What this code means
U0199 may indicate that the power seat control unit is not receiving expected communication from the power window master switch on the body communication network.
What the vehicle may do
- The vehicle may show power seat or body-electrical behavior that seems intermittent or unavailable.
- The code can appear when the power window master switch does not start up normally.
- Other body-network symptoms may be possible if the concern is broader than one module.
Possible fault areas
- Possible power or ground circuit concern for the power window master switch.
- Possible power window master switch startup or communication concern.
- Possible B-CAN body-network communication concern between the involved control units.
Diagnostic path
Opening context
For this 2020 to 2025 Honda CR-V Hybrid, U0199 is a network communication code. In plain language, the power seat control unit may not be getting the expected communication from the power window master switch over the body network. The vehicle may have power seat or related body-electrical behavior that seems inconsistent, and the broad fault areas can include the power window master switch not starting up normally, a possible power or ground issue to that switch, or a B-CAN communication problem. Start with the basic system checks and follow a structured diagnostic approach before chasing individual parts.
Prioritize the network path
If you are troubleshooting more than one code, do not treat U0199 in isolation. Work through the multiple-code B-CAN diagnostic path first, so you know whether this is part of a wider body-network communication issue or a more focused concern between the power seat control unit and the power window master switch.
Check the switch feed before going deeper
Before continuing with this U0199 path, make sure the power and ground circuits for the power window master switch are checked first. This code may set if that switch does not start normally, and a feed or ground problem can make the power seat control unit lose the data it expects from the switch.
Run the confirmation step
Now turn the vehicle to the ON mode. Once it is in ON mode, wait for at least 6 seconds. That gives the communication fault a chance to show up under the intended operating condition.
If the path stops short
The available diagnostic path does not provide the next detailed B-CAN test steps or data-list values for this code. If you reach that point, pause, recheck the earlier diagnostic path, and avoid guessing. Keep the verification separate from the testing: after any correction, bring the vehicle back to ON mode, allow the monitor time to run, and confirm U0199 stays gone. Bottom line: prove the power window master switch can power up and communicate before condemning anything else. For more diagnostic training, visit stepdiagnostics.com.
Final check
For U0199, first separate a power or ground startup problem at the power window master switch from a true B-CAN communication problem.
For more guided automotive diagnostics, visit STEP Diagnostics.
