Lighting Systems: Diagnosis Chevrolet Silverado 3500 HD

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Diagnostic Starting Point - Lighting

Begin the system diagnosis with the Diagnostic System Check - Vehicle . The Diagnostic System Check - Vehicle will provide the following information

1. The identification of the control modules which command the system
2. The ability of the control modules to communicate through the serial data circuit
3. The identification of any stored diagnostic trouble codes (DTCs) and their status

The Use of the Diagnostic System Check - Vehicle will identify the correct procedure for diagnosing the system and where the procedure is located.

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

Diagnostic Fault Information

Conditions for Running the DTC

Battery Voltage must be between 9-16 volts.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the headlamp switch.
2. Verify that a test lamp illuminates between B+ and the ground circuit terminal 8. If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Dimming Control Signal parameter is less than 0.1 volts. If greater than the specified range, test the signal circuit terminal 13 for a short to voltage. If the circuit tests normal, replace the BCM.
4. Ignition ON, test for B+ between the I/P dimming voltage reference circuit terminal 15 and ground. If less than the specified value, test the voltage reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
5. Install a 3A fused jumper wire between the signal circuit terminal 13 and the voltage reference circuit terminal 15. Verify the scan tool Dimming Control Signal parameter is greater than 2.6 volts. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
6. If all circuits test normal, test or replace the headlamp switch.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. Battery voltage must be between 9-16 volts.
2. Fog lamps ON.

Conditions for Setting the DTC

DTC B2530 00 will set when the BCM detects a short to voltage in the fog lamp relay control circuit for 5 seconds or greater.

Actions Taken When the DTC Sets

When DTC B2530 00 is present, the fog lamps will not operate when the park lamps are ON and the fog lamp switch is active.

Conditions for Clearing the DTC

1. The condition responsible for setting the DTC no longer exists.
2. A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

1. Ignition OFF, disconnect the fog lamp relay.
2. Connect a test lamp between the B+ circuit terminal 85 and the control circuit terminal 86.
3. Command the Fog Lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
4. If all circuits test normal, test or replace the fog lamp relay.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

Battery voltage must be between 9-16 volts.

DTC B2545 00 will set when the BCM detects a short to ground in the backup lamp relay control circuit.

Action Taken When the DTC Sets

When DTC B2545 00 is present, the backup lamps will not operate.

1. The condition responsible for setting the DTC no longer exists.
2. A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

1. Ignition OFF, disconnect the harness connector at the inside rearview mirror.
2. Connect a test lamp between the control circuit terminal 9 and ground.
3. Command the backup lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
4. Ignition OFF, connect the harness connector at the inside rearview mirror. Disconnect the X5 harness connector at the underhood fuse block.
5. Connect a test lamp between the control circuit terminal H8 and ground.
6. Command the Backup Lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
7. If all circuits test normal, replace the underhood fuse block.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. Battery voltage must be between 9-16 volts.
2. Headlamps ON.

DTC B2575 00 will set when the BCM detects a short to voltage in the headlamp low beam relay control circuit.

When DTC B2575 00 is present, the low beam headlamps will not operate.

1. The condition responsible for setting the DTC no longer exists.
2. A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

1. Ignition OFF, disconnect the low beam relay.
2. Connect a test lamp between the control circuit terminal 85 and the B+ circuit terminal 86.
3. Command the Low Beams ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the control circuit for a short to voltage or open/high resistance. If the circuit tests normal, replace the BCM.
4. If all circuits test normal, test or replace the low beam relay.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

Battery voltage must be between 9-16 volts.

DTC B257A 00 will set when the BCM detects a short to ground on the headlamp switch headlamps OFF signal circuit or the headlamp switch headlamps ON signal circuit.

1. When DTC B257A 00 is present on the headlamp switch headlamps OFF signal circuit, the low beam headlamps are always ON in the AUTO position. The headlamp switch operates in all positions other than AUTO. The AUTO headlamp defeat is inoperative.
2. When DTC B257A 00 is present on the headlamp switch headlamps ON signal circuit, the low beam headlamps are always ON. The BCM disregards all headlamp switch inputs.

1. The condition responsible for setting the DTC no longer exists.
2. A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

1. Ignition OFF, disconnect the X2 harness connector at the BCM.
2. Connect a test lamp between B+ and the signal circuit terminal 17.
3. Turn the headlamp switch between the headlamp AUTO and headlamp OFF positions. The test lamp should turn ON and OFF as the switch is cycled. If the test lamp is always OFF, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the headlamp switch. If the test lamp is always ON, test the signal circuit for a short to ground. If the circuit tests normal, replace the headlamp switch.
4. Connect a test lamp between B+ and the signal circuit terminal 12.
5. Turn the headlamp switch to the ON and OFF positions. The test lamp should turn ON and OFF as the switch is cycled. If the test lamp is always OFF, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the headlamp switch. If the test lamp is always ON, test the signal circuit for a short to ground. If the circuit tests normal, replace the headlamp switch.
6. If all circuits test normal, replace the BCM.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. Battery voltage must be between 9-16 volts.
2. Headlamps ON.

DTC B2580 00 will set when the BCM detects a short to voltage in the headlamp high beam relay control circuit.

When DTC B2580 00 is present, the high beam headlamps and flash to pass (FTP) will not operate.

1. The condition responsible for setting the DTC no longer exists.
2. A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

1. Ignition OFF, disconnect the X4 harness connector at the underhood fuse block.
2. Connect a test lamp between the control circuit terminal C3 and B+.
3. Command the High Beams ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the control circuit for a short to voltage or open/high resistance. If the circuit tests normal, replace the BCM.
4. If all circuits test normal, replace the underhood fuse block.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. Battery voltage must be between 9-16 volts.
2. Park lamps ON.

DTC B2585 00 will set when the BCM detects a short to voltage in the PARK LAMP Relay control circuit.

When DTC B2585 00 is present, the park lamps will not operate.

1. The condition responsible for setting the DTC no longer exists.
2. A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

1. Ignition OFF, disconnect the PARK LAMP Relay.
2. Connect a test lamp between the relay control circuit terminal 86 and the B+ circuit terminal 85.
3. Command the parking lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the relay control circuit for a short to ground. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the relay control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
4. If all circuits test normal, test or replace the PARK LAMP Relay.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. Battery voltage must be between 9-16 volts.
2. Headlamp switch in AUTO position.

DTC B2600 00 will set when the BCM detects a short to voltage in the DRL relay control circuit.

The BCM will disable the DRL relay control circuit.

1. The condition responsible for setting the DTC no longer exists.
2. A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

1. Ignition OFF, disconnect the X4 harness connector at the underhood fuse block.
2. Connect a test lamp between the control circuit terminal H4 and B+.
3. Command the DRL ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
4. If all circuits test normal, replace the underhood fuse block.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. Battery voltage must be between 9-16 volts.
2. Park lamps ON.

DTC B2610 00 will set when the BCM detects a short to ground in the LED backlight dimming control circuit.

The BCM will not dim or illuminate any indicators supplied by the LED backlight dimming control circuit.

1. The condition responsible for setting the DTC no longer exists.
2. A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

1. Ignition OFF, disconnect the harness connector at the appropriate component.
2. Verify that a test lamp illuminates between the listed ground circuit terminal and B+. Left steering wheel switch terminal 8 Right steering wheel switch terminal 1 PTO switch terminal 5 Trailer brake controller switch terminal 8 DIC switch terminal 5 HVAC control module terminal 10 X2 I/P multifunction switch terminal 3 If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the listed LED dimming control circuit terminal and ground. Left steering wheel switch terminal 6 Right steering wheel switch terminal 2 PTO switch terminal 6 Trailer brake controller switch terminal 7 DIC switch terminal 4 HVAC control module terminal 1 X2 I/P multifunction switch terminal 4
4. Command the dimming test high to low with a scan tool. The test lamp should turn from bright to dim when changing between the commanded states. If the test lamp is always off, test the control circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the BCM. If the test lamp is always bright, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the appropriate component.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

The ignition is ON, the BCM, driver door switch, and passenger door switch attempt to illuminate the courtesy lamps.

The BCM, driver door lock and side window switch, or passenger door lock and side window switch detects a short to ground, short to voltage, or open on the courtesy lamp voltage supply circuit.

The BCM, driver door lock and side window switch, and passenger door lock and side window switch cease attempts to illuminate the courtesy lamps.

1. The conditions for setting the DTC are no longer present.
2. A history DTC clears after 100 malfunction-free ignition cycles.

1. Ignition OFF, disconnect the harness connector at the inoperative lamp.
2. Test for less than 5.0 ohms between the ground circuit terminal and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the control circuit terminal and the ground circuit terminal.
4. Ignition ON, command the Courtesy Lamps output control ON and OFF with the scan tool. The test lamp should turn ON and OFF. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the inoperative lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. Battery voltage must be between 9-16 volts.
2. Park lamps ON.

DTC B2625 00 will set when the BCM detects a short to ground in the LED indicator dimming control circuit.

When DTC B2625 00 is present, the BCM will not illuminate the LEDs supplied by the LED indicator dimming control circuit.

1. The condition responsible for setting the DTC no longer exists.
2. A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

1. Ignition OFF, disconnect the harness connector at the appropriate component.
2. Connect a test lamp between the listed LED dimming control circuit terminal and ground. IP multifunction switch terminal 6 4wd mode switch terminal 4 PTO switch terminal 7
3. Command the dimming test high to low with a scan tool. The test lamp should turn from bright to dim when changing between the commanded states. If the test lamp is always OFF, test the control circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the BCM. If the test lamp is always bright, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
4. If all circuits test normal, test or replace the appropriate component.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

Battery voltage must be between 9-16 volts.

1. Automatic lamp control (ALC) is inoperative.
2. The BCM defaults to low light status and commands the low beam headlamps ON.

1. The condition responsible for setting the DTC no longer exists.
2. A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

1. Ignition OFF, disconnect the harness connector at the ambient light sensor.
2. Ignition OFF, scan tool OFF, doors CLOSED, test for less than 5.0 ohms between the appropriate ground circuit terminal listed below and ground. Terminal B - with C67/C42 Terminal C - with CJ2 If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Ambient Light Sensor parameter is greater than 4.5 volts. If less than the specified range, test the appropriate signal circuit terminal listed below for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. Terminal A - with C67/C42 Terminal D - with CJ2
4. Install a 3A fused jumper wire between the appropriate signal circuit terminal listed below and ground. Verify the scan tool Ambient Light Sensor parameter is less than 0.196 volts. Terminal A - with C67/C42 Terminal D - with CJ2 If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM
5. If all circuits test normal, replace the ambient light sensor.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. Battery voltage must be between 9-16 volts.
2. Park lamps ON.

The BCM detects a short to ground in the I/P lamps dimmer switch signal circuit.

The BCM will not DIM or illuminate any I/P lamps supplied by the I/P lamps dimmer switch signal circuit.

1. The condition responsible for setting the DTC no longer exists.
2. A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

