GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2002 🢒 Impala 🢒 Body and Accessories 🢒 Lighting Systems 🢒 DTC B1482

Circuit Description

This DTC sets based upon the state of the inadvertent power relay control circuit in relation to the state expected by the BCM. The BCM controls the inadvertent power relay as part of the electrical power management system for this vehicle.

In order to minimize any battery rundown, the BCM can detect if certain electrical loads have been left on. When the BCM detects that the ignition is cycled to the OFF position, the BCM immediately checks the status of the courtesy lamp request circuit. If the BCM detects that a load is present, the BCM continues to keep the inadvertent power relay ON for 10 minutes by grounding the inadvertent power relay control circuit. If after 10 minutes the BCM still recognizes that a load is present, the BCM will turn OFF the inadvertent power relay, removing the battery voltage from the loads. The BCM continues to monitor the load monitor input circuit for a switch transition. The BCM will again turn the relay ON for 10 minutes after a switch transition.

Conditions for Running the DTC
    • Battery Rundown Protection / Inadvertent Power must be enabled.
    • The BCM must not be commanding the inadvertent power relay ACTIVE.

Conditions for Setting the DTC
    • The BCM is not commanding the inadvertent power relay ACTIVE.
    • The BCM detects a short to ground or open in the inadvertent power relay control circuit.
    • The above conditions last for more than 300 milliseconds.

Action Taken When the DTC Sets
    • The interior courtesy lamps do not operate.
    • The BCM stores DTC B1482 in memory.

Conditions for Clearing the DTC
    • A current DTC B1482 will clear if the short to ground or open in the inadvertent power relay control circuit is no longer detected by the BCM.
    • A history DTC B1482 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.

Test Description

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

  1. Listen for an audible click when the inadvertent power relay operates. Command both the ON and OFF states. Repeat the commands as necessary.

  2. Tests for voltage at the coil side of the inadvertent power relay. The DIC/RKE fuse supplies power to the coil side of the inadvertent power relay.

    3.

  3. Verifies that the Body Control Module (BCM) is providing ground to the inadvertent power relay.

    4.

  4. Tests if ground is constantly being applied to the inadvertent power relay.

Step

Action

Yes

No

Schematic Reference: Body Control System Schematics in Body Control System.

1

Did you perform the Diagnostic System Check for Engine Electrical?

Go to Step 2

Go to Diagnostic System Check - Engine Electrical

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, command the inadvertent power relay ON and OFF.

Does the inadvertent power relay turn ON and OFF with each command?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the inadvertent power relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the coil side feed circuit of the inadvertent power relay with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 4

Go to Step 10

4

  1. Connect a test lamp between the control circuit of the inadvertent power relay and the coil side feed circuit of the inadvertent power relay.
  2. With a scan tool, command the inadvertent power relay ON and OFF .

Does the test lamp turn ON and OFF with each command?

Go to Step 8

Go to Step 5

5

Does the test lamp remain illuminated with each command?

Go to Step 7

Go to Step 6

6

Test the control circuit of the inadvertent power relay for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 9

7

Test the control circuit of the inadvertent power relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 10

8

Inspect for poor connections at the inadvertent power relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 11

9

Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 12

10

Repair the coil side feed circuit of the inadvertent power relay. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 13

--

11

Replace the inadvertent power relay.

Did you complete the replacement?

Go to Step 13

--

12

Important: Perform the set up procedure for the Body Control Module. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 13

--

13
  1. Use the scan tool in order to clear the DTCs .
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK