What Does U1233 Mean?
Secondary communication error for navigation system data on the SCP network. This code typically indicates intermittent or ongoing failure of navigation data transmission between modules.
Common Causes
35%
Intermittent navigation module connector connection or corroded terminals
30%
GPS antenna or receiver circuit fault preventing valid data generation
20%
Software incompatibility between navigation module and other network modules
15%
SCP bus network interference or electrical noise from aftermarket accessories
Diagnostic Steps
1
Step 1: Check GPS antenna connection and verify antenna has clear view of sky
2
Step 2: Perform wiggle test on navigation module connector while monitoring for code reset
3
Step 3: Disconnect aftermarket electrical accessories to test for network interference
4
Step 4: Use manufacturer diagnostic software to check module software versions and compatibility
5
Step 5: Test GPS receiver output signal or replace navigation module if all else checks good
Estimated Repair Cost
$180 - $1,300
Parts + labor, varies by vehicle and location
Secondary communication error for navigation system data on the SCP network. This code typically indicates intermittent or ongoing failure of navigation data transmission between modules.
The most common cause of U1233 (SCP (J1850) Invalid or Missing Data for Navigation) is: Intermittent navigation module connector connection or corroded terminals
Typical repair costs for U1233 range from $180 to $1,300, depending on the vehicle, location, and whether you do it yourself or go to a shop.
No safety impact. Navigation system may provide incorrect or no routing information but does not affect vehicle safety features.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U1233 to identify the root cause.
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Quick Info
Category
Network
System
Infotainment/Navigation Network
Difficulty
Type
Manufacturer
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