Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 2: Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
- 3: The Lighting Systems Symptoms will determine the correct diagnostic procedure to use when no DTCs are present.
- 4: The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.
- 5: DTC B1000 and DTC B1001 are internal BCM malfunctions and should be corrected before performing any other diagnostic procedure.
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | Install a scan tool. Does the scan tool power up? | Go to Step 2 | Go to Scan Tool Does Not Power Up in Data Link Communications |
| 2 | Turn ON the ignition, with the engine OFF. Attempt to establish communication with the body control module (BCM). Does the scan tool communicate with the BCM? | Go to Step 3 | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications |
| 3 | Select the BCM display DTCs function on the scan tool. Does the scan tool display any DTCs? | Go to Step 4 | Go to Symptoms - Lighting Systems |
| 4 | Does the scan tool display any DTCs which begin with a "U"? | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | Go to Step 5 |
| 5 | Does the scan tool display DTC B1000 or B1001? | Go to Diagnostic Trouble Code (DTC) List in Body Control System | Go to Diagnostic Trouble Code (DTC) List |
Diagnostic System Check - Lighting Systems
The numbers below refer to the step numbers on the diagnostic table.
- 2: Listen for an audible click when the fog lamp relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
- 3: Tests for voltage at the coil side of the fog lamp relay.
- 4: Verifies that the body control module is providing ground to the fog lamp relay.
- 5: Tests if ground is constantly being applied to the fog lamp relay.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Fog Lights Schematics | |||
| 1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the fog lamp relay ON and OFF. Does the fog lamp relay state change with each command? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
| 3 | Turn OFF the ignition. Disconnect the fog lamp relay. Place the headlamp switch in the PARK position. Probe the coil side battery positive voltage circuit of the fog lamp 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 | Connect a test lamp between the control circuit of the fog lamp relay and the coil side battery positive voltage circuit of the fog lamp relay. With a scan tool, command the fog lamp 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 fog lamp relay for a high resistance or 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 fog lamp 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 9 |
| 8 | Inspect for poor connections at the fog lamp 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. 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 open in the coil side battery positive voltage circuit of the fog lamp relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 13 | |
| 11 | Replace the fog lamp relay. Did you complete the replacement? | Go to Step 13 | |
| 12 | IMPORTANT: Perform the set up procedure for the body control module. Replace the body control module. Refer to Body Control Module Replacement in Body Control Systems.Did you complete the replacement? | Go to Step 13 | |
| 13 | Use the scan tool in order to clear the DTCs. 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 |
| IMPORTANT |
|---|
| Perform the set up procedure for the body control module. |
DTC B2532 Circuit
The numbers below refer to the step numbers on the diagnostic table.
- 2: Listen for an audible click when the fog lamp relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
- 3: Tests for voltage at the coil side of the fog lamp relay.
- 4: Verifies that the body control module is providing ground to the fog lamp relay.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Fog Lights Schematics | |||
| 1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the fog lamp relay ON and OFF. Does the fog lamp relay state change with each command? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
| 3 | Turn OFF the ignition. Disconnect the fog lamp relay. Turn ON the ignition, with the engine OFF. Turn the headlamp switch to the PARK or HEAD position. Probe the coil side battery positive voltage circuit between the fog lamp relay and the headlamp switch with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 4 | Go to Step 8 |
| 4 | Connect a test lamp between the control circuit of the fog lamp relay and the coil side battery positive voltage circuit of the fog lamp relay. Place the headlamp switch in the PARK or HEADLAMP position. With a scan tool, command the fog lamp relay ON and OFF. Does the test lamp turn ON and OFF with each command? | Go to Step 6 | Go to Step 5 |
| 5 | Test the control circuit of the fog lamp relay for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 7 |
| 6 | Inspect for poor connections at the fog lamp 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 11 | Go to Step 9 |
| 7 | Inspect for poor connections at the harness connector of the body control module. 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 11 | Go to Step 10 |
| 8 | Repair the open in the coil side battery positive voltage circuit of the fog lamp relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 11 | |
| 9 | Replace the fog lamp relay. Did you complete the replacement? | Go to Step 11 | |
| 10 | IMPORTANT: Perform the set up procedure for the body control module. Replace the body control module. Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement? | Go to Step 11 | |
| 11 | Use the scan tool in order to clear the DTCs. 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 |
| IMPORTANT |
|---|
| Perform the set up procedure for the body control module. |
DTC B2533 Circuit
Scheme 12
The numbers below refer to the step numbers on the diagnostic table.
