The LOW battery detection is handled inside the transmitter. The transmitter sends a battery condition signal to the remote control door lock receiver (RCDLR) when the transmitter buttons are pressed.
This diagnostic procedure supports the following DTC:
DTC B3109 Keyless Entry Transmitter (Single or 1) Low Battery
This code shall be set after 3 consecutive low battery signals from the same programmed transmitter.
This code is cleared as current when a normal transmitter voltage signal is received from any programmed transmitter.
The numbers below refer to the step numbers on the diagnostic table.
This step identifies the key fob # (transmitter) with a low battery signal.
This step verifies that the battery replacement corrected the fault.
Step  | Action  | Yes  | No  | 
|---|---|---|---|
Schematic Reference: Keyless Entry Schematics Connector End View Reference: Keyless Entry Connector End Views  | |||
1  | Did you perform the Diagnostic System Check - Vehicle?  | Go to Step 2  | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information  | 
2  | 
 Does the scan tool indicate that DTC B3109 is current?  | Go to Step 3  | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems  | 
 Did you complete the batteries replacement?  | Go to Step 4  | --  | |
 Does the DTC reset?  | Go to Step 5  | System OK  | |
5  | Inspect for poor connections at the battery connections of the transmitters that set the DTC. Did you find and correct the condition?  | System OK  | Go to Step 6  | 
6  | 
 Did you complete the replacement?  | Go to Step 7  | --  | 
7  | 
 Does the DTC reset?  | Go to Step 8  | System OK  | 
8  | Replace the remote control door lock receiver (RCDLR). Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement?  | System OK  | --  |