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Contents Wiring diagrams Section: Exterior Lights All sections

Lighting Systems Chevrolet Colorado I

Exterior Lights 14 illustrations ~20616 words

Fastener Tightening Specifications

ApplicationSpecification
MetricEnglish
Door Jamb Switch Screw1.5 N.m13 lb in
Front Fog Lamp Bolts (Canyon)10 N.m88 lb in
Front Fog Lamp Bolts (XTREME)2 N.m18 lb in
Headlamp Bolts to Radiator Support10 N.m88 lb in
Headlamp Switch Screw2.5 N.m22 lb in
High Mount Stop Lamp Lens Screws2.5 N.m22 lb in
Tail Lamp Assembly to Vehicle Screws1.9 N.m17 lb in

Fastener Tightening Specifications

Scheme 1

Scheme 1: Headlights/Daytime Running Lights (DRL) Schematics
Scheme 1: Headlights/Daytime Running Lights (DRL) Schematics

Scheme 2

Scheme 2
Scheme 2

Scheme 3

Scheme 3: Fog Lights Schematics
Scheme 3: Fog Lights Schematics

Scheme 4

Scheme 4: Exterior Lights Schematics
Scheme 4: Exterior Lights Schematics

Scheme 5

Scheme 5
Scheme 5

Scheme 6

Scheme 6
Scheme 6

Scheme 7

Scheme 7
Scheme 7

Scheme 8

Scheme 8
Scheme 8

Scheme 9

Scheme 9: Interior Lights Schematics
Scheme 9: Interior Lights Schematics

Scheme 10

Scheme 10
Scheme 10

Scheme 11

Scheme 11: Interior Lights Dimming Schematics
Scheme 11: Interior Lights Dimming Schematics

DIAGNOSTIC CODE INDEX

DTCDescription
DTC B0525B0525: Left Turn Signal Circuit
DTC B0527, B0528, or B0529B0527: Right Turn Signal Circuit Low B0528: Right Turn Signal Circuit High B0529: Right Turn Signal Circuit Open
DTC B0530B0530: Right Turn Signal Circuit
DTC B0532, B0533, or B0534B0532: Left Turn Signal Circuit Low B0533: Left Turn Signal Circuit High B0534: Left Turn Signal Circuit Open
DTC B2532 or B2533B2532: Front Fog Lamps Control Circuit Low B2533: Front Fog Lamps Control Circuit High
DTC B2557 or B2558B2557: Passenger Compartment Lamp Control Circuit Low B2558: Passenger Compartment Lamp Control Circuit High
DTC B2575B2575: Headlamp Control Circuit
DTC B2582 or B2583B2582: Headlamp High Beam Control Circuit Low B2583: Headlamp High Beam Control Circuit High
DTC B2585B2585: Park Lamp Control Circuit
DTC B2602 or B2603B2602: Daytime Running Lamp Control Circuit Low or Open B2603: Daytime Running Lamp Control Circuit High
DTC B2622 or B2623B2622: Dimming Display Pulse Width Modulation (PWM) Input Circuit Low B2623: Dimming Display Pulse Width Modulation (PWM) Input Circuit High
DTC B2624B2624: Dimming Display Pulse Width Modulation (PWM) Input Circuit Open
DTC B2647 or B2648B2647: Ambient Light Sensor Circuit Low B2648: Ambient Light Sensor Circuit High

DIAGNOSTIC CODE INDEX

Begin the system diagnosis with the Diagnostic System Check - Vehicle . The Diagnostic System Check 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 DTCs and their status

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

Diagnostic Instructions

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit/System Description

When the body control module (BCM) receives a left turn signal ON command from the turn signal switch, the BCM will apply voltage to the left turn signal indicator supply voltage circuit. The turn signal flasher, which is integrated within the BCM, will flash the left turn signal indicator lamp in the instrument panel cluster (IPC) simultaneously with the turn signal lamps.

Conditions for Running the DTC

The battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

When the BCM receives a left turn signal command and the left turn signal indicator supply voltage circuit is open, shorted to ground, or shorted to voltage

Action Taken When the DTC Sets

The left turn signal indicator in the IPC will not operate or will remain always on.

Conditions for Clearing the DTC

  1. This DTC will clear on current status after the condition for setting the fault is corrected.
  2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.

Reference Information

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for Scan Tool Information

Circuit/System Verification

Ignition ON, operate the left turn signal and verify that the left turn indicator flashes.

  1. If the left turn indicator does not illuminate or remains illuminated perform the Left Turn Indicator Circuit Test.

Circuit/System Testing

Left Turn Indicator Circuit Test

  1. Ignition OFF, disconnect the harness connector at the IPC.
  2. Verify that a test lamp illuminates when connected from battery voltage to the ground circuit terminal 4. If the test lamp does not illuminate test the ground circuit for an open/high resistance.
  3. Connect a test lamp between the control circuit terminal 6 and the ground circuit terminal 4.
  4. Ignition ON, operate the left turn signal and verify that the test lamp flashes. 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 IPC.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM or IPC replacement, programming, and setup.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Right Front Turn Signal ControlB0527B0529B0528
Right Rear Turn Signal ControlB0527B0529B0528
Low ReferenceB0529

DTC B0527, B0528, or B0529

When the body control module (BCM) receives a right turn signal ON command from the turn signal switch, the BCM will apply voltage to the right rear stop/turn lamp control circuit and right turn signal lamps control circuit. The turn signal flasher is integrated within the BCM and will flash both circuits simultaneously.

The battery voltage must be between 9-16 volts.

B0527

When the BCM receives a right turn signal command and the right front or rear turn lamp control circuit is shorted to ground.

B0528

When the BCM receives a right turn signal command and the right front or rear turn lamp control circuit is shorted to voltage.

B0529

When the BCM receives a right turn signal command and the right front or rear turn lamp control circuit is open.

The right front and/or right rear turn signals will not operate or will remain always on.

  1. This DTC will clear on current status after the condition for setting the fault is corrected.
  2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for Scan Tool Information

Ignition ON, operate the right turn signal and verify that the right front and rear turn signals flash.

  1. If the right turn indicator does not illuminate or remains illuminated perform the Right Turn Signal Circuit Test.

Right Turn Signal Circuit Test

  1. Ignition OFF, disconnect the harness connector at the affected turn signal bulb.
  2. Verify that a test lamp illuminates when connected from battery voltage to the ground circuit terminal G. If the test lamp does not illuminate 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 G.
  4. Ignition ON, operate the right turn signal and verify that the test lamp flashes. 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 bulb.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Park/Turn Signal/Side Marker Lamp Bulb Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  2. «Tail Lamp Bulb Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  3. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, programming, and setup.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When the body control module (BCM) receives a right turn signal ON command from the turn signal switch, the BCM will apply voltage to the right turn signal indicator supply voltage circuit. The turn signal flasher, which is integrated within the BCM, will flash the right turn signal indicator lamp in the instrument panel cluster (IPC) simultaneously with the turn signal lamps.

