U023B: Lost Communication with Image Processing Module B
Diagnostic trouble code U023B indicates a loss of communication between the powertrain control module (PCM) or main control module and the Image Processing Module 'B'. This module processes data from driver-assistance cameras, such as night vision, pedestrian detection, or lane-keeping assist. Communication occurs over the controller area network (CAN bus). When the module fails to receive expected signals from the Image Processing Module 'B' for a set period, this generic fault code is set per SAE J2012.
1. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.
2. Most Common Causes
- Faulty Image Processing Module 'B' (internal damage)
- Open or short circuit in the CAN bus wiring
- Corroded, damaged, or bent pins in the module harness connectors
- Loss of power or ground to the Image Processing Module
- Fault in the main control module (PCM/BCM) that oversees the network
- Electromagnetic interference in the camera wiring
3. Symptoms You Will Notice
- Illuminated check engine light or service camera system warning
- Malfunctioning driver-assistance features (e.g., lane departure warning, night vision, pedestrian detection)
4. Step-by-Step Diagnosis
Scan for other related codes and check for communication faults on the CAN bus.
Inspect the Image Processing Module 'B' connector for corrosion, bent pins, or damage.
Test power and ground circuits at the module; verify voltage and continuity.
Check CAN bus wiring for opens, shorts, or high resistance using a multimeter or oscilloscope.
If wiring is intact, attempt to communicate with the module via a scan tool; if no response, replace the module.
5. Frequently Asked Questions
Is it safe to drive?▼
The vehicle may still be drivable, but driver-assistance features may be disabled. It is recommended to diagnose and repair the issue promptly to restore safety systems.
How much does it cost to fix?▼
Costs vary widely: from $100–$200 for wiring repairs to $500–$1,200+ for module replacement, including labor and programming.