GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 1998 🢒 Intrigue 🢒 Body and Accessories 🢒 Body Control System 🢒 DTC B2805 RFA Programming Message Not Received

Object Number: 308606 Size: SF
Handling Electrostatic Discharge Sensitive Parts Notice
Handling Electrostatic Discharge Sensitive Parts Notice
Body Control Module Components
Body Control System Schematics

Circuit Description

The keyless entry system allows the driver to do the following functions from outside the vehicle by using a hand held radio transmitter:

    • Unlock the door locks. The courtesy lights activate automatically when using this function.
    • Lock the door locks.
    • Release the rear compartment lid.
    • Remote alarm.

The transmitter operates in the UHF band. The transmitter sends digitally coded signals to the Remote Control Door Lock Receiver (RCDLR) when pressing any of the transmitter buttons.

The RCDLR detects and decodes transmitter signals. For locking, unlocking, and remote alarm commands, the RCDLR sends command messages to the Body Control Module (BCM) to operate the door locks actuators, courtesy lights, and remote alarm.

The BCM has the ability to enable the transmitter programming/diagnostic mode. The BCM monitors messages on the RFA link to prevent message collisions. The BCM also receives programming signals from the RCDLR when attempting to enable transmitter programming/diagnostic mode.

Conditions for Setting the DTC
  1. The BCM receives the programming signals from the RCDLR when attempting to enable the transmitter programming/diagnostic mode.
  2. The BCM expects to receive a program signal from the RCDLR and it does not after two tries.

Action Taken When the DTC Sets
    • The BCM stores DTC B2805 in memory.
    • The RCDLR does not enter transmitter programming/diagnostic mode.

Conditions for Clearing the DTC
    • Under all fault conditions, the ignition switch must be cycled form off to on before this DTC can change from current to history.
    • A history DTC will clear after 100 consecutive ignition cycles if the condition for the fault is no longer present.
    • Using a scan tool.

Diagnostic Aids
    • The following conditions may cause an intermittent malfunction to occur:
      • An intermittent open in circuit 917.
      • Poor connections at the BCM or the RCDLR.
      • The BCM is open internally.
      • The RCDLR is open internally.
    • The BCM checks for DTC B2805 only when attempting to enable transmitter programming/diagnostic mode. Refer to Transmitter Programming in Keyless Entry for more information on how to enter this mode.
    • DTC P1626 will set in the Powertrain Control Module (PCM) when the ignition switch is on with the Body Control Module (BCM) disconnected. When BCM diagnostics and repairs are completed, refer to Powertrain Control Module Diagnosis in Engine Controls for additional information on PCM related DTCs.

Test Description

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

  1. This step checks for communication between the BCM and the RCDLR when entering the transmitter programming/diagnostic mode.

    2.

  2. This step checks if DTC B2805 resets when entering the transmitter programming/diagnostic mode.

    3.

  3. This step checks for communication between the BCM and the RCDLR when using the keyless entry transmitter.

    4.

  4. This step determines whether the RCDLR or the BCM is faulty.

Step

Action

Value(s)

Yes

No

1

Was the BCM diagnostic system check performed?

--

Go to Step 2

Go to Diagnostic System Check - Body Control System

2

  1. Turn the ignition switch off.
  2. Attempt to enable the transmitter programming/diagnostic mode. Refer to Transmitter Programming in Keyless Entry for procedure.

Were you able to enter the transmitter programming/diagnostic mode?

--

Go to Step 3

Go to Step 4

3

  1. Exit the transmitter programming/diagnostic mode by turning the ignition switch on.
  2. Clear BCM DTCs. Refer to Clearing DTCs for more information.
  3. Turn the ignition switch off.
  4. Enable the transmitter programming/diagnostic mode again. Refer to Transmitter Programming in Keyless Entry for procedure.
  5. Check for BCM DTCs. Refer to Diagnostic Trouble Code (DTC) Displaying for more information.

Does DTC B2805 reset as a current DTC?

--

Go to Step 6

Go to Step 8

4

  1. Remove key from the ignition switch.
  2. While observing the door locks, press lock using the keyless entry transmitter.
  3. While observing the door locks, press unlock using the keyless entry transmitter.

Did the door locks lock and unlock by using the keyless entry transmitter?

--

Go to Step 9

Go to Step 5

5

  1. Using the Device Control function on a Tech 2 scan tool, activate the RFA link output.
  2. Using a DMM, measure the voltage by backprobing between the BCM harness connector C1 terminal C15 and ground.

Is the voltage within the specified range when the RFA link was active?

Less than 2V

Go to Step 7

Go to Step 6

6
  1. Replace the BCM. Refer to Body Control Module Replacement for more information.
  2. After replacing the BCM, perform the Setup New BCM procedure. Refer to Body Control Module (BCM) Programming/RPO Configuration for more information.

Is the repair complete?

--

Go to Step 9

--

7
    • Check the RCDLR connector for poor terminal contact.
    • If the connector is OK, then replace the RCDLR. Refer to Receiver Replacement in Keyless Entry for service procedure.

Is the repair complete?

--

Go to Step 9

--

8

The malfunction is not present at this time. Refer to Diagnostic Aids for additional information regarding this DTC.

--

--

9
  1. Turn the ignition switch off.
  2. Reinstall connectors/components removed.
  3. Turn the ignition switch on.
  4. Clear BCM DTCs. Refer to Clearing DTCs for more information.
  5. Check for BCM current DTCs. Refer to Diagnostic Trouble Code (DTC) Displaying for more information.

Are there any BCM current DTCs set?

--

Go to Diagnostic System Check - Body Control System

System OK