The battery voltage must be between 9-16 volts.

When the BCM receives a right turn signal command and the right turn signal indicator supply voltage circuit is open, shorted to ground, or shorted to voltage

The right turn signal indicator in the IPC will not operate or will remain always on.

  1. This DTC will clear on current status after the condition for setting the fault is corrected.
  2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for Scan Tool Information

Ignition ON, operate the right turn signal and verify that the right turn indicator flashes.

  1. If the right turn indicator does not illuminate or remains illuminated perform the Right Turn Indicator Circuit Test.

Right Turn Indicator Circuit Test

  1. Ignition OFF, disconnect the harness connector at the IPC.
  2. Verify that a test lamp illuminates when connected from battery voltage to the ground circuit terminal 4. If the test lamp does not illuminate test the ground circuit for an open/high resistance.
  3. Connect a test lamp between the control circuit terminal 7 and the ground circuit terminal 4.
  4. Ignition ON, operate the right turn signal and verify that the test lamp flashes. 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 IPC.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM or IPC replacement, programming, and setup.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Left Front Turn Signal ControlB0532B0534B0533
Left Rear Turn Signal ControlB0532B0534B0533
Low ReferenceB0534

DTC B0532, B0533, or B0534

When the body control module (BCM) receives a left turn signal ON command from the turn signal switch, the BCM will apply voltage to the left rear stop/turn lamp control circuit and left turn signal lamps control circuit. The turn signal flasher is integrated within the BCM and will flash both circuits simultaneously.

The battery voltage must be between 9-16 volts.

B0532

When the BCM receives a left turn signal command and the left front or rear turn lamp control circuit is shorted to ground.

B0533

When the BCM receives a left turn signal command and the left front or rear turn lamp control circuit is shorted to voltage.

B0534

When the BCM receives a left turn signal command and the left front or rear turn lamp control circuit is open.

The left front and/or left rear turn signals will not operate or will remain always on.

  1. This DTC will clear on current status after the condition for setting the fault is corrected.
  2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for Scan Tool Information

Ignition ON, operate the left turn signal and verify that the left front and rear turn signals flash.

  1. If the left turn indicator does not illuminate or remains illuminated perform the Left Turn Signal Circuit Test.

Left Turn Signal Circuit Test

  1. Ignition OFF, disconnect the harness connector at the affected turn signal bulb.
  2. Verify that a test lamp illuminates when connected from battery voltage to the ground circuit terminal G. If the test lamp does not illuminate 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 G.
  4. Ignition ON, operate the left turn signal and verify that the test lamp flashes. 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 bulb.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Park/Turn Signal/Side Marker Lamp Bulb Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  2. «Tail Lamp Bulb Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  3. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, programming, and setup.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Front Fog Lamp Relay ControlB25321B2533
Low Reference1
1. Front Fog Lamps Inoperative

DTC B2532 or B2533

When the body control module (BCM) senses that the front fog lamp switch signal circuit is grounded momentarily by pressing the front fog lamp switch, the BCM energizes the front fog lamp relay by applying battery voltage to the front fog lamp relay control circuit.

The battery voltage must be between 9-16 volts.

B2532

When the BCM receives a front fog lamp switch on command and the front fog lamp relay control circuit is shorted to ground.

B2533

When the BCM receives a front fog lamp switch off command and the front fog lamp relay control circuit is shorted to voltage.

The front fog lamps will not operate or will remain always on.

  1. This DTC will clear on current status after the condition for setting the fault is corrected.
  2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for Scan Tool Information

Ignition ON, operate the front fog lamp switch on and off and verify that the front fog lamps turn on and off.

  1. If the front fog lamps do not turn on or remain always on perform the Front Fog Lamp Relay Control Circuit Test.

Front Fog Lamp Relay Control Circuit Test

  1. Ignition OFF, disconnect the front fog lamp relay.
  2. Verify that a test lamp illuminates when connected from battery voltage to the relay coil ground circuit terminal 86. If the test lamp does not illuminate test the ground circuit for an open/high resistance.
  3. Connect a test lamp between the relay coil control circuit terminal 85 and the ground circuit terminal 86.
  4. Ignition ON, operate the front fog lamp switch on and off and verify that the test lamp turns 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 relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)
  2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, programming, and setup.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Courtesy Lamp SupplyB25571
Courtesy Lamp Control21B2558
1. Courtesy Lamps Inoperative 2. Courtesy Lamps Always On

DTC B2557 or B2558

The interior courtesy lamps consist of the dome lamp and the left and right footwell lamps. Battery voltage is supplied to the courtesy lamps by the body control module (BCM) through an inadvertent power supply circuit. In the event that any of these lamps were to remain illuminated for a period of more than 20 minutes with the ignition switch in the OFF position, the BCM will deactivate the inadvertent power supply to prevent a total battery discharge condition. Courtesy lamp operation is controlled by the BCM through low side drive control circuits, and any time the inadvertent power supply is active the BCM turns on the courtesy lamps by grounding the control circuits.

The battery voltage must be between 9-16 volts.

B2557

The courtesy lamp supply circuit is shorted to ground.

B2558

The courtesy lamp control circuit is shorted to voltage.

The courtesy lamps will not operate or will remain always on.

  1. This DTC will clear on current status after the condition for setting the fault is corrected.
  2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for Scan Tool Information

Ignition ON, command the courtesy lamps on and off with a scan tool.

  1. If the courtesy lamps do not turn on or remain always on perform the Courtesy Lamp Control Circuit Test.

Courtesy Lamp Control Circuit Test

  1. Ignition OFF, disconnect the affected courtesy or dome lamp.
  2. Ignition ON, command the courtesy lamps on and off with a scan tool.
  3. Verify that a test lamp turns on and off when connected from battery voltage to the control circuit terminal B. If the test lamp is always OFF, test the control circuit for an open/high resistance. If the test lamp is always ON, test the control circuit for a short to ground.
  4. Connect a test lamp between the supply circuit terminal A and ground.
  5. Ignition ON, verify that the test lamp illuminates. If the test lamp is always OFF, test the supply 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 bulb.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Dome Lamp Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, programming, and setup.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When the body control module (BCM) senses a headlamp on request from the headlamp switch, the BCM sends a ground signal to the headlamp relay through the low beam headlamp relay control circuit. The headlamp relay will illuminate the low beam headlamps.

The battery voltage must be between 9-16 volts.

The headlamp relay control circuit is shorted to voltage.

The headlamps will be inoperative from the headlamp switch.

  1. This DTC will clear on current status after the condition for setting the fault is corrected and the ignition is cycled.
  2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for Scan Tool Information

Ignition ON, command the headlamps on and off with a scan tool and verify that the headlamps turn on and off.

