Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC U0199: Keyless Access Control Unit Lost Communication With Door Multiplex Control Unit
- Clear the DTCs with the HDS.
- Press the engine start/stop button to select the OFF, ACC, and ON mode.
- Wait for at least 6 seconds.
- Check for DTCs with the HDS.
Is DTC U0199 indicated?
YES - Go to step 5.
NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections between the keyless access control unit and the door multiplex control unit.
- From the BODY ELECTRICAL SYSTEM SELECT menu, select B- CAN CONTROL UNITS INFORMATION, and then select CHECK CONNECTED CONTROL UNITS.
Is the power window unit detected?
YES - Go to step 9.
NO - Go to step 6.
- Measure the voltage between body ground and power window master switch 37P connector terminal No. 13.Fig 1: Measuring Voltage Between Body Ground And Power Window Master Switch 37P Connector Terminal No. 13 With Connector End View
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES - Go to step 8.
NO - Go to step 7.
- Check the No. 15(10 A) fuse in the under- hood fuse/relay box.
Is the fuse OK?
YES - Repair an open or high resistance in the No. 15 (10 A) fuse circuit.
NO - Replace the fuse. If the fuse blows again, repair a short to ground in the No. 15 (10 A) fuse circuit.
- Measure the voltage between body ground and power window master switch 37P connector terminals No. 32 and No. 37 individually.Fig 2: Measuring Voltage Between Body Ground And Power Window Master Switch 37P Connector Terminals No. 32 And No. 37 Individually
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there less than 0.2 V?
YES - Go to step 9.
NO - Repair an open or high resistance in the ground wire or poor ground (G401) and/or (G402).
- Press the engine start/stop button to select the OFF mode.
- Disconnect the power window master switch 37P connector.
- Disconnect power tailgate control unit connector B (32P).
- Check for continuity between power window master switch 37P connector terminals No. 33 and No. 35 and keyless access control unit connector B (32P) terminals No. 7 and No. 6 respectively.Fig 3: Checking Continuity Between Power Window Master Switch 37P Connector Terminals And Keyless Access Control Unit Connector B (32P) Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Replace the power window master switch (see REAR POWER WINDOW SWITCH TEST ).
NO - Repair an open or poor connection in the B- CAN wire between the keyless access control unit and the door multiplex control unit.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.