GM Service Manual Online
For 1990-2009 cars only

Object Number: 259750  Size: MF
Radio/Audio System Circuit Description
Cell 150: Power and Ground
Cell 150: Amplifier - Power, Ground
Handling ESD Sensitive Parts Notice
Power Distribution Schematics
Ground Distribution Schematics

Circuit Description

The radio amplifier contains a data storage area which can save pertinent data when the ignition is turned off. The keep alive memory (KAM) data is lost if battery power is removed from the radio amplifier.

Conditions for Setting the DTC

DTC B1004 indicates that the keep alive, or long-term, memory in the radio amplifier has been reset. It is a normal occurrence whenever power or ground is removed from the radio amplifier.

Action Taken When the DTC Sets

Module KAM memory resets to initial values.

Conditions for Clearing the DTC

    • This DTC requires an ignition cycle in order to change from current to history.
    • The DTC clears if the radio amplifier no longer detects a KAM failure (checksum error).
    • A history DTC clears after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.

Diagnostic Aids

This DTC may set if the vehicle battery has been disconnected or if a low battery charge condition has occurred.

Test Description

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

  1. Perform the Radio/Audio Diagnostic System Check before continuing with the diagnosis of this DTC.

  2. Clear all DTCs and cycles ignition to check that the DTC did not falsely set.

  3. Clear all DTCs after the repair procedure is complete.

DTC B1004 -- Loss of Keep Alive Memory

Step

Action

Value(s)

Yes

No

1

Was the Radio/Audio Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Radio/Audio System

2

  1. Turn the ignition switch to ON.
  2. Clear all DTCs. Refer to Clearing DTCs .
  3. Turn the ignition switch to OFF.
  4. Turn the ignition switch to ON.

Is the DTC still present?

--

Go to Step 3

Go to Diagnostic System Check - Radio/Audio System

3

Replace the radio amplifier. Refer to Radio Speaker Amplifier Replacement .

Is the replacement complete?

--

Go to Step 4

--

4

  1. Turn the ignition switch to OFF.
  2. Reconnect or install any connectors or components that were disconnected or removed.
  3. Turn the ignition switch to ON.
  4. Clear any DTCs. Refer to Clearing DTCs .

Are all DTCs cleared?

--

Go to Diagnostic System Check - Radio/Audio System

--