  1. If the headlamps do not turn on or remain always on perform the Headlamp Relay Control Circuit Test.

Headlamp Relay Control Circuit Test

  1. Ignition OFF, disconnect the headlamp relay.
  2. Connect a test lamp between the relay coil control circuit terminal 86 and battery voltage.
  3. Ignition ON, command the headlamps on and off with a scan tool and verify that the test lamp turns 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.
  4. If all circuits test normal, test or replace the relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)
  2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, programming, and setup.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Headlamp High Beam Relay ControlB2582B2583B2583
Low ReferenceB2583

DTC B2582 or B2583

When the body control module (BCM) receives a ground signal from the multifunction high beam or flash to pass (FTP) switch commanding to illuminate the high beam headlamps, the BCM will energize the high beam relay by applying battery voltage to the high beam relay control circuit.

The battery voltage must be between 9-16 volts.

B2582

When the BCM receives a high beam switch on command and the front fog lamp relay control circuit is shorted to ground.

B2583

When the BCM receives a high beam switch off command and the front fog lamp relay control circuit is shorted to voltage.

The high beam headlamps will not operate or will remain always on.

  1. This DTC will clear on current status after the condition for setting the fault is corrected.
  2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for Scan Tool Information

Ignition ON, operate the high beam headlamps on and off and verify that the high beam headlamps turn on and off.

  1. If the high beam headlamps do not turn on or remain always on perform the High Beam Relay Control Circuit Test.

High Beam Relay Control Circuit Test

  1. Ignition OFF, disconnect the high beam relay.
  2. Verify that a test lamp illuminates when connected from battery voltage to the relay coil ground circuit terminal 85. If the test lamp does not illuminate test the ground circuit for an open/high resistance.
  3. Connect a test lamp between the relay coil control circuit terminal 86 and the ground circuit terminal 85.
  4. Ignition ON, operate the high beam switch on and off and verify that the test lamp turns 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 relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)
  2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, programming, and setup.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When the body control module (BCM) receives a ground signal from the headlamp switch commanding to illuminate the park lamps, the BCM will energize the park lamp relay by grounding the park lamp relay control circuit.

The battery voltage must be between 9-16 volts.

The park lamp relay control circuit is shorted to voltage.

The park lamps will be inoperative from the headlamp switch.

  1. This DTC will clear on current status after the condition for setting the fault is corrected.
  2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for Scan Tool Information

Ignition ON, command the park lamps on and off with a scan tool and verify that the park lamps turn on and off.

  1. If the park lamps do not turn on or remain always on perform the Park Lamp Relay Control Circuit Test.

Park Lamp Relay Control Circuit Test

  1. Ignition OFF, disconnect the park lamp relay.
  2. Connect a test lamp between the relay coil control circuit terminal 86 and battery voltage.
  3. Ignition ON, command the park lamps on and off with a scan tool and verify that the test lamp turns 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.
  4. If all circuits test normal, test or replace the relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)
  2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, programming, and setup.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
DRL Control CircuitB2602B2602B2603

DTC B2602 or B2603

The daytime running lights (DRL) relay is controlled by the body control module (BCM). Battery positive voltage is applied to the relay coil at all times. The BCM grounds the DRL relay control circuit in order to turn ON the DRL relay illuminating the low beam headlamps at a reduced intensity.

  1. The ignition switch is in the RUN position.
  2. The headlamp switch is in the AUTO position.
  3. The park brake is not applied.
  4. The gear selector is not in the PARK position.

One of the following conditions must occur

  1. The DRL relay control circuit is open, shorted to ground, or shorted to voltage.
  2. The DRL relay coil is open.
  3. The battery positive voltage to the DRL relay is open.
  1. The BCM disables the DRL relay control as long as the fault is present.
  2. The BCM disables the DRL relay control until the next key cycle after the fault is corrected.
  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.

Diagnostic Aids

  1. The park brake must not be set and the transmission must be is gear for the DRL to operate property.
  2. An open, short to ground, or a short to voltage in the following location may cause a malfunction to occur: The control circuit of the DRL relay coil The DRL relay The BCM

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, carefully supply sufficient light to the ambient light sensor to activate DRL mode. The BCM Output Data List should indicate that the DRL Status is On. The low beam headlamps should illuminate at a reduced intensity.

  1. Ignition OFF, disconnect the DRL relay.
  2. Ignition ON, verify that a test lamp illuminates between the relay coil voltage supply circuit and ground. If the test lamp does not illuminate, repair the voltage supply circuit for a short to ground or an open/high resistance. If the voltage supply circuit fuse is open, test the relay switch control circuit for a short to ground. If the circuit tests normal, test or replace the DRL relay.
  3. Disconnect the harness connector at the BCM.
  4. Test for infinite resistance between the DRL relay control circuit and ground If less than infinite, test the DRL relay control circuit for a short to ground.
  5. Connect the harness connector at the BCM.
  6. Connect a test lamp between the relay coil control circuit and the relay coil voltage supply circuit.
  7. Cycle the key OFF and then ON. Perform the Circuit/System Verification. The test lamp should turn ON. If the test lamp remains OFF all the time, test for a short to voltage or an open/high resistance on the relay coil control circuit. If the circuit tests normal, replace the BCM. If the test lamp remains ON all the time, test for a short to ground on the relay coil control circuit. If the circuit tests normal, replace the BCM.
  8. If all circuits test normal, test or replace the DRL relay.

Component Testing

Relay Test

  1. Ignition OFF, disconnect the DRL relay.
  2. Test for 65 to 95 ohms of resistance between terminals 85 and 86. If the resistance is not within the specified range, replace the relay.
  3. Test for infinite resistance between the following terminals: 30 and 86 30 and 87 30 and 85 85 and 87 If less than infinite resistance, replace the relay.
  4. Test for less than 2 ohms of resistance between terminals 30 and 87A. If greater than 2 ohms, replace the relay.
  5. Install a 10-amp fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Measure for less than 2 ohms of resistance between terminals 30 and 87. If greater than 2 ohms, replace the relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)
  2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The body control module (BCM) receives a variable voltage signal from the instrument panel (I/P) dimmer switch requesting to illuminate the I/P controls illumination lamps to a desired intensity. When this occurs, the BCM directly sends a variable voltage based on the I/P dimmer switch position through the I/P lamps supply voltage circuit to the I/P controls illumination lamps.

The battery voltage must be between 9-16 volts.

B2622

When the BCM receives an I/P controls illumination lamp request signal and the I/P lamps supply voltage circuit is shorted to ground.

B2623

When the BCM is not receiving an I/P controls illumination lamp request signal and the I/P lamps supply voltage circuit is shorted to voltage.