- 2: Listen for an audible click when the headlamp relay operates. Command both the ON and OFF states. Repeat the commands, as necessary.
- 3: Tests for voltage at the coil side of the headlamp relay. The BACKUP/TURN fuse supplies battery positive voltage to the coil side of the headlamp relay.
- 4: Verifies that the BCM is providing ground to the headlamp relay.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics (w/ T82) Headlights/Daytime Running Lights (DRL) Schematics (w/o T82) | |||
| 1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the headlamp relay ON and OFF. Does the headlamp 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 | Turn OFF the ignition. Disconnect the headlamp relay. Turn ON the ignition, with the engine OFF. Probe the coil side battery positive voltage circuit of the headlamp relay with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 4 | Go to Step 8 |
| 4 | Connect a test lamp between the control circuit of the headlamp relay and the coil side battery positive voltage circuit of the headlamp relay. With a scan tool, command the headlamp relay ON and OFF. Does the test lamp turn ON and OFF with each command? | Go to Step 6 | Go to Step 5 |
| 5 | Test the control circuit of the headlamp relay for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 7 |
| 6 | Inspect for poor connections at the headlamp 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 11 | Go to Step 9 |
| 7 | Inspect for poor connections at the harness connector of the body control module. 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 11 | Go to Step 10 |
| 8 | Repair the open in the coil side battery positive voltage circuit of the headlamp relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 11 | |
| 9 | Replace the headlamp relay. Refer to Relay Replacement (Within an Electrical Center) Relay Replacement (Attached to Wire Harness) in Wiring Systems. Did you complete the replacement? | Go to Step 11 | |
| 10 | IMPORTANT: Perform the set up procedure for the body control module. Replace the body control module. Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement? | Go to Step 11 | |
| 11 | Use the scan tool in order to clear the DTCs. 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 |
| IMPORTANT |
|---|
| Perform the set up procedure for the body control module. |
DTC B2575 Circuit
The numbers below refer to the step numbers on the diagnostic table.
- 2: Listen for an audible click when the headlamp relay operates. Command both the ON and OFF states. Repeat the commands, as necessary.
- 3: Tests for voltage at the coil side of the headlamp relay. The BACKUP/TURN fuse supplies battery positive voltage to the coil side of the headlamp relay.
- 4: Verifies that the BCM is providing ground to the headlamp relay.
- 5: Tests if ground is constantly being applied to the headlamp relay.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics (w/ T82) Headlights/Daytime Running Lights (DRL) Schematics (w/o T82) | |||
| 1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the headlamp relay ON and OFF. Does the headlamp 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 | Turn OFF the ignition. Disconnect the headlamp relay. Turn ON the ignition, with the engine OFF. Probe the coil side battery positive voltage circuit of the headlamp 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 | Connect a test lamp between the control circuit of the headlamp relay and the coil side battery positive voltage circuit of the headlamp relay. With a scan tool, command the headlamp 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 headlamp relay for a high resistance or 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 headlamp 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 9 |
| 8 | Inspect for poor connections at the headlamp 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 battery positive voltage circuit of the headlamp relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 13 | |
| 11 | Replace the headlamp relay. Refer to Relay Replacement (Within an Electrical Center) Relay Replacement (Attached to Wire Harness) in Wiring Systems. Did you complete the replacement? | Go to Step 13 | |
| 12 | IMPORTANT: Perform the set up procedure for the BCM. Replace the BCM. Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement? | Go to Step 13 | |
| 13 | Use the scan tool in order to clear the DTCs. 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 |
| IMPORTANT |
|---|
| Perform the set up procedure for the BCM. |
DTC B2577 Circuit
The number below refers to the step number on the diagnostic table.
