GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The RFA system calibrations are stored in the EEPROM. When the ignition is first turned ON, the receiver performs internals tests on the EEPROM and can determine the integrity of the EEPROM's non-volatile memory. The receiver compares its previously stored checksum with the checksum calculated when the ignition is first turned ON. If the two checksums do not match, the receiver will indicate that a calibration malfunction (checksum error) is current.

Conditions for Setting the DTC

    • The stored checksum does not match the calculated checksum.
    • The receiver detects an internal memory malfunction (checksum error).
    • This condition must occur when the ignition is first turned ON.

Action Taken When the DTC Sets

    • Stores a DTC B0605 in the receiver memory
    • Sends a message to the IPC to display the SERVICE TIRE WARN SYS message
    • Disables all remote control functions

Conditions for Clearing the DTC

    • This DTC requires an ignition cycle in order to change from current to history.
    • The receiver no longer detects an internal memory malfunction condition (checksum error).
    • A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.
    • Use a scan tool.

Diagnostic Aids

Because the EEPROM is not removable from the receiver, and a DTC B0605 is an internal malfunction to the receiver, this malfunction is serviced only by receiver replacement. After replacement, the receiver must programmed to the vehicle's transmitters and the TPM sensors. Refer to Transmitter Programming/Synchronization and Tire Pressure Monitoring Sensor Programming in Tire Pressure Monitor.

Test Description

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

  1. Always perform the Remote Keyless Entry Diagnostic System Check before attempting to diagnose a DTC B0605.

  2. This repair procedure requires receiver replacement.

  3. Always clear the DTCs after the repair procedure is complete.

DTC B0605 -- Receiver Internal Memory Malfunction

Step

Action

Value(s)

Yes

No

1

Were you sent here from the Remote Keyless Entry Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Remote Keyless Entry

2

  1. Replace the remote control door lock receiver. Refer to Receiver Replacement .
  2. Program all TPM sensors. Refer to Tire Pressure Monitoring Sensor Programming in Tire Pressure Monitor.
  3. Program all RFA transmitters. Refer to Transmitter Programming/Synchronization .

Is the replacement complete?

--

Go to Step 3

--

3

  1. Turn the ignition to OFF.
  2. Install any components or connectors that were removed.
  3. Clear all DTCs. Refer to Clearing DTCs .

Are the repairs complete?

--

Go to Diagnostic System Check - Remote Keyless Entry

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