The I/P controls illumination lamps will not operate or are always on.

  1. This DTC will clear on current status after the condition for setting the fault is corrected.
  2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for Scan Tool Information

  1. Ignition ON, operate the parklamp switch to the ON position.
  2. Verify that the instrument panel backlighting dims and goes to full brightness while operating the dimmer switch to dim and full bright. If the instrument panel backlighting lamps do not turn on or remain always on perform the IP Backlighting Lamp Control Circuit Test.
  1. Ignition OFF, disconnect the BCM connector X2.
  2. Ignition ON, verify that the following components backlighting is not illuminated. Accessory switch Hazard switch HVAC control module terminal Rear window wiper/washer switch Radio Sunroof switch Headlamp switch If any of the listed components backlighting is illuminated, test the associated control circuit for a short to voltage.
  3. Connect a fused jumper wire from battery voltage to the following terminals and verify associated backlighting operation. Accessory switch A27 Hazard switch A28 HVAC control module terminal A29 Rear window wiper/washer switch A30 Radio A33 Sunroof switch A34 Headlamp switch A36 If the jumper fuse opens while connected to any of the listed terminals, test the associated control circuit for a short to ground.
  4. If all circuits test normal, replace the BCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, programming, and setup.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The body control module (BCM) directly sends a reference voltage to the instrument panel (I/P) dimmer switch which is then reduced based on the I/P dimmer switch position and monitored as a signal to the BCM. The BCM uses this signal to directly control the desired level of I/P illumination lamp intensity.

The battery voltage must be between 9-16 volts.

When the BCM monitors a signal voltage equal to or greater than 4.86 volts for more than one second.

The I/P illumination lamp dimming will not operate.

  1. This DTC will clear on current status after the condition for setting the fault is corrected.
  2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool dimming potentiometer while turning the dimmer switch from dim to bright. The reading should change between 0.6 to 4.5 volts.

  1. Ignition OFF, disconnect the harness connector at the headlamp switch.
  2. Test for less than 5 ohms between the ground circuit terminal 3 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify the scan tool dimming potentiometer is greater than 4.5 volts. If not the specified value, test the signal circuit terminal 14 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 14 and the ground circuit terminal 3. Verify the scan tool dimming potentiometer is less than 0.6 volts. If not the specified value, 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, test or replace the headlamp switch.
  1. Ignition OFF, disconnect the harness connector at the headlamp switch.
  2. Test for 500-4.5k ohms between the signal terminal 14 and the low reference terminal 3 while turning the dimmer switch from dim to bright. If not the specified value, replace the headlamp switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Headlamp Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Ambient Light Sensor SignalB2647B2648B2648
Low ReferenceB2648

DTC B2647 or B2648

The body control module (BCM) monitors the ambient light sensor signal circuit in order to determine if the daytime running lights (DRL) or the auto headlights (ALC) should be turned ON in the AUTO mode. When the BCM senses the ambient light sensor signal voltage is between 1.75-4.9 volts, either the DRL will be commanded ON or the ALC will be commanded ON depending upon the amount of light received by the sensor.

The system voltage must be between 9-16 volts.

B2647

When the ambient light sensor signal voltage is less than 1.75 volts.

B2648

When the ambient light sensor signal voltage is greater than 4.9 volts.

The ALC will remain always ON or always OFF in any ambient light state.

  1. This DTC will clear immediately after the condition for setting the fault is corrected.
  2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for Scan Tool Information

Ignition ON, observe the scan tool ambient light sensor parameter. The reading should be between 1.75 and 4.9 volts.

  1. Ignition OFF, disconnect the harness connector at the ambient light sensor.
  2. Ignition OFF, test for less than 1 ohm of resistance between the low reference circuit terminal B and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the BCM.
  3. Ignition ON, verify the scan tool ambient light sensor parameter is greater than 4.9 volts. If less than the specified range, test the signal circuit terminal A 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 A and the low reference circuit terminal B. Verify the scan tool ambient light sensor parameter is less than 0.5 volts. 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, test or replace the ambient light sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Ambient Light Sensor Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, programming, and setup.
IMPORTANTThe following steps must be completed before using the symptom tables.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) before using the Symptom Tables in order to verify that all of the following are true: There are no DTCs set. The control modules can communicate via the serial data link.
  2. Review the system operation and circuit descriptions that apply to the customer complaint in order to familiarize yourself with the system functions. Refer to the following list: «Exterior Lighting Systems Description and Operation»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems) «Interior Lighting Systems Description and Operation»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)

Visual/Physical Inspection

  1. Inspect for aftermarket devices which could affect the operation of the lighting system. Refer to «Checking Aftermarket Accessories»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__checking-aftermarket-accessories) .
  2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Symptom List

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

  1. «Backup Lamps Malfunction»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  2. «Cargo Lamps Malfunction»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  3. «Courtesy Lamps Malfunction»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  4. «Daytime Running Lamps Malfunction»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  5. «Front Fog Lamp Indicator Malfunction»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  6. «Front Fog Lamps Malfunction»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  7. «Hazard Lamps Malfunction»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  8. «Headlamps Malfunction»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  9. «Headlamps Flash to Pass Inoperative»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  10. «High Beam Indicator Malfunction»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  11. «Interior Backlighting Malfunction»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  12. «Park, License, and/or Tail Lamps Malfunction»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  13. «Stop Lamps Malfunction»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  14. «Turn Signal Lamps and/or Indicators Malfunction»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The BCK/UP fuse in the underhood fuse block supplies battery positive voltage to the normally open park/neutral position (PNP) switch of a vehicle equipped with an automatic transmission or the backup lamp switch if equipped with a manual transmission. When the driver places the gear selector lever is in the REVERSE position, the switch closes and the current flow is from the switch to the backup lamps.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for Scan Tool Information

  1. Ignition ON, with the transmission in park or neutral the backup lamps should not be on.
  2. Shift the transmission into reverse, the backup lamps should be on.
  1. Ignition OFF, disconnect the park neutral position or backup lamp switch connector.
  2. Ignition ON, the backup lamps should not be illuminated. If the backup lamps are illuminated, test the listed backup lamp control circuit for a short to voltage. Park neutral position switch terminal 10 Backup lamp switch terminal B
  3. Connect a test lamp between the listed switch supply circuit and ground. The test lamp should illuminate. Park neutral position switch terminal 11 Backup lamp switch terminal A If the test lamp does not illuminate, test the switch supply circuit for an open/high resistance or short to ground.
  4. Connect a fused jumper wire between the listed switch supply circuit and backup lamp control circuit. Both backup lamps should illuminate. Park neutral position switch terminal 11 to terminal 10 Backup lamp switch terminal A to terminal B If both backup lamps are not illuminated, test the backup lamp control circuit for a open/high resistance or short to ground. If one backup lamp is not illuminated test the affected control and ground circuits for an open/high resistance. If the circuits test normal replace the affected backup lamp bulb.
  5. If all circuits test normal, test or replace the park neutral position or backup lamp switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Park/Neutral Position and Backup Lamp Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/automatic-trans/#how-to-overhaul-the-automatic-transmission-4l60-e4l65-e4l70-e-removal-installation-service-troubleshooting-diagnosis)
  2. «Park/Neutral Position and Backup Lamp Switch Adjustment»(/chevrolet/colorado/i-2004-2012/remont/automatic-trans/#how-to-overhaul-the-automatic-transmission-4l60-e4l65-e4l70-e-removal-installation-service-troubleshooting-diagnosis__parkneutral-position-and-backup-lamp-switch)
  3. «Backup Lamp Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-trans/#manual-transmission-aisin-ar5)
  4. «Backup Lamp Bulb Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Cargo Lamp Switch Signal12
Cargo Lamp Control2
Cargo Lamp Ground22
1. Cargo Lamps Always On 2. Cargo Lamps Inoperative