1. Ignition OFF, disconnect the harness connector at the appropriate component.
2. Ignition OFF, verify that a test lamp illuminates between the listed ground circuit terminal and B+. Headlamp Switch terminal 8 Sunroof switch terminal 5 Front door lock switch terminal B - w/o AN3 Driver window switch terminal A X2 - w/o AN3 Front passenger window switch terminal F - w/o AN3 OSRVM switch terminal G - w/o AN3 Transfer case shift control switch terminal 6 Roof beacon switch terminal 1 Sliding rear window switch terminal D Rear window switch terminal F If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the listed backlighting control circuit terminal and ground. Headlamp Switch terminal 7 Sunroof switch terminal 3 Front door lock switch terminal A - w/o AN3 Driver window switch terminal 1 X1 - w/o AN3 Front passenger window switch terminal B - w/o AN3 OSRVM switch terminal E - w/o AN3 Transfer case shift control switch terminal 5 Roof beacon switch terminal 2 Sliding rear window switch terminal E Rear window switch terminal B
4. Command the Dimming Test high to low with a scan tool. The test lamp should turn from bright to dim when changing between the commanded states. If the test lamp is always OFF, test the control circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the BCM. If the test lamp is always bright, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the appropriate component.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. Battery voltage must be between 9-16 volts.
2. Brakes APPLIED.

The DTC will set when the BCM detects a short to ground in the CHMSL control circuit when the stop lamps are being commanded ON.

The BCM will not illuminate the CHMSL.

1. The condition responsible for setting the DTC no longer exists.
2. A history DTC will clear once 100 malfunction-free ignition cycles have occurred.

Diagnostic Aids

1. Ignition OFF, disconnect the harness connector at the CHMSL.
2. Test for less than 5.0 ohms between the ground circuit terminal B and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the control circuit terminal A and the ground circuit terminal B.
4. Ignition ON, command the stop lamps ON and OFF by applying and releasing the brake pedal. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, replace the CHMSL.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

Battery voltage must be between 9-16 volts.

DTC B3600 03 will set when the BCM detects a short to ground or an open/high resistance in the I/P dimmer switch signal circuit.

1. The I/P dimmer switch will not operate.
2. The I/P dimming lamps will not illuminate.

1. The condition responsible for setting the DTC no longer exists.
2. A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

1. Ignition OFF, disconnect the harness connector at the headlamp switch.
2. Verify that a test lamp illuminates between the ground circuit terminal 8 and B+. If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Dimming Control Signal parameter is less than 0.1 volts. If greater than the specified range, test the signal circuit terminal 13 for a short to voltage. If the circuit tests normal, replace the BCM.
4. Ignition ON, test for B+ between the I/P dimming voltage reference circuit terminal 15 and ground. If less than the specified value, test the voltage reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
5. Install a 3A fused jumper wire between the signal circuit terminal 13 and the voltage reference circuit terminal 15. Verify the scan tool BCM Dimming Control Signal parameter is greater than 2.6 volts. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
6. If all circuits test normal, test or replace the headlamp switch.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. The ignition is ON.
2. The stop lamps must be commanded ON.

The BCM detects a short to ground in the CHMSL relay control circuit when the stop lamps are commanded ON.

The CHMSL does not illuminate.

1. The conditions for setting the DTC are no longer present.
2. A history DTC clears after 100 malfunction-free ignition cycles.

1. Ignition OFF, disconnect the harness connectors at the center high mounted stop lamp.
2. Test for less than 5.0 ohms between the ground circuit terminal B and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the stop lamp control circuit terminal A and ground circuit terminal B.
4. Ignition ON, press and release the brake pedal. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to voltage. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance.
5. If all circuits test normal, test or replace the center high mounted stop lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

Battery voltage must be between 9-16 volts.

In the event that DTC C0277, C0297, or C0890 sets as current in the body control module (BCM) is an indication of a possible internal BCM malfunction or programming error. There are no external circuits available to diagnose on this vehicle with respect to these DTCs.

When DTC C0277 is set as current, the vehicle may not start.

1. For DTC C0277 the ignition must be cycled before the code can be cleared.
2. A history DTC will clear once 50 malfunction-free ignition cycles have occurred.
3. A DTC will not clear the current status until the next ignition cycle.

These DTCs may set as current after the replacement of an electronic brake control module (EBCM) or engine control module (ECM). If a control module has been replaced, ensure that the programming procedure and all recalibration procedures have been completed successfully before addressing these DTCs.

