GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2000 🢒 Impala 🢒 Body and Accessories 🢒 Lighting Systems 🢒 DTC B2650 LH DRL Filament Open

Refer to

Headlamps Control


Object Number: 505936 Size: FS
Lighting Systems Components
Headlights/Daytime Running Lights (DRL) Circuit Description
Headlights and Power Distribution
Handling ESD Sensitive Parts Notice
Power, Grounds and RAP Relay
Headlights and Power Distribution
Headlights and Power Distribution
Headlights and Power Distribution
G201 (1 of 2)
LH HTD ST/BCM, DR LK, PWR MIR and CLSTR/BCM Fuses, HEADLAMP and RETAINED ACCSRY PWR Relays, and RETAINED ACCSRY PWR Circuit Breaker

Circuit Description

The Body Control Module (BCM) monitors the signal circuit of the high beam indicator control for high beam activity. When the high beam headlamps are commanded on by the DRL relay or the headlamp dimmer switch the high beam indicator control circuit is pulled to ground. B+ is applied to the DRL relay and the LH high beam headlamp from the DRL/EXT fuse and the RH high beam headlamp receives B+ from the EXT fuse.

Conditions for Running the DTC

The headlamps are not on and the DRL is not enabled.

Conditions for Setting the DTC
    • The BCM detects a short to ground or open in the signal circuit of the high beam indicator control. When the headlamps are off and the DRL are off.
    • The condition above must be present for more than 0.3 seconds.

Action Taken When the DTC Sets

The BCM stores DTC B2650 in memory.

Conditions for Clearing the DTC

DTC B2650 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.

Diagnostic Aids
    • If the DTC B2650 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections Intermittents and Poor Connections in wiring systems.
    • The following conditions may cause an intermittent malfunction to occur:
       - An intermittent short to ground in the signal circuit of the high beam indicator control.
       - An intermittent open in the signal circuit of the high beam indicator control.

Test Description

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

  1. Test the DRL relay for a stuck switch.

    2.

  2. Tests the headlamp dimmer switch for an internal short or bad switch.

Step

Action

Yes

No

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems in Lighting Systems.

2
  1. Install a scan tool.
  2. Set the parking brake.
  3. Place a bright light over the ambient light sensor.
  4. Turn the headlamp switch to the OFF position.
  5. Turn ON the ignition, with the engine OFF.
  6. With a scan tool, observe the Hi beam On switch parameter in the body control module data list.

Does the scan tool display active?

Go to Diagnostic Aids

Go to Step 3

3
  1. Remove the LH high beam headlamp.
  2. Using a test lamp connected to a known good ground, probe the high beam indicator control circuit at the LH high beam headlamp harness connector.

Does the test lamp illuminate?

Go to Step 5

Go to Step 4

4

  1. Disconnect the RH headlamp assembly.
  2. Using a test lamp connected to a known good ground, probe the high beam indicator control circuit at the LH headlamp harness connector.

Does the test lamp illuminate?

Go to Step 9

Go to Step 13

5

  1. Using a test lamp probe between the high beam indicator control circuit and the switched ground circuit of the DRL relay at the LH headlamp harness connector.
  2. Using a scan tool, command the DRL relay on.

Does the test lamp illuminate?

Go to Step 15

Go to Step 6

6
  1. Disconnect the headlamp assembly.
  2. Using a test lamp probe between the high beam indicator control circuit and the switched ground circuit of the DRL relay at the LH headlamp harness connector.
  3. Using a scan tool, command the DRL relay on.

Does the test lamp illuminate?

Go to Step 9

Go to Step 10

7
  1. Remove the DRL relay.
  2. Using a test lamp probe between B+ and the ground circuit of the DRL relay.

Does the test lamp illuminate?

Go to Step 8

Go to Step 12

8
  1. Install a fused 3A jumper in the DRL relay connector between the ground circuit and the DRL relay switched ground circuit.
  2. At the LH headlamp assembly, connect a test lamp between B+ and the LH high beam headlamp switched ground circuit.

Does the test lamp illuminate?

Go to Step 10

Go to Step 11

9

Inspect for a poor connection at the harness connectors of the LH high beam headlamp. Refer to Testing for Intermittent Conditions and Poor Connections Testing for Intermittent and Poor Connections and Connector Repairs Connector Repairs in wiring systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 16

10

Inspect for a poor connection at the DRL Relay. Refer to Testing for Intermittent Conditions and Poor Connections Testing for Intermittent and Poor Connections and Connector Repairs Connector Repairs in wiring systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 14

11

Repair a poor connection or an open in the DRL switched ground circuit.

Refer to Circuit Testing Circuit Testing in Wiring Systems and Wiring Repairs Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 17

--

12

Repair a poor connection or an open in the ground circuit of the DRL Relay.

Refer to Circuit Testing Circuit Testing in Wiring Systems and Wiring Repairs Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 17

--

13

Repair a poor connection or an open in the high beam indicator control circuit.

Refer to Circuit Testing Circuit Testing in Wiring Systems and Wiring Repairs Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 17

--

14

Replace the DRL relay.

Did you complete the repair?

Go to Step 17

--

15

Replace the LH high beam headlamp bulb.

Did you complete the repair?

Go to Step 17

--

16

Replace the LH headlamp assembly. Refer to Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement .

Did you complete the repair?

Go to Step 17

--

17
  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