Cargo Lamps Malfunction

The cargo lamp on the vehicle exterior is supplied voltage by a dedicated courtesy lamp supply voltage circuit. Cargo lamp operation is controlled by a push-button switch on the instrument panel (I/P) that sends a momentary ground signal to the BCM. The BCM will then illuminate the cargo lamp only while the dome lamp is illuminated.

Verify proper operation of the courtesy and dome lamps prior to diagnosing a cargo lamp condition.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, verify that the cargo lamp switch parameter displays active and inactive while pressing and releasing the cargo lamp switch. If the scan tool parameter does not display the correct state in relation to the actual switch position, refer to Cargo Lamp Switch Circuit Test below.
  2. If the circuits test normal refer to the Cargo Lamp Control Circuit Test below.

Cargo Lamp Switch Circuit Test

  1. Ignition OFF, disconnect the headlamp switch connector.
  2. Test for less than 5 ohms between the low reference circuit terminal 3 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance.
  3. Ignition ON, verify that the scan tool cargo lamp switch parameter displays inactive. If the parameter displays active test the switch signal circuit 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 10 and the ground circuit terminal 3. Verify the scan tool cargo lamp switch parameter displays active. If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  5. If the circuits test normal test or replace the headlamp switch.

Cargo Lamp Control Circuit Test

  1. Ignition OFF, disconnect the harness connector at the affected cargo lamp bulb.
  2. Test for less than 5 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. Turn the dome lamp switch on and operate the cargo lamp switch ON and OFF. 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 an open/high resistance or short to ground. If the circuit tests normal, replace the BCM.
  5. If all circuits test normal, test or replace the affected bulb.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Headlamp Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Interior Lamp Switch Signal12
Courtesy Lamp Supply2
Courtesy Lamp Control12
1. Courtesy Lamps Always On 2. Courtesy Lamps Inoperative

Courtesy Lamps Malfunction

The interior courtesy lamps consist of the dome lamp and the left and right footwell lamps. Battery voltage is supplied to the courtesy lamps by the body control module (BCM) through an inadvertent power supply circuit. In the event that any of these lamps were to remain illuminated for a period of more than 20 minutes with the ignition switch in the OFF position, the BCM will deactivate the inadvertent power supply to prevent a total battery discharge condition. Courtesy lamp operation is controlled by the BCM through low side drive control circuits, and any time the inadvertent power supply is active the BCM turns on the courtesy lamps by grounding the control circuits. The BCM will activate the courtesy lamps using inputs from the dome lamp switch on the headlamp switch assembly or any of the door jamb switches. The dome lamp switch signal is monitored from battery voltage by the BCM and when the switch is turned on the signal circuit will be closed to the headlamp switch low reference circuit. The door jamb switch signals are monitored from battery voltage by the BCM and when a door is opened the signal circuit will be grounded through the door jamb switch.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Verify that the courtesy lamp switch parameter displays active and inactive while operating the dimming control/courtesy lamp switch on and off. If the scan tool parameter does not display the correct state in relation to the actual switch position, refer to Courtesy Lamp Switch Circuit Test below.
  2. Verify that the driver door ajar switch parameter displays door open and door closed while opening and closing the driver door. If the scan tool parameter does not display the correct state in relation to the actual switch position, refer to Driver Door Jamb Switch Circuit Test. below
  3. Verify that the passenger door ajar switch parameter displays door open and door closed while opening and closing the front passenger door and rear passenger doors. If the scan tool parameter does not display the correct state in relation to the actual switch position, refer to Passenger Door Jamb Switch Circuit Test below.
  4. If the circuits test normal refer to Courtesy Lamp Control Circuit Test below.

Courtesy Lamp Switch Circuit Test

  1. Ignition OFF, disconnect the headlamp switch connector.
  2. Test for less than 5 ohms between the low reference circuit terminal 3 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance.
  3. Ignition ON, verify that the scan tool courtesy lamp switch parameter displays inactive. If the parameter displays active test the switch signal circuit 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 11 and the ground circuit terminal 3. Verify the scan tool courtesy lamp switch parameter displays active. If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  5. If the circuits test normal test or replace the headlamp switch.

Driver Door Jamb Switch Circuit Test

  1. Ignition OFF, disconnect the harness connector at the driver door jamb switch.
  2. Test for less than 5 ohms between the ground circuit terminal 2 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify the scan tool driver door ajar switch parameter is door closed. If not the specified value, test the signal circuit terminal 1 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 1 and the ground circuit terminal 2. Verify the scan tool driver door ajar switch parameter is door ajar. If not the specified value, 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, test or replace the driver door ajar switch.

Passenger Door Jamb Switch Circuit Test

  1. Ignition OFF, disconnect the harness connector at the affected door jamb switch.
  2. Test for less than 5 ohms between the ground circuit terminal 2 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify the scan tool passenger door ajar switch parameter is door closed. If not the specified value, test the signal circuit terminal 1 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 1 and the ground circuit terminal 2. Verify the scan tool passenger door ajar switch parameter is door ajar. If not the specified value, 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, test or replace the affected door jamb switch.

Courtesy Lamp Control Circuit Test

  1. Ignition OFF, disconnect the harness connector at the affected courtesy or dome lamp bulb.
  2. Ignition ON, verify that a test lamp illuminates between the lamp supply circuit terminal A and ground. If the test lamp does not illuminate, test the courtesy lamp supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the BCM.
  3. Connect a test lamp between the control circuit terminal B and courtesy lamp supply circuit terminal A.
  4. Operate the courtesy lamp switch ON and OFF. 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 affected bulb.