- 2: Listen for an audible click when the headlamp relay operates. Command both the ON and OFF states. Repeat the commands, as necessary.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics (w/ T82) Headlights/Daytime Running Lights (DRL) Schematics (w/o T82) | |||
| 1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the headlamp relay ON and OFF. Does the headlamp 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 | Test for a short to voltage in the control circuit of the headlamp relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 6 | Go to Step 4 |
| 4 | 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 6 | Go to Step 5 |
| 5 | IMPORTANT: Perform the set up procedure for the BCM. Replace the BCM. Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement? | Go to Step 6 | |
| 6 | Use the scan tool in order to clear the DTCs. 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 |
| IMPORTANT |
|---|
| Perform the set up procedure for the BCM. |
DTC B2578 Circuit
Scheme 13
The numbers below refer to the step numbers on the diagnostic table.
- 2: Listen for an audible click when the park lamp relay operates. Command both the ON and OFF states. Repeat the commands, as necessary.
- 3: Tests for voltage at the coil side of the park lamp relay. The PARK LAMP fuse supplies battery positive voltage to the coil side of the park lamp relay.
- 4: Verifies that the BCM is providing ground to the park lamp relay.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Exterior Lights Schematics | |||
| 1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the park lamps ON and OFF. Does the park ramp 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 | Turn OFF the ignition. Disconnect the park lamp relay. Turn ON the ignition, with the engine OFF. Probe the coil side battery positive voltage circuit of the park lamp relay with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 4 | Go to Step 9 |
| 4 | Connect a test lamp between the control circuit of the park lamp relay and the coil side battery positive voltage circuit of the park lamp relay. With a scan tool, command the park lamp relay ON and OFF. Does the test lamp turn ON and OFF with each command? | Go to Step 5 | Go to Step 6 |
| 5 | Test for an open or high resistance in the park lamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 7 |
| 6 | Test for an open, high resistance, or short to voltage in the control circuit of the park lamp relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 8 |
| 7 | Inspect for poor connection at the park lamp 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 12 | Go to Step 10 |
| 8 | 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 12 | Go to Step 11 |
| 9 | Repair an open, high resistance, or short to ground in the coil side battery positive voltage circuit of the park lamp relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 12 | |
| 10 | Replace the park lamp relay. Refer to Relay Replacement (Within an Electrical Center) Relay Replacement (Attached to Wire Harness) in Wiring Systems. Did you complete the replacement? | Go to Step 12 | |
| 11 | IMPORTANT: Perform the set up procedure for the body control module. Replace the body control module. Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement? | Go to Step 12 | |
| 12 | Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset? | Go to Step 2 | |
| IMPORTANT |
|---|
| Perform the set up procedure for the body control module. |
DTC B2585 Circuit
The numbers below refer to the step numbers on the diagnostic table.
- 2: Listen for an audible click when the park lamp relay operates. Command both the ON and OFF states. Repeat the commands, as necessary.
- 3: Tests for voltage at the coil side of the park lamp relay. The PARK LAMP fuse supplies battery positive voltage to the coil side of the park lamp relay.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Exterior Lights Schematics | |||
| 1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the park lamps ON and OFF. Does the park lamp 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 | Turn OFF the ignition. Disconnect the park lamp relay. Turn ON the ignition, with the engine OFF. Probe the coil side battery positive voltage circuit of the park lamp 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 | Connect a test lamp between the coil side battery positive voltage circuit of the park lamp relay and the control circuit of the park lamp relay. With a scan tool, command the park lamps ON and OFF. Does the test lamp turn on and off? | Go to Step 8 | Go to Step 5 |
| 5 | Is the test lamp illuminated? | Go to Step 6 | Go to Step 7 |
| 6 | Test for a short to ground in the control circuit of the park lamp relay. 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 for an open or high resistance in the control circuit of the park lamp relay. 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 |
| 8 | Inspect for poor connections at the park lamp 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 an open, high resistance, or short to ground in the coil side battery positive voltage circuit of the park lamp relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 13 | |
| 11 | Replace the park lamp relay. Refer to Relay Replacement (Within an Electrical Center) Relay Replacement (Attached to Wire Harness) in Wiring Systems. Did you complete the replacement? | Go to Step 13 | |
| 12 | IMPORTANT: Perform the set up procedure for the BCM. Replace the BCM. Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement? | Go to Step 13 | |
| 13 | Use the scan tool in order to clear the DTCs. 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 |
| IMPORTANT |
|---|
| Perform the set up procedure for the BCM. |
DTC B2587 Circuit
The number below refers to the step number on the diagnostic table.
