B259E Code - Trunk/Liftgate Door Handle Sense Stuck

The Passive Entry (PE) antenna units allow the transmitter within the Radio Frequency Hub (also known as the RF Hub) to communicate via Low Frequency (LF) radio transmission with a Frequency Operated Button with Integrated Key (FOBIK) that is located inside the vehicle or, at most, about 2 meters (6.5 feet) horizontally in all directions around the outside of the vehicle. The RF Hub uses communication through the antenna units to wake up and challenge a FOBIK that is within range in order to authenticate whether that FOBIK is valid (programmed) to the vehicle. The RF Hub communicates with the FOBIK using Frequency-Shift Keying (FSK) modulation.
Each antenna unit has two dedicated connections to the RF Hub. One connection is the LF antenna output circuit, while the other connection Is the LF antenna return circuit. These circuits to each antenna unit are a twisted pair to help reduce the potential for induced electrical interference. The Radio Frequency Hub Module (RFHM) microcontroller monitors all of the antenna units and will store a Diagnostic Trouble Code (DTC) for any fault that it detects.
The three switches of each Passive Entry (PE) outside door handle are powered by and provide a direct input to the Integrated Circuit (IC) of that door handle. The IC of each PE outside door handle receives power from the RFHM on a signal circuit, and a clean ground from the RFHM on a return circuit. The PE handle IC and the RFHM communicate with each other by modulating the current in the signal circuit.
Each PE outside door handle has three switches. The inputs from those three switches and the handle logic circuit allow each handle to send the RFHM up to four different signals: Unlock Request, Hall, Lock Request and Error. The RFHM determines the system response based upon the inputs it receives from each handle as well as the inputs it receives through the authentication process with each detected FOB with Integrated Key (FOBIK).
The tactile, mechanical, resistive membrane lock switch allows the user to actively lock the vehicle. The capacitive switch senses a hand approaching the handle pull to passively unlock the vehicle. The Hall-effect switch senses handle pull movement. An adaptation algorithm in the logic circuit of each handle can modify the sensitivity of the capacitive switches as well as system responses to the Hall-effect switch inputs to compensate for sensed repeated or continuous actuations such as might be caused by the switch membrane being wetted, but restores normal sensitivity about one minute after the repeated or continuous actuation input ceases.
The hard wired inputs and outputs of the antenna units may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, the most reliable, efficient, and accurate means to diagnose the antenna units requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

• Faulty Liftgate Handle Switch
• Liftgate Handle Switch harness is open or shorted
• Liftgate Handle Switch circuit poor electrical connection
• Faulty Radio Frequency Hub Module (RFHM)