What Does U1135 Mean?
This code is a related identifier for invalid or missing ignition switch and starter data on the SCP network. It typically indicates a different module detecting the same communication issue as U1134 or represents a secondary failure mode.
Common Causes
30%
Body Control Module not broadcasting ignition status
25%
Ignition switch position sensor failure
20%
SCP network wiring fault or connector corrosion
15%
Starter relay or circuit providing invalid feedback
10%
Instrument cluster or receiving module failure
Diagnostic Steps
1
Step 1: Identify which specific module set U1135 to determine the data recipient with the issue
2
Step 2: Compare ignition switch status between BCM and PCM scan tool data for discrepancies
3
Step 3: Test starter relay operation and feedback circuit during cranking cycle
4
Step 4: Perform voltage drop test on ignition switch power and signal circuits
5
Step 5: Check for TSBs related to BCM software updates for ignition signal processing
Estimated Repair Cost
$200 - $800
Parts + labor, varies by vehicle and location
This code is a related identifier for invalid or missing ignition switch and starter data on the SCP network. It typically indicates a different module detecting the same communication issue as U1134 or represents a secondary failure mode.
The most common cause of U1135 (SCP (J1850) Invalid or Missing Data for Ignition Switch / Starter) is: Body Control Module not broadcasting ignition status
Typical repair costs for U1135 range from $200 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Can result in starting system failures, security system malfunctions, or improper accessory operation. Vehicle may fail to recognize key position changes.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U1135 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
Network Communication / Ignition System
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