- 2: Listen for an audible click when the park lamp relay operates. Command both the ON and OFF states. Repeat the commands, as necessary.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Exterior Lights Schematics | |||
| 1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the park lamps ON and OFF. Does the park lamp 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 | Test the control circuit of the park lamp relay for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 6 | Go to Step 4 |
| 4 | 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 6 | Go to Step 5 |
| 5 | IMPORTANT: Perform the set up procedure for the BCM. Replace the BCM. Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement? | Go to Step 6 | |
| 6 | Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset? | Go to Step 2 | |
| IMPORTANT |
|---|
| Perform the set up procedure for the BCM. |
DTC B2588 Circuit
Scheme 14
The numbers below refer to the step numbers on the diagnostic table.
- 2: Listen for an audible click when the DRL relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
- 3: Tests for voltage at the coil side of the DRL relay.
- 4: Verifies that the body control module is providing ground to the DRL relay.
- 5: Tests if ground is constantly being applied to the DRL relay.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics (w/ T82) Headlights/Daytime Running Lights (DRL) Schematics (w/o T82) | |||
| 1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the DRL relay ON and OFF. Does the DRL 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 | Turn OFF the ignition. Disconnect the DRL relay. Turn ON the ignition, with the engine OFF. Probe the coil side battery positive voltage circuit of the DRL 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 | Connect a test lamp between the control circuit of the DRL relay and the coil side battery positive voltage circuit of the DRL relay. With a scan tool, command the DRL 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 DRL 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 DRL 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 9 |
| 8 | Inspect for poor connections at the DRL 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. 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 an open, high resistance, or short to ground in the coil side battery positive voltage circuit of the DRL relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 13 | |
| 11 | Replace the DRL relay. Did you complete the replacement? | Go to Step 13 | |
| 12 | IMPORTANT: Perform the set up procedure for the body control module. Replace the body control module. Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement? | Go to Step 13 | |
| 13 | Use the scan tool in order to clear the DTCs. 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 |
| IMPORTANT |
|---|
| Perform the set up procedure for the body control module. |
DTC B2602 Circuit
The numbers below refer to the step numbers on the diagnostic table.
- 2: The normal operating voltage of the instrument panel dimmer switch is 0.4-4.5 volts.
- 3: This step determines if there is a problem with the dimmer switch.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Interior Lights Dimming Schematics | ||||
| 1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems | |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, observe the I/P Dimmer Input data parameter in the Interior Lamps data list. Does the scan tool indicate that the I/P Dimmer Input parameter is within the specified range? | 0.4-4.5 volts | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
| 3 | Turn OFF the ignition. Disconnect the instrument panel dimmer switch. Turn ON the ignition, with the engine OFF. With a scan tool, observe the I/P Dimmer Input data parameter. Does the scan tool indicate that the I/P Dimmer Input data parameter is greater than the specified value? | 4.5 volts | Go to Step 5 | Go to Step 4 |
| 4 | Test the 5 volt reference circuit and the instrument panel lamps dimmer switch signal circuit for an open, high resistance, or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 6 | |
| 5 | Inspect for poor connections at the harness connector of the instrument panel dimmer switch. 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 9 | Go to Step 7 | |
| 6 | Inspect for poor connections at the harness connector of the body control module. 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 9 | Go to Step 8 | |
| 7 | Replace the instrument panel dimmer switch. Did you complete the replacement? | Go to Step 9 | Go to Step 9 | |
| 8 | 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 body control module. Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement? | Go to Step 9 | ||
| 9 | Use the scan tool in order to clear the DTCs. 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 | |
| IMPORTANT |
|---|
| Perform the set up procedure for the body control module. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System. |
DTC B2622 Circuit
The numbers below refer to the step numbers on the diagnostic table.