Courtesy Lamp Switch Test

  1. Ignition OFF, disconnect the harness connector at the headlamp switch.
  2. Test for infinite resistance between the signal terminal 11 and the low reference terminal 3 with the courtesy lamp switch in the off position. If not the specified value, replace the headlamp switch.
  3. Test for less than 5 ohms between the signal terminal 11 and the low reference terminal 3 with the courtesy lamp switch in the on position. If greater than the specified range, replace the headlamp switch.

Door Jamb Switch Test

  1. Ignition OFF, disconnect the harness connector at the door jamb switch.
  2. Test for infinite resistance between the signal terminal 1 and the ground terminal 2 with the switch in the open position. If not the specified value, replace the door jamb switch.
  3. Test for less than 5 ohms between the signal terminal 1 and the ground terminal 2 with the switch in the closed position. If greater than the specified range, replace the door jamb switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Headlamp Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Daytime Running Lamp Control112
DRL Relay Control21
Ambient Light Sensor SignalB2647B2648B2648
Ambient Light Sensor Low ReferenceB2648
1. Daytime running lamps inoperative 2. Daytime running lamps always on

Daytime Running Lamps Malfunction

The ambient light sensor is a light sensitive transistor that varies its voltage signal to the body control module (BCM) in response to changes to the outside (ambient) light level. When the BCM receives this signal, it will either turn ON the daytime running lamps (DRL) or the headlamps for auto headlamp operation. Any function or condition that turns ON the headlights will cancel the DRL operation. With the headlight switch in the AUTO position, the headlights will either be turned ON or OFF, after an approximate 8 second delay depending on whether daylight or low light conditions are sensed. When the ambient light sensor signals the BCM for DRL operation in daylight conditions, the BCM illuminates the low beam headlamps at a reduced intensity utilizing the DRL relay. The DRL will operate when the ignition switch is in the RUN position, the headlamp and panel dimmer switch is in the AUTO position, the gear selector is not in the PARK position, and the parking brake is released. When these conditions have been met and the ambient light sensor indicates daytime conditions, the DRL will illuminate.

Verify that the headlamps operate normal in the manual mode prior to diagnosing a DRL condition.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for Scan Tool Information

Ignition ON, command the daytime running lamps ON and OFF with a scan tool. The daytime running lamps should turn on and off.

  1. Ignition OFF, disconnect the DRL relay.
  2. Ignition ON, verify that a test lamp does not illuminate between the daytime running lamp control circuit terminal 87 and ground. If the test lamp illuminates, test the control circuit for a short to voltage.
  3. Verify that a test lamp illuminates between the B+ circuit terminal 30 and ground. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the DRL circuit fuse is open, test the control circuit terminal 87 for a short to ground. If the circuit tests normal, test or replace the DRL relay.
  4. Verify that a test lamp illuminates between the B+ circuit terminal 86 and ground. If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.
  5. Connect a 10A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87. Verify the DRL headlamps are on. If the DRL headlamps are not on, test the control circuit for an open/high resistance.
  6. Connect a test lamp between the B+ circuit terminal 86 and the relay control circuit terminal 85.
  7. Command the daytime running 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.
  8. If all circuits test normal, test or replace the DRL relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, programming, and setup.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Front Fog Lamp Indicator Control112
1. Front fog lamp indicator inoperative. 2. Front fog lamp indicator always on.

Front Fog Lamp Indicator Malfunction

With both the ignition switch in the RUN position and the park lamps or low beam head lamps ON, the fog lights will illuminate when the driver presses the fog lamp switch. When the fog lamps are on the BCM will turn the fog lamp indicator on by supplying battery voltage to the indicator LED through the indicator control circuit. The indicator is grounded through the headlamp switch low reference circuit to the BCM.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for Scan Tool Information

Ignition ON, command the front fog lamps ON and OFF with a scan tool. The front fog lamp indicator should turn on and off.

  1. Ignition OFF, disconnect the harness connector at the headlamp switch.
  2. Ignition ON, headlamps ON, connect a test lamp between the indicator control circuit terminal 8 and ground. The test lamp should not be illuminated. If the test lamp is illuminated, test the indicator control circuit for a short to voltage. If the circuit tests normal replace the BCM.
  3. Command the front fog lamps ON with a scan tool. The test lamp should be illuminated. If the test lamp is not illuminated, test the indicator control circuit for an open/high resistance or short to ground. If the circuit tests normal replace the BCM.
  4. If all the circuits test normal replace the headlamp switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Headlamp Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Fog Lamp Relay ControlB25321B2533
Fog lamp Control112
Fog Lamp Switch Signal211
Headlamp Switch Low Reference3
Relay Coil Ground1
Fog Lamp Ground1
1. Front Fog Lamps Inoperative 2. Front Fog Lamps Always On 3. All Headlamp Switch Functions Inoperative

Front Fog Lamps Malfunction

With both the ignition switch in the RUN position and the park lamps or low beam head lamps ON, the fog lights will illuminate when the driver presses the fog lamp switch. The FOG LP fuse in the underhood fuse block supplies battery positive voltage to the fog lamps. With the headlamp switch is in either the park or headlamp position and the fog lamp switch is pressed, the body control module (BCM) will energize the fog lamp relay control circuit. The current flow is from the fog lamp relay to both front fog lamps and to ground G105. The state of the fog lamps, either ON or OFF, will remain the same until the fog lamp switch is pressed again, or the ignition switch is cycled OFF and ON. Fog lamp operation will be cancelled whenever the park lamps are turned OFF or the high beam headlights have been selected.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, command the front fog lamps ON and OFF with a scan tool. The front fog lamps should turn on and off. If the fog lamps do not turn on and off, refer to Fog Lamp Relay Circuit Test below.
  2. Ignition ON, observe the scan tool front fog lamp switch parameter while pressing the front fog lamp switch. The reading should change between inactive and active. If not the specified value, refer to Fog Lamp Switch Circuit Test below.

Fog Lamp Relay Circuit Test

  1. Ignition OFF, disconnect the front fog lamp relay.
  2. Test for less than 5 ohms between the relay coil ground circuit terminal 86 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify a test lamp does not illuminate between the fog lamp control circuit terminal 30 and ground. If the test lamp illuminates, test the fog lamp control circuit for a short to voltage.
  4. Verify a test lamp illuminates between the relay switch B+ circuit terminal 87 and ground. If the test lamp does not illuminate, replace the underhood fuse block.
  5. Disconnect the harness connector at an affected fog lamp.
  6. Ignition OFF, test for less than 5 ohms between the ground circuit terminal B and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
  7. Connect the harness connector at the fog lamp.
  8. Ignition ON, connect a 15A fused jumper wire between the relay switch B+ circuit terminal 87 and the fog lamp control circuit terminal 30. Verify the front fog lamps are on. If the front fog lamps do not turn on, test the fog lamp control circuit for an open/high resistance. If the circuit tests normal, test or replace the affected fog lamp bulb. If the fuse in the jumper wire opens, test the fog lamp control circuit for a short to ground.
  9. Connect a test lamp between the relay coil control circuit terminal 85 and ground.
  10. Command the front 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 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 open/high resistance. If the circuit tests normal, replace the BCM.
  11. If all circuits test normal, test or replace the front fog lamp relay.

