step 3: Measure SCP bus resistance and voltage levels at PCM connector; should see approximately 2.5V at rest with proper termination
4
Step 4: Inspect PCM connector for corrosion, moisture, or bent pins affecting communication circuits
5
Step 5: Attempt PCM reflash or software update if communication is present but data format is invalid
Estimated Repair Cost
$150 - $1,500
Parts + labor, varies by vehicle and location
The control module cannot receive valid legislated diagnostics data over the SCP network. This affects emissions-related diagnostic information sharing required for OBD-II compliance and proper system monitoring.
The most common cause of U1106 (SCP (J1850) Invalid or Missing Data for Legislated Diagnostics) is: Powertrain Control Module (PCM) communication fault or internal failure
Typical repair costs for U1106 range from $150 to $1,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may fail emissions testing and monitors may not run properly. Typically safe to drive but emissions compliance is affected.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U1106 to identify the root cause.
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Quick Info
Category
Network
System
OBD-II Emissions Diagnostics
Difficulty
Type
Manufacturer
Recommended Tools
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