- 2: The normal operating voltage of the instrument panel dimmer switch is 0.4-4.5 volts.
- 3: This step determines if there is a problem with the dimmer switch.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Interior Lights Dimming Schematics | ||||
| 1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems | |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, observe the I/P Dimmer Input Data parameter in the Interior Lamps data list. Does the scan tool indicate that the I/P Dimmer Input parameter is greater than the specified range? | 4.5 Volts | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems |
| 3 | Turn OFF the ignition. Disconnect the instrument panel dimmer switch. Turn ON the ignition, with the engine OFF. With a scan tool, observe the I/P Dimmer Input Data parameter. Does the scan tool indicate that the I/P Dimmer Input Data parameter is greater than the specified value? | 4.5 Volts | Go to Step 4 | Go to Step 5 |
| 4 | Test the 5-volt reference circuit and the instrument panel lamps dimmer switch signal circuit for an open or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 6 | |
| 5 | Inspect for poor connections at the harness connector of the instrument panel dimmer switch. 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 9 | Go to Step 7 | |
| 6 | Inspect for poor connections at the harness connector of the body control module. 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 9 | Go to Step 8 | |
| 7 | Replace the instrument panel dimmer switch. Did you complete the replacement? | Go to Step 9 | Go to Step 9 | |
| 8 | 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 body control module. Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement? | Go to Step 9 | ||
| 9 | Use the scan tool in order to clear the DTCs. 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 | |
| IMPORTANT |
|---|
| Perform the set up procedure for the body control module. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System. |
DTC B2623 Circuit
The numbers below refer to the step numbers on the diagnostic table.
- 2: The normal operating voltage of the ambient light sensor (photocell) is 0.5-4.5 volts.
- 3: This step determines if there is a problem with the signal circuit of the ambient light sensor.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics (w/ T82) Headlights/Daytime Running Lights (DRL) Schematics (w/o T82) | ||||
| 1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems | |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, observe the PHOTOCELL VOLTAGE data parameter in the LAMP STATUS data list. Does the scan tool indicate that the PHOTOCELL VOLTAGE parameter is within the specified range? | 0.5-4.5 Volts | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
| 3 | Turn OFF the ignition. Disconnect the ambient light sensor. Turn ON the ignition, with the engine OFF. Probe the signal circuit of the ambient light sensor with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 4 | Go to Step 5 | |
| 4 | Connect a fused jumper wire between the signal circuit of the ambient light sensor and the low reference circuit of the ambient light sensor. With a scan tool, observe the PHOTOCELL VOLTAGE data parameter in the LAMP STATUS data list. Does the scan tool indicate that the PHOTOCELL VOLTAGE parameter is within the specified range? | 4.5-5.0 Volts | Go to Step 7 | Go to Step 6 |
| 5 | Test the signal circuit of the ambient light sensor for an open, high resistance, or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 8 | |
| 6 | Test the low reference circuit of the ambient light sensor for an open, high resistance, or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 8 | |
| 7 | Inspect for poor connections at the harness connector of the ambient light sensor. 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 11 | Go to Step 9 | |
| 8 | 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 11 | Go to Step 10 | |
| 9 | Replace the ambient light sensor. Did you complete the replacement? | Go to Step 11 | ||
| 10 | IMPORTANT: Perform the set up procedure for the BCM. Replace the BCM. Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement? | Go to Step 11 | ||
| 11 | Use the scan tool in order to clear the DTCs. 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 | |
| IMPORTANT |
|---|
| Perform the set up procedure for the BCM. |
DTC B2647 Circuit
