Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 2: This step test determines if an open or short to ground exists.
- 3: This step test determines if a short to ground exists in the lamp wiring or internally within the BCM.
- 4: This step test determines if an open exists in the body wiring harness extension harness or internally within the BCM.
- 8: After replacement of the BCM you must calibrate the new module for proper operation.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Interior Lights Schematics Connector End View Reference: Lighting Systems Connector End Views or Data Communication Connector End Views | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Inspect the truck body controller (TBC) 4 fuse in the rear fuse block. Is the fuse good? | Go to Step 4 | Go to Step 3 |
| 3 | Test the inadvertent power courtesy lamps supply voltage circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 9 | Go to Step 5 |
| 4 | Test the TBC 4 battery positive supply voltage circuit at the body wiring harness extension harness connector at the body control module (BCM) for battery voltage. Refer to Circuit Testing . Is battery voltage present? | Go to Step 5 | Go to Step 6 |
| 5 | Inspect for poor connections at the harness connectors of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 9 | Go to Step 8 |
| 6 | Inspect for poor connections at the body wiring harness extension harness connectors. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 9 | Go to Step 7 |
| 7 | Replace the body wiring harness extension harness to the BCM. Refer to Body Wiring Harness Extension Replacement - BCM for replacement, setup, and programming. Did you complete the replacement? | Go to Step 9 | |
| 8 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. 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 |
DTC B1480
The numbers below refer to the step numbers on the diagnostic table.
- 2: Listen for an audible click when the front fog lamp relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
- 3: This step tests for voltage at the coil side of the front fog lamp relay.
- 4: This step verifies that the BCM is providing ground to the front fog lamp relay.
- 5: This step tests if ground is constantly being applied to the front fog lamp relay.
- 6: This step tests if there is opposing voltage present or an open in the front fog lamp relay control circuit.
- 12: After replacement of the BCM you must calibrate the new module for proper operation.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Fog Lights Schematics Connector End View Reference: Lighting Systems Connector End Views or Data Communication Connector End Views | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the front fog lamp relay ON and OFF. Does the front fog lamp relay turn ON and OFF with each command? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
| 3 | Turn OFF the ignition. Disconnect the front fog lamp relay. Turn ON the ignition, with the engine OFF. Probe the battery positive voltage circuit of the front 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 front fog lamp relay and the battery positive voltage circuit of the front fog lamp relay. With a scan tool, command the front 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 front fog lamp relay for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
| 7 | Test the control circuit of the front fog lamp relay for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
| 8 | Inspect for poor connections at the front fog lamp relay. Refer to Circuit Testing and Wiring Repairs . 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 Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 12 |
| 10 | Repair the battery positive voltage circuit of the front fog lamp relay. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 13 | |
| 11 | Replace the front fog lamp relay. Refer to Relay Replacement (Attached to Wire Harness) or Relay Replacement (Within an Electrical Center) . Did you complete the replacement? | Go to Step 13 | |
| 12 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. 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 |
DTC B2530
The numbers below refer to the step numbers on the diagnostic table.
- 2: This step determines if the problem exists in the wiring or the BCM.
- 3: Inspects for poor connections before a component is replaced.
- 4: After replacement of the BCM you must calibrate the new module for proper operation.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Exterior Lights Schematics Connector End View Reference: Lighting Systems Connector End Views or Data Communication Connector End Views | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Test the following circuits as indicated. Refer to Circuit Testing and Wiring Repairs . The backup lamp voltage supply circuit for an open, high resistance, short to voltage or short to ground The backup lamp ground circuit for an open or high resistance Did you find and correct the condition? | Go to Step 5 | Go to Step 3 |
| 3 | Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 5 | Go to Step 4 |
| 4 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 5 | |
| 5 | 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 |
DTC B2550
The numbers below refer to the step numbers on the diagnostic table.
- 3: This step tests for voltage at the voltage supply side of the headlamp low beam relay.
- 4: This step verifies that the BCM is providing ground to the headlamp low beam relay.
- 5: This step tests if ground is constantly being applied to the headlamp low beam relay.
- 6: This step tests if there is opposing voltage present or an open headlamp low beam relay control circuit.
