Lost Communication With Power Steering Control Module “B”
U015B concerns lost communication with power steering control module “b”. Learn what this fault indicates and where to begin diagnosis.
What you may notice
Symptoms
- 01System warning may illuminate
- 02Affected feature may be unavailable
- 03Symptoms depend on the vehicle
Where to look first
Common causes
- 01Module power or ground loss, connector or network wiring fault, or a module that stopped communicating
- 02Module power, ground, or connector fault
- 03Vehicle-specific mechanical or control issue
A sensible sequence
Best diagnostic order
- 01Record all available module faults
- 02Scan all accessible modules and record which modules report the communication fault. Check battery voltage, module power and ground, connectors, and network wiring using the vehicle topology.
- 03Compare results with vehicle-specific service information
- 04Verify the repair
Step by step
What to check and repair
- 01Scan all accessible modules and record which modules report the communication fault. Check battery voltage, module power and ground, connectors, and network wiring using the vehicle topology.
- 02Repair the verified cause and rescan all affected modules
Read the signals
Live-data clues
Module communication status and network faults
- Typical behavior
- Consistent with vehicle-specific specifications
- Possible clue
- A missing module or unexpected state helps localize the fault
| Parameter | Typical behavior | What it can suggest |
|---|---|---|
| Module communication status and network faults | Consistent with vehicle-specific specifications | A missing module or unexpected state helps localize the fault |
What U015B means
Lost Communication With Power Steering Control Module “B”. The code identifies a detected condition, not a confirmed failed part. Exact behavior depends on the vehicle and control module.
Diagnostic direction
Scan all accessible modules and record which modules report the communication fault. Check battery voltage, module power and ground, connectors, and network wiring using the vehicle topology.
Before clearing the code
Save all module faults and freeze-frame data where supported. Use service information for the exact vehicle, repair the verified cause, then confirm the warning does not return.