What this code means
U0038 may indicate that the Integrated Control Module is seeing a communication problem on the DF-CAN B network.
What the vehicle may do
- The vehicle may show warning messages or indicator lights.
- Communication-related symptoms may be present.
- The vehicle can sometimes have no obvious driveability complaint.
Possible fault areas
- Possible network communication path concern.
- Possible connector or wiring concern.
- Possible module communication behavior concern.
Diagnostic path
Opening context
U0038 on this 2020 to 2025 Honda CR-V Hybrid is a communication fault tied to the ICM, or Integrated Control Module. In plain terms, the module may not be getting a clean message out over the DF-CAN B network. The vehicle may show warning messages, communication-related symptoms, or sometimes no obvious driveability complaint. Broadly, possible fault areas can include the network communication path, connectors, wiring, or module communication behavior. For this code, keep the diagnosis focused and do not jump straight to parts.
Start with the basic checks
Before working the U0038 check itself, start with the basic system checks and follow a structured diagnostic approach. Make sure the concern is being handled in an orderly way before you move into the code confirmation step.
Confirm the code conditions
Next, turn the vehicle to ON mode and wait 6 seconds. That wait time matters, because this is the confirmation window given for the check. The code logic is straightforward: if the ICM cannot send a signal to the other unit through DF-CAN B, it decides there is an abnormal condition and stores U0038.
When the path moves into bus-off diagnosis
From there, the diagnostic path points toward ICM bus-off troubleshooting. If that complete path is not available in the workflow you are using, pause, recheck the earlier diagnostic path, and avoid guessing. Stay with the network diagnosis until the communication fault is actually proven.
Takeaway
The takeaway for U0038 is simple: confirm the code under the correct key-on condition, understand that the ICM is flagging a DF-CAN B communication problem, and keep the next steps structured around bus communication rather than parts swapping. For more diagnostic training, visit stepdiagnostics.com.
Final check
U0038 should be approached as a possible network communication issue, with the diagnostic focus kept on confirming the condition and following the communication-fault path.
For more guided automotive diagnostics, visit STEP Diagnostics.