- 12: After replacement of the BCM, you must calibrate the new module for proper operation.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the Daytime Running Lamps ON and OFF. Do the low beam headlamps turn ON and OFF with each command? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
| 3 | Turn OFF the ignition. Disconnect the headlamp low beam relay. Turn ON the ignition, with the engine OFF. Connect a test light between the battery positive voltage circuit of the headlamp low beam relay and 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 low beam relay and the battery positive voltage circuit of the headlamp low beam relay. With a scan tool, command the low beam headlamps 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 low beam relay for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
| 7 | Test the control circuit of the headlamp low beam relay for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
| 8 | Inspect for poor connections at the headlamp low beam relay. Refer to Circuit Testing and Wiring Repairs . 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 Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 12 |
| 10 | Repair the battery positive voltage circuit of the headlamp low beam relay. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 13 | |
| 11 | Replace the headlamp low beam relay. Refer to Relay Replacement (Attached to Wire Harness) or Relay Replacement (Within an Electrical Center) . Did you complete the replacement? | Go to Step 13 | |
| 12 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. 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 |
DTC B2575
The numbers below refer to the step numbers on the diagnostic table.
- 2: Listen for an audible click when the high beam relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
- 3: This step tests for voltage at the coil side of the high beam relay.
- 4: This step verifies that the BCM is providing ground to the high beam relay.
- 5: This step tests if ground is constantly being applied to the high beam relay.
- 6: This step tests if there is opposing voltage present or an open high beam relay control circuit.
- 12: After replacement of the BCM you must calibrate the new module for proper operation.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics Connector End View Reference: Lighting Systems Connector End Views or Data Communication Connector End Views | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the high beam relay ON and OFF. Does the high beam relay turn ON and OFF with each command? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
| 3 | Turn OFF the ignition. Disconnect the high beam relay. Turn ON the ignition, with the engine OFF. Probe the battery positive voltage circuit of the high beam 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 high beam relay and the battery positive voltage circuit of the high beam relay. With a scan tool, command the high beam 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 high beam relay for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
| 7 | Test the control circuit of the high beam relay for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
| 8 | Inspect for poor connections at the high beam relay. Refer to Circuit Testing and Wiring Repairs . 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 Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 12 |
| 10 | Repair the battery positive voltage circuit of the high beam relay. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 13 | |
| 11 | Replace the high beam relay. Refer to Relay Replacement (Attached to Wire Harness) or Relay Replacement (Within an Electrical Center) . Did you complete the replacement? | Go to Step 13 | |
| 12 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. 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 |
DTC B2580
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: This step tests for voltage at the coil side of the park lamp relay.
- 4: This step verifies that the BCM is providing ground to the park lamp relay.
- 5: This step tests if ground is constantly being applied to the park lamp relay.
- 6: This step tests if there is opposing voltage present or an open park lamp relay control circuit.
- 12: After replacement of the BCM you must calibrate the new module for proper operation.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Exterior Lights Schematics Connector End View Reference: Lighting Systems Connector End Views or Data Communication Connector End Views | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the park lamp relay ON and OFF. Does the park lamp relay turn ON and OFF with each command? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
| 3 | Turn OFF the ignition. Disconnect the park lamp relay. Turn ON the ignition, with the engine OFF. Probe the 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 control circuit of the park lamp relay and the 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 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 park lamp relay for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
| 7 | Test the control circuit of the park lamp relay for a short to ground. Refer to Circuit Testing and Wiring Repairs . 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 Circuit Testing and Wiring Repairs . 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 Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 12 |
| 10 | Repair the battery positive voltage circuit of the park lamp relay. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 13 | |
| 11 | Replace the park lamp relay. Refer to Relay Replacement (Attached to Wire Harness) or Relay Replacement (Within an Electrical Center) . Did you complete the replacement? | Go to Step 13 | |
| 12 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. 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 |
DTC B2585
The numbers below refer to the step numbers on the diagnostic table.
- 2: This step test determines by process of elimination which, if any, dimmable component is causing the DTC to set.
- 3: This step test determines if the problem exists in the wiring or the BCM.
