GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The low battery detection is handled inside the transmitter. The transmitter sends a battery condition signal to the body control module (BCM) when the transmitter buttons are pressed.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B3109 RFA Key Fob Battery Low

DTC Symptom

DTC Symptom Descriptor

00

No Additional Information

Conditions for Running the DTC

The RFA system must be enabled.

Conditions for Setting the DTC

This code shall be set after 3 consecutive low battery signals from the same programmed transmitter.

Conditions for Clearing the DTC

This code is cleared as current when a normal transmitter voltage signal is received from any programmed transmitter.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step performs the Diagnostic System Check.

  2. This step checks DTC status as current or history in Remote Function Actuation Menu on the scan tool.

  3. This step identifies the key fob # , transmitter, with a low battery signal.

  4. This step verifies that the battery replacement corrected the fault.

Step

Action

Yes

No

Schematic Reference: Keyless Entry Schematics

Connector End Views: Keyless Entry Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Select Body and Accessories.
  4. Select Keyless Entry.
  5. Select Diagnostic Trouble Codes.

Does the scan tool display DTC B3109 as a current DTC?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3

  1. With a scan tool, observe the Key Fob Low Voltage parameters for each transmitter in the Door Lock Information data list to identify the programmed transmitter that set the code.
  2. Replace the batteries on the indicated transmitters. Refer to Transmitter Battery Replacement .

Did you complete the battery replacement?

Go to Step 4

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4

  1. Use the scan tool in order to clear DTCs.
  2. Operate for 3 consecutive times the transmitters that had the battery replaced.

Does the DTC reset?

Go to Step 5

System OK

5

Inspect for poor connections at the battery connection of the transmitters that set the DTC.

Did you find and correct the condition?

System OK

Go to Step 6

6

  1. Replace the transmitter.
  2. Ensure that the replacement transmitter is the correct model for the vehicle.
  3. All transmitters must be programmed at the same time. Refer to Transmitter Programming .

Did you complete the replacement?

Go to Step 7

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7

  1. Use scan tool in order to clear the DTCs.
  2. Operate the replacement transmitters 3 consecutive times.

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

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