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the Lighting System. Refer to «Checking Aftermarket Accessories»(ref-317172-S31262273302009060900000) .
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. «Backup Lamps Malfunction (Automatic Transmission)»(ref-317143-S02366784942009060900000) or «Backup Lamps Malfunction (Manual Transmission)»(ref-317143-S24146517062009060900000)
2. «Courtesy Lamps Malfunction»(ref-317143-S33004636482009060900000)
3. «Daytime Running Lamps Malfunction»(ref-317143-S33057539682009060900000)
4. «Front Fog Lamps Malfunction»(ref-317143-S29690888992009060900000)
5. «Hazard Lamps Malfunction»(ref-317143-S36694670012009060900000)
6. «Headlamps Malfunction»(ref-317143-S20224757782009060900000)
7. «Interior Backlighting Malfunction (w/AN3)»(ref-317143-S29695488222009060900000) or «Interior Backlighting Malfunction (w/o AN3)»(ref-317143-S00981650532009060900000)
8. «Park, License, and/or Tail Lamps Malfunction»(ref-317143-S17622776972009060900000)
9. «Stop Lamps Malfunction»(ref-317143-S16667232192009060900000)
10. «Turn Signal Lamps and/or Indicators Malfunction»(ref-317143-S13731855372009060900000)

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. Ignition OFF, disconnect the X2 harness connector at the underhood fuse block.
2. Ignition OFF, exterior lamps OFF, test for less that 5.0 ohms between the ground circuit terminal N5 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
3. Connect the X2 harness connector at the underhood fuse block. Disconnect the X5 harness connector at the underhood fuse block.
4. Connect a test lamp between the control circuit terminal H8 and ground.
5. Command the Backup Lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
6. Ignition OFF, connect the X5 harness connector at the underhood fuse block. Disconnect the harness connector at the inoperative backup lamp.
7. Ignition OFF, exterior lamps OFF, test for less than 5.0 ohms between the ground circuit terminal GRD and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
8. Connect a test lamp between the control circuit terminal MJR and ground.
9. Command the Backup Lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the underhood fuse block. If the test lamp is always OFF and the circuit fuse is good, test the control circuit for an open/high resistance. If the circuit tests normal, replace the underhood fuse block. If the test lamp is always OFF and the circuit fuse is open, test the control circuit for a short to ground. If the circuit tests normal, replace the underhood fuse block.
10. If all circuits test normal, test or replace the inoperative backup lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

LED Dimming Circuit Test

1. Ignition OFF, disconnect the harness connector at the appropriate component.
2. Verify that a test lamp illuminates between the listed ground circuit terminal and battery voltage. Right steering wheel switch terminal 1 Left steering wheel switch terminal 8 DIC switch terminal 5 Manual HVAC control module terminal 10 X2 Multifunction accessory switch terminal 3 If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the listed LED dimming control circuit terminal and ground. Right steering wheel switch terminal 2 Left steering wheel switch terminal 6 Power take off switch terminal 6 Trailer brake controller switch terminal 7 IPC terminal 8 Radio terminal 7 X1 DIC switch terminal 4 Manual HVAC control module terminal 1 X2 Multifunction accessory switch terminal 4
4. Command the dimming test high to low with a scan tool. The test lamp should turn from bright to dim when changing between the commanded states. If the test lamp is always off, test the control circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the BCM. If the test lamp is always bright, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the appropriate component.