- 5: After replacement of the BCM you must calibrate the new module for proper operation.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Interior Lights Dimming Schematics Connector End View Reference: Lighting Systems Connector End Views or Data Communication Connector End Views | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Clear the DTC B2610 with the scan tool. Turn the park lamps ON. Adjust the instrument panel (I/P) dimmer switch to a mid range dimming position. Disconnect each dimmable component from the instrument panel lamps dimming control circuit, one at a time, while monitoring the scan tool current codes. Does DTC B2610 not reset after a particular dimmable component was disconnected? | Go to Step 4 | Go to Step 3 |
| 3 | Test the instrument panel lamps dimming control circuit for an open, high resistance, short to voltage or short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 6 | Go to Step 5 |
| 4 | Replace the dimmable component associated with when the code did not reset. Refer to the proper replacement procedure for that particular component. Did you complete the repair? | Go to Step 6 | |
| 5 | Replace the body control module (BCM). Refer to Control Module References for replacement, setup, and programming. 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 |
DTC B2610
The numbers below refer to the step numbers on the diagnostic table.
- 2: This step test determines if the problem exists in the wiring.
- 3: This step test determines if an open exists in the body wiring harness extension harness.
- 7: After replacement of the BCM you must calibrate the new module for proper operation.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Interior Lights Schematics Connector End View Reference: Lighting Systems Connector End Views or Data Communication Connector End Views | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Test the courtesy lamps supply voltage circuit for an open, high resistance, short to voltage, or short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 8 | Go to Step 3 |
| 3 | Test the truck body controller (TBC) 3 battery positive supply voltage circuit within the body wiring harness extension harness for continuity. Refer to Circuit Testing . Is continuity present? | Go to Step 4 | Go to Step 5 |
| 4 | Inspect for poor connections at the harness connectors of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 8 | Go to Step 7 |
| 5 | Inspect for poor connections at the body wiring harness extension harness connectors. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 8 | Go to Step 6 |
| 6 | Replace the body wiring harness extension harness to the BCM. Refer to Body Wiring Harness Extension Replacement - BCM for replacement, setup, and programming. Did you complete the replacement? | Go to Step 8 | |
| 7 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 8 | |
| 8 | 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 |
DTC B2615
The numbers below refer to the step numbers on the diagnostic table.
- 3: This step tests for the proper operation of the circuit in the low voltage range.
- 4: This step tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
- 5: This step tests for a short to voltage in the 5-volt reference circuit.
- 6: This step tests for a high resistance or an open in the low reference circuit.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Interior Lights Dimming Schematics Connector End View Reference: Lighting Systems Connector End Views or Data Communication Connector End Views | ||||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle | |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With the scan tool, observe the Dimming Input Data parameter in the body control module (BCM) Data List. Does the scan tool indicate that the Dimming Input Data parameter is within the specified range? | 4.5-5.5 V | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
| 3 | Turn OFF the ignition. Disconnect the instrument panel (I/P) dimmer switch. Turn ON the ignition, with the engine OFF. With a scan tool, observe the Dimming Input Data parameter. Does the scan tool indicate that the Dimming Input Data parameter is less than the specified value? | 4.5 V | Go to Step 4 | Go to Step 10 |
| 4 | Turn OFF the ignition. Connect a 3-amp fused jumper wire between the 5-volt reference circuit of the I/P dimmer switch and the signal circuit of the I/P dimmer switch. Turn ON the ignition, with the engine OFF. With a scan tool, observe the Dimming Input Data parameter. Does the scan tool indicate that the Dimming Input Data parameter is greater than the specified value? | 4.86 V | Go to Step 5 | Go to Step 8 |
| 5 | Disconnect the fused jumper wire. Measure the voltage between the 5-volt reference circuit of the I/P dimmer switch and the low reference circuit of the I/P dimmer switch. Does the voltage measure less than the specified value? | 5.15 V | Go to Step 6 | Go to Step 7 |
| 6 | Turn OFF the ignition. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection . Measure the resistance from the low reference circuit of the I/P dimmer switch to a good ground. Does the resistance measure less than the specified value? | 5 ohms | Go to Step 12 | Go to Step 11 |
| 7 | Test the 5-volt reference circuit of the I/P dimmer switch for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 16 | Go to Step 13 | |
| 8 | Test the 5-volt reference circuit of the I/P dimmer switch for the following: An open A high resistance A short to ground Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 16 | Go to Step 9 | |
| 9 | Test the signal circuit of the I/P dimmer switch for the following: An open A high resistance A short to ground Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 16 | Go to Step 13 | |
| 10 | Test the signal circuit of the I/P dimmer switch for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 16 | Go to Step 13 | |
| 11 | Disconnect the BCM. Test the low reference circuit of the I/P dimmer switch for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 16 | Go to Step 13 | |
| 12 | Inspect for poor connections at the harness connector of the I/P dimmer switch. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 16 | Go to Step 14 | |
| 13 | Inspect for poor connections at the harness connector of the BCM. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 16 | Go to Step 15 | |
| 14 | Replace the I/P dimmer switch. Refer to Instrument Panel Dimmer Switch Replacement . Did you complete the replacement? | Go to Step 16 | ||
| 15 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 16 | ||
| 16 | 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 | |
DTC B2620
The numbers below refer to the step numbers on the diagnostic table.