Fog Lamp Switch Circuit Test

  1. Ignition OFF, disconnect the harness connector at the headlamp switch.
  2. Ignition ON, verify the scan tool front fog lamp switch parameter is inactive. If not the specified value, test the signal circuit terminal 7 for a short to ground. If the circuit tests normal, replace the BCM.
  3. Install a 3A fused jumper wire between the signal circuit terminal 7 and the low reference circuit terminal 3. Verify the scan tool front fog lamp switch parameter is active. If not the specified value, test the signal 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 headlamp switch.

Relay Test

  1. Ignition OFF, disconnect the front fog lamp relay.
  2. Test for 70-100 ohms between terminals 85 and 86. If the resistance is not within the specified range, replace the relay.
  3. Test for infinite resistance between the following terminals: 30 and 85 30 and 86 30 and 87 85 and 87 If not the specified value, replace the relay.
  4. Install a 10A fused jumper wire between relay terminal 85 and B+. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87. If greater than the specified range, replace the relay.

Fog Lamp Switch Test

  1. Ignition OFF, disconnect the harness connector at the headlamp switch.
  2. Test for infinite resistance between the signal terminal 7 and the low reference terminal 3. If not the specified value, replace the headlamp switch.
  3. Test for less than 5 ohms between the signal terminal 7 and the low reference terminal 3 while pressing the front fog lamp switch. If greater than the specified range, replace the headlamp switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)
  2. «Front Fog Lamp Bulb Replacement (Canyon)»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  3. «Headlamp Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  4. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Hazard Switch Signal21
Turn Signal Lamp ControlB0527, B0532B0528, B0533B0528, B0533
Hazard Switch Low Reference1
Turn Signal Lamp Ground1
1. Hazard Lamps Inoperative 2. Hazard Lamps Always On

Hazard Lamps Malfunction

When the hazard switch is pressed, the hazard switch signal circuit is grounded and the BCM will activate and flash all turn signal lamps including both IPC turn indicators. The front and rear turn signals are grounded at G105.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool hazard lamp switch parameter while operating the hazard switch on and off. The reading should change between active and inactive.

  1. Ignition OFF, disconnect the harness connector at the hazard switch.
  2. Test for less than 5 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. Ignition ON, verify the scan tool hazard lamp switch parameter is inactive. If not the specified value, test the signal circuit terminal C 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 C and the ground circuit terminal B. Verify the scan tool hazard lamp switch parameter is active. If not the specified value, 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, test or replace the hazard switch.

Fog Lamp Switch Test

  1. Ignition OFF, disconnect the harness connector at the hazard switch.
  2. Test for infinite resistance between the signal terminal C and the low reference terminal B. If not the specified value, replace the hazard switch.
  3. Test for less than 5 ohms between the signal terminal C and the low reference terminal B while pressing the hazard switch. If greater than the specified range, replace the hazard switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Hazard Warning Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Headlamp On Switch Signal58
Headlamp Dimmer Switch High Beam Signal23
Headlamp Off Switch Signal99
LH Headlamp Control445
RH Headlamp Control445
Headlamp High/Low Beam Relay ControlB2582B2583B2583
Headlamp Relay Control51B2575
High Beam Headlamp Control73
Low Beam Headlamp Control62
Headlamp Switch Low Reference1
Headlamp High/Low Beam Relay Ground1
1. Low and High Beam Headlamps Inoperative 2. Low Beam Headlamps Inoperative 3. High Beam Headlamps Inoperative 4. Left or Right Headlamp Inoperative in Low an High Beam 5. Low Beam Headlamps Always On 6. Low Beam headlamps on With High Beams 7. High Beam headlamps on With Low Beams 8. Manual Headlamps Function Inoperative 9. Auto Headlamps Disable Function Inoperative

Headlamps Malfunction

The ambient light sensor is a light sensitive transistor that varies its voltage signal to the body control module (BCM) in response to changes to the outside (ambient) light level. When the BCM receives this signal, it will either turn ON the daytime running lamps (DRL) or the headlamps for auto headlamp operation. Any function or condition that turns ON the headlights will cancel the DRL operation. With the headlight switch in the AUTO position, the headlights will either be turned ON or OFF, after an approximate 8 second delay depending on whether daylight or low light conditions are sensed. When the ambient light sensor signals the BCM for DRL operation in daylight conditions, the BCM illuminates the low beam headlamps at a reduced intensity utilizing the DRL relay. The DRL will operate when the ignition switch is in the RUN position, the headlamp and panel dimmer switch is in the AUTO position, the gear selector is not in the PARK position, and the parking brake is released. When these conditions have been met and the ambient light sensor indicates daytime conditions, the DRL will illuminate.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, observe the scan tool Headlamp Off Switch parameter while cycling the headlamp switch between the Auto and Off positions. The parameter should cycle between Active while in the Off position and Inactive when released. If the parameter does not cycle between the specified values, refer to Headlamp Switch Circuit Test below.
  2. Observe the scan tool Headlamp On Switch parameter while cycling the headlamp switch between the Auto and Head position. The parameter should cycle between Active and Inactive. If the parameter does not cycle between the specified values, refer to Headlamp Switch Circuit Test below.
  3. With the headlamps ON, observe the scan tool High Beam Select Switch parameter while switching the headlamp dimmer switch between the low and high beam positions. The parameter should cycle between Active and Inactive. If the parameter does not cycle between the specified values, refer to Turn Signal/Multifunction Switch Circuit Test below.
  4. Command the Headlamps ON and OFF with a scan tool. Verify the low beam headlamps turn ON and OFF. If the low beam headlamps do not cycle between the commanded states, refer to Low Beam Headlamp Circuit Test below.
  5. Command the High Beams ON and OFF with a scan tool. Verify the high beam headlamps turn ON and OFF. If the high beam headlamps do not cycle between the commanded states, refer to High Beam Headlamp Circuit Test below.

Headlamp Switch Circuit Test

  1. Ignition OFF, disconnect the harness connector at the headlamp switch.
  2. Verify that a test lamp illuminates between the ground circuit terminal 3 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 Headlamp On Switch parameter is Inactive. If not the specified value, test the signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the BCM.
  4. Verify the scan tool Headlamp Off Switch parameter is Inactive. If not the specified value, test the signal circuit terminal 5 for a short to ground. If the circuit tests normal, replace the BCM.
  5. Install a 3A fused jumper wire between the signal circuit terminal 4 and ground. Verify the scan tool Headlamp On Switch parameter is Active. If not the specified value, test the signal circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the BCM.
  6. Install a 3A fused jumper wire between the signal circuit terminal 5 and ground. Verify the scan tool Headlamp Off Switch parameter is Active. If not the specified value, test the signal circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the BCM.
  7. If all circuits test normal, test or replace the headlamp switch.

