What Does U1189 Mean?
This code indicates a different Primary ID module on the SCP J1850 network is not communicating properly or data is missing. This represents a second module communication fault distinct from U1188.
Common Causes
35%
Failed or intermittent control module on the network
30%
Loose or corroded ground connections affecting module operation
25%
Network bus circuit fault (open, short, or high resistance)
10%
Insufficient power supply to affected module
Diagnostic Steps
1
Step 1: Verify battery and charging system voltage under all conditions
2
Step 2: Use enhanced scan tool to identify the specific module (Primary ID) failing to communicate
3
Step 3: Check power and ground circuits to the identified module with DVOM
4
Step 4: Inspect module connector for bent pins, corrosion, or moisture intrusion
5
Step 5: Monitor SCP bus signal with oscilloscope for proper 41.6 kbps PWM signal
Estimated Repair Cost
$150 - $1,200
Parts + labor, varies by vehicle and location
This code indicates a different Primary ID module on the SCP J1850 network is not communicating properly or data is missing. This represents a second module communication fault distinct from U1188.
The most common cause of U1189 (SCP (J1850) Invalid or Missing Data for Primary Id) is: Failed or intermittent control module on the network
Typical repair costs for U1189 range from $150 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Depending on the affected module, safety systems may be compromised. Vehicle operation may be significantly impacted if critical modules cannot communicate.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U1189 to identify the root cause.
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Quick Info
Category
Network
System
Network Communication
Difficulty
Type
Manufacturer
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