GM Service Manual Online
For 1990-2009 cars only

Circuit Description

Battery power is supplied to the integrated radio controller (IRC) by the battery guard relay on circuit A52.. The body control module (BCM) controls the output to the battery guard relay. The IRC monitors the voltage to determine if it is within a valid operating range.

Conditions for Setting the DTC

DTC B1982 will set when the source voltage to the IRC exceeds15.5 volts for 1.2 seconds.

Action Taken When the DTC Sets

    • DTC B1982 will be stored in the IRC memory.
    • A current DTC B1982 prevents the IRC from setting a Class 2 Loss of Serial Data, short to ground or battery DTC.
    • The IRC will not respond to any manual or memory inputs when the voltage is greater than 15.5 volts.
    • No driver warning message will be displayed for this DTC.

Conditions for Clearing the DTC

    • DTC B1982 will clear when the source voltage is below 15.5 volts for 1.2 seconds.
    • DTC B1982 can also be cleared by using the scan tool.

Diagnostic Aids

DTC B1982 may set if the vehicle is placed on a battery charger, on fast charge, for a long period of time.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. Clear all DTCs and cycle the ignition to check that the DTC did not falsely set.

  2. This step tests the charging system for an overcharge condition.

Step

Action

Value(s)

Yes

No

1

Was the Radio/Audio System Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Radio/Audio System

2

  1. Install the scan tool.
  2. Turn the ignition switch to the ON position.
  3. Clear any DTCs.
  4. Turn the ignition OFF.
  5. Start the engine.
  6. Retest for a DTC B1982.

Is the DTC still present?

--

Go to Step 3

System OK

3

Measure the voltage at the battery with the engine running.

Is the measured voltage above the specified value?

15.5 V

Go to Step 4

Go to Step 5

4

Repair the charging system. Refer to the Charging System Check in Engine Electrical.

Is the repair complete?

--

Go to Step 6

--

5

Replace the radio. Refer to Radio Replacement .

Is the replacement complete?

--

Go to Step 6

--

6

  1. Install the scan tool in order to clear codes.
  2. Verify that DTC B1982 is not present.

Are all DTCs cleared?

--

System OK

--