Front Door Switch Backlighting Circuit Test

1. Ignition OFF, disconnect the harness connector X4 at the door lock and side window switch.
2. Connect a 3A fused jumper wire between the low reference circuit terminal 4 and ground.
3. Connect a test lamp between the backlight supply voltage circuit terminal 13 and B+. The heated seat switch backlighting should illuminate. If the switch backlighting does not illuminate, replace the heated seat switch.
4. If the switch backlighting tests normal, replace the door lock and side window switch.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

Dimmer Switch Circuit Test

1. Ignition OFF, disconnect the harness connector at the headlamp switch.
2. Ignition OFF, verify that a test lamp illuminates between the ground circuit terminal 8 and B+. If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Dimming Control Signal parameter is less than 0.1 volts. If greater than the specified range, test the signal circuit terminal 13 for a short to voltage. If the circuit tests normal, replace the BCM.
4. Ignition ON, test for B+ between the I/P dimming voltage reference circuit terminal 15 and ground. If less than the specified value, test the voltage reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
5. Install a 3A fused jumper wire between the signal circuit terminal 13 and the voltage reference circuit terminal 15. Verify the scan tool BCM Dimming Control Signal parameter is greater than 2.6 volts. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
6. If all circuits test normal, test or replace the headlamp switch.

Interior Backlighting Circuit Test

1. Ignition OFF, disconnect the harness connector at the affected component.
2. Ignition OFF, verify that a test lamp illuminates between the listed ground circuit terminal and battery voltage. Passenger window switch terminal F Headlamp switch terminal 8 Transfer case control switch terminal 6 Sunroof switch terminal 5 Door lock switch terminal B Roof beacon switch terminal 1 Sliding rear window switch terminal D Garage door opener switch terminal 3 Outside rear view mirror switch terminal G Driver window switch terminal A X2 If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the listed backlighting control circuit terminal and ground. Passenger window switch terminal B Headlamp switch terminal 7 Transfer case control switch terminal 5 Sunroof switch terminal 3 Door lock switch terminal A Roof beacon switch terminal 2 Sliding rear window switch terminal E Garage door opener switch terminal 2 Outside rear view mirror switch terminal E Driver window switch terminal 1 X1
4. Command the dimming test high to low with a scan tool. The test lamp should turn from bright to dim when changing between the commanded states. If the test lamp is always off, test the control circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the BCM. If the test lamp is always bright, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the affected component.

1. Ignition OFF, disconnect the harness connector at the affected component.
2. Ignition OFF, verify that a test lamp illuminates between the listed ground circuit terminal and battery voltage. Right steering wheel switch terminal 1 Left steering wheel switch terminal 8 DIC switch terminal 5 Manual HVAC control module terminal 10 X2 Multifunction accessory switch terminal 3 If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the listed LED dimming control circuit terminal and ground. Right steering wheel switch terminal 2 Left steering wheel switch terminal 6 Power take off switch terminal 6 Trailer brake controller switch terminal 7 IPC terminal 8 Radio terminal 7 X1 DIC switch terminal 4 Manual HVAC control module terminal 1 X2 Multifunction accessory switch terminal 4
4. Command the dimming test high to low with a scan tool. The test lamp should turn from bright to dim when changing between the commanded states. If the test lamp is always off, test the control circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the BCM. If the test lamp is always bright, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the affected component.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

Park Lamp Switch Circuit Test

1. Ignition OFF, disconnect the harness connector at the headlamp switch.
2. Test for less than 1.0 ohm between the ground circuit terminal 8 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool parklamp switch parameter is inactive. If not the specified value, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the BCM.
4. Install a 3A fused jumper wire between the signal circuit terminal 2 and ground. Verify the scan tool BCM parklamp switch parameter is active. If not the specified value, test the signal circuit for a short to voltage or open/high resistance. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the headlamp switch.

Park Lamp Relay Circuit Test

1. Ignition OFF, disconnect the PARK LAMP Relay.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 30 and ground. If the test lamp does not illuminate, replace the underhood fuse block.
3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 86 and ground. If the test lamp does not illuminate, replace the underhood fuse block.
4. Connect a test lamp between the relay control circuit terminal 85 and the B+ circuit terminal 86.
5. Command the parking lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the relay control circuit for a short to ground. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the relay control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
6. If all circuits test normal, test or replace the PARK LAMP Relay.

