A 2019 Toyota RAV4 V arrived in the bay with a tailgate that refused to open or close, emitting only a warning beep when the button was pressed. The scanner pulled three codes simultaneously: B2227, B2226, and B2251.
The Trap of Isolated Fault Codes
These codes indicate faults with the right pulse sensor (B2227), the left pulse sensor (B2226), and the closing switch (B2251). If you look at these one by one, you might start ordering parts. Spindle actuators for the RAV4 are expensive, and replacing the latch mechanism takes time. The vehicle locks up the operation and sounds the buzzer to protect the system. However, losing both pulse sensors and the closer switch at the exact same moment is highly unlikely to be three simultaneous component failures.
Tracing the Common Circuit
The diagnostic platform we build analyzed this specific combination and ranked a wiring harness break at the tailgate hinge bellows as the 85 percent probable cause. On the XA50 RAV4, the wiring for both power spindle actuators and the latch closing switch runs through the flexible rubber boot at the top of the hatch. Repeated opening bends these wires. When the shared sensor power or ground breaks, the Multiplex Network Door ECU instantly loses signal from all three components.
The recommended testing starts with a visual inspection and a pull test of the wires inside that rubber boot. A simple continuity check between the door ECU connector and the tailgate connectors, along with a shake test during movement, confirms the break without tearing apart the interior trims.
Ruling Out the Door Module
The second most likely cause, ranked at 65 percent, was an internal fault or voltage drop at the Multiplex Network Door ECU itself. If the module has a damaged internal power converter or microprocessor, it cannot supply reference voltage to the pulse sensors or read the latch switch. Checking this requires measuring the main +12V battery and ignition feed, plus chassis ground, directly at connector R27. Technicians can also inspect for moisture or corrosion on the board.
Further down the list were the closer switch itself at 50 percent and the spindle actuators at 45 percent. Testing those involves reading live data for the half-latch status or putting an oscilloscope on pins DS12 and DS22 to check the digital pulse trains.
Next Steps for Your Bay
When multiple components on the same circuit drop out at once, look for the physical bottleneck they share. Are you seeing similar grouped codes on Toyota power tailgates, or do your technicians normally test each actuator individually?