- 2: This step test determines if the problem exists in the wiring or the BCM.
- 3: This step inspects for poor connections before a component is replaced.
- 4: After replacement of the BCM you must calibrate the new module for proper operation.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Interior Lights Dimming Schematics Connector End View Reference: Lighting Systems Connector End Views or Data Communication Connector End Views | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Test the instrument panel lamps dimming control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 5 | Go to Step 3 |
| 3 | Inspect for poor connections at the harness connectors of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 5 | Go to Step 4 |
| 4 | Replace the BCM. Refer to Control Module References . Did you complete the replacement? | Go to Step 5 | |
| 5 | 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 |
DTC B2625
The numbers below refer to the step numbers on the diagnostic table.
- 2: This step verifies that the value displayed is within the specified range.
- 3: This step tests for the proper operation of the circuit in the high voltage range.
- 4: This step tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics Connector End View Reference: Lighting Systems Connector End Views or Data Communication Connector End Views | ||||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle | |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, observe the ambient light sensor parameter in the body control module (BCM) data list. Does the scan tool indicate that the ambient light sensor parameter is within the specified range? | 1.75-4.9 V | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
| 3 | Turn OFF the ignition. Disconnect the ambient light sensor. Turn ON the ignition, with the engine OFF. With a scan tool, observe the ambient light sensor parameter. Does the scan tool indicate that the ambient light sensor parameter is greater than the specified value? | 4.9 V | Go to Step 4 | Go to Step 5 |
| 4 | Turn OFF the ignition. Connect a 3-amp fused jumper wire between the ambient light sensor low reference circuit and the ambient light sensor signal circuit at the ambient light sensor harness connector. Turn ON the ignition, with the engine OFF. With a scan tool, observe the ambient light sensor parameter. Does the scan tool indicate that the ambient light sensor parameter is less than the specified value? | 1.75 V | Go to Step 6 | Go to Step 7 |
| 5 | Test the ambient light sensor signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 10 | |
| 6 | Test the ambient light sensor low reference circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 9 | |
| 7 | Test the ambient light sensor signal circuit for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 8 | |
| 8 | Test the ambient light sensor low reference circuit for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 10 | |
| 9 | 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 . Did you find and correct the condition? | Go to Step 13 | Go to Step 11 | |
| 10 | Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 12 | |
| 11 | Replace the ambient light sensor. Refer to Ambient Light Sensor Replacement . Did you complete the replacement? | Go to Step 13 | ||
| 12 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. 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 | |
DTC B2645
Low Voltage Operation of HID Headlamps
The body control module (BCM) monitors the vehicle's system voltage while in the RUN power mode. When the system voltage drops below 8.9 volts, the following will occur
STAGE 1
If the low beam headlamps are ON, either manually or automatically, the BCM will turn ON the high beam headlamps by activating it's High Beam output.
STAGE 2
When the system voltage drops below 8.5 volts, the following will occur
- If the low beam headlamps are currently ON, either manually or automatically, the BCM will turn OFF the low beam headlamps by deactivating it's Low Beam output.
- If the headlamps are then turned ON manually, the manual switch redundancy will cause the low beam headlamps to remain ON.
If during the same ignition cycle, the BCM enters either STAGE 1 or STAGE 2 operations noted above, and then determines that the system voltage has risen, the following will occur
- If the BCM has entered STAGE 2 operation, it will not return to STAGE 1 operation until the system voltage rises above 9.4 volts.
- If the BCM has entered STAGE 1 operation, it will not return to normal operation until the system voltage rises above 9.8 volts.