Exterior Lamps Circuit Test

1. Ignition OFF, disconnect the harness connector at the appropriate park, marker, license, or tail lamp.
2. Verify that a test lamp illuminates when connected between B+ and the listed ground circuit terminal. Front park lamp terminal G Tail lamp terminal GRD Marker and clearance lamps terminal A License lamp terminal B If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Ignition ON, connect a test lamp between the listed control circuit terminal and ground. Front park lamp terminal MAJ Tail lamp terminal MNR Marker and clearance lamps terminal B License lamp terminal A
4. Command the parking lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the appropriate lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

Stop Lamp Switch Circuit Test

1. Ignition OFF, disconnect the harness connector at the stop lamp switch.
2. Ignition ON, test for B+ between the 12-volt reference circuit terminal C and ground. If less than the specified range, test the 12-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
3. Verify the scan tool BCM Stop Lamp Switch Status parameter is approximately 1023 counts. If not the specified value, test the signal circuit terminal D for a short to voltage. If the circuit tests normal, replace the BCM.
4. Install a 3A fused jumper wire between the signal circuit terminal D and the 12-volt reference circuit terminal C. Verify the scan tool Stop Lamp Switch Status parameter is 1 count. If not the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the stop lamp switch.

Brake Switch Circuit Test

1. Ignition OFF, disconnect the harness connector at the stop lamp switch.
2. Ignition ON, test for B+ between the ignition supply circuit terminal B and ground. If less than the specified range, test the ignition supply circuit for a short to ground or an open/high resistance.
3. Verify the scan tool TCM Brake Switch parameter is Released. If not the specified value, test the signal circuit terminal A for a short to voltage.
4. Install a 3A fused jumper wire between the signal circuit terminal B and the ignition supply circuit terminal A. Verify the scan tool Brake Switch parameter is Applied. If not the specified value, test the signal circuit for an open/high resistance.
5. If all circuits test normal, test or replace the stop lamp switch.

Stop Lamp Circuit Test

1. Ignition OFF, disconnect the harnes connector X4 at the BCM.
2. Ignition ON, verify a test lamp illuminates between the terminals listed below and ground. Terminal 1 Terminal 2 Terminal 4 If the test lamp does not illuminate, test the B+ circuit for an open/high resistance or short to ground.
3. Connect the harness connector X4 at the BCM.
4. Ignition OFF, disconnect the harness connector at the appropriate stop lamp.
5. Test for less than 1 ohm between the ground circuit terminal GRD and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
6. Connect a test lamp between the stop lamp control circuit terminal MJR and ground.
7. Ignition ON, press and release the brake pedal. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to voltage. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance.
8. If all circuits test normal, test or replace the appropriate stop lamp.

CHMSL Relay Control Circuit Test

1. Ignition OFF, disconnect the harness connector X5 at the BCM.
2. Ignition ON, verify the center high mount stop lamp is not on. If the center high mount stop lamp is on, test the CHMSL relay control circuit terminal 5 for a short to voltage. If the circuit tests normal replace the underhood fuse block.
3. Install a 10A fused jumper wire between the CHMSL relay control circuit terminal 5 and B+. Verify the center high mount stop lamp is on. If the center high mount stop lamp is not on or the fuse in the jumper wire opens, test the CHMSL relay control circuit for a short to ground or an open/high resistance. If the circuit tests normal replace the underhood fuse block.
4. If all circuits test normal, replace the BCM.

CHMSL Circuit Test

1. Ignition OFF, disconnect the harnes connector at the center high mount stop lamp.
2. Test for less than 1 ohm between the ground circuit terminal 1 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the control circuit terminal A and the ground circuit terminal B.
4. Ignition ON, press and release the brake pedal. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to voltage. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance.
5. If all circuits test normal, test or replace the center high mounted stop lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-317170-S03444519162009060900000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-317170-S02898624092009060900000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-317170-S23773585642009060900000) provides an overview of each diagnostic category.

An open CTSY fuse located in the I/P fuse block will affect the operation of the right front turn signal only.