Turn Signal/Multifunction Switch Circuit Test

  1. Ignition OFF, disconnect the X204 harness connector at the turn signal/multifunction switch.
  2. Verify that a test lamp illuminates between the ground circuit terminal B10 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 High Beam Select Switch parameter is Inactive. If not the specified value, test the signal circuit terminal A11 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 A11 and ground. Verify the scan tool High Beam Select Switch parameter is Active. If not the specified value, test the signal circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the BCM.
  5. If all circuits test normal, test or replace the turn signal/multifunction switch.

Low Beam Headlamp Circuit Test

  1. Ignition OFF, disconnect the HDLP relay.
  2. Ignition ON, verify that a test lamp does not illuminate between the relay control circuit terminal 85 and B+. If the test lamp illuminates, test the relay control circuit for a short to ground. If the circuit tests normal replace the BCM.
  3. Verify that the test lamp illuminates when the scan tool Headlamps control is commanded ON. If the test lamp does not illuminate, test the relay control circuit for an open/high resistance. If the circuit tests normal replace the BCM.
  4. Disconnect the HI/LO BEAM relay.
  5. Verify that a test lamp illuminates between the relay ground circuit terminal 30 and B+. If the test lamp does not illuminate, test the relay ground circuit for an open/high resistance.
  6. Ignition ON, verify that a test lamp does not illuminate between the relay control circuit terminal 86 and ground. If the test lamp illuminates, test the relay control circuit for a short to voltage. If the circuit tests normal replace the BCM.
  7. Install the HDLP and HI/LO BEAM relays.
  8. Disconnect the affected headlamp bulb.
  9. Ignition ON, verify that a test lamp illuminates between the low beam control circuit terminal A and B+. If the test lamp does not illuminate, test the control circuit for an open/high resistance. If the circuit tests normal replace the HI/LO BEAM relay.
  10. Connect a test lamp between the affected headlamp control circuit terminal B and ground.
  11. Verify that the test lamp illuminates when the scan tool Headlamps control is commanded ON. If the test lamp does not illuminate, test the control circuit for an open/high resistance or short to ground. If the circuit tests normal replace the HDLP relay.
  12. If all the circuits test normal replace the affected headlamp bulb.

High Beam Headlamp Circuit Test

  1. Ignition OFF, disconnect the HI/LO BEAM relay.
  2. Ignition ON, Verify that a test lamp illuminates between the HI/LO BEAM relay control circuit terminal 86 and ground when the scan tool High Beams control is commanded ON. If the test lamp does not illuminate, test the control circuit for an open/high resistance or short to ground. If the circuit tests normal replace the BCM.
  3. install the HI/LO BEAM relay.
  4. Disconnect the affected headlamp bulb.
  5. Connect a test lamp between the high beam control circuit terminal B and B+.
  6. Ignition ON, verify that the test lamp illuminates when the scan tool High Beams control is commanded ON. If the test lamp does not illuminate, test the control circuit for an open/high resistance. If the circuit tests normal replace the HI/LO BEAM relay.
  7. If all the circuits test normal replace the affected headlamp bulb.

Headlamp Switch Test

  1. Ignition OFF, disconnect the harness connector at the headlamp switch.
  2. Test for infinite resistance between the off signal terminal 5 and the low reference terminal 3 with the headlamp switch in the Auto position. If not the specified value, replace the headlamp switch.
  3. Test for less than 5 ohms between the off signal terminal 5 and the low reference terminal 3 with the headlamp switch in the Off position. If greater than the specified range, replace the headlamp switch.
  4. Test for infinite resistance between the on signal terminal 4 and the low reference terminal 3 with the headlamp switch in the Auto position. If not the specified value, replace the headlamp switch.
  5. Test for less than 5 ohms between the on signal terminal 4 and the low reference terminal 3 with the headlamp switch in the On position. If greater than the specified range, replace the headlamp switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Headlamp Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  2. «Turn Signal Multifunction Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/steering-column-switches/#steering-wheel-steering-column)
  3. «Headlamp Bulb Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  4. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The flash to pass switch simultaneously activates the headlamps on signal and the high beam signal inputs to the body control module (BCM). The BCM monitors the signal circuit voltage and when the flash to pass switch is activated the switch contacts close the headlamps on and high beam signal circuits to ground.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool headlamp on switch and high beam select switch parameters while operating the flash to pass switch on and off. The readings should change between active and inactive.

  1. Ignition OFF, disconnect the inline harness connector X204.
  2. Test for less than 5 ohms between the ground circuit terminal B10 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify the scan tool headlamp on switch parameter is inactive. If not the specified value, test the signal circuit terminal A10 for a short to ground. If the circuit tests normal, replace the BCM.
  4. Verify the scan tool high beam select switch parameter is inactive. If not the specified value, test the signal circuit terminal A11 for a short to ground. If the circuit tests normal, replace the BCM.
  5. Install a 3A fused jumper wire between the signal circuit terminal A10 and the ground circuit terminal B10. Verify the scan tool headlamp on switch parameter is active. If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  6. Install a 3A fused jumper wire between the signal circuit terminal A11 and the ground circuit terminal B10. Verify the scan tool high beam select switch parameter is active. If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  7. If all circuits test normal, test or replace the turn signal/multifunction switch.

Flash to Pass Switch Test

  1. Ignition OFF, disconnect the inline harness connector X204.
  2. Test for infinite resistance between the signal terminal A10 and the low reference terminal B10. If not the specified value, replace the turn signal/multifunction switch.
  3. Test for infinite resistance between the signal terminal A11 and the low reference terminal B10. If not the specified value, replace the turn signal/multifunction switch.
  4. Test for less than 5 ohms between the signal terminal A10 and the low reference terminal B10 while activating the flash to pass switch. If greater than the specified range, replace the turn signal/multifunction switch.
  5. Test for less than 5 ohms between the signal terminal A11 and the low reference terminal B10 while activating the flash to pass switch. If greater than the specified range, replace the turn signal/multifunction switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Turn Signal Multifunction Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/steering-column-switches/#steering-wheel-steering-column)
  2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The instrument panel cluster (IPC) illuminates the high beam indicator when the BCM detects that the high beams are requested. The IPC receives a class 2 message from the BCM requesting illumination.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for Scan Tool Information

Ignition ON, turn the headlamp dimmer switch to the high beam position and observe the headlamps and the IPC high beam indicator. The high beam headlamps and the high beam indicator should illuminate.

Ignition ON, with a scan tool perform the Display Test for the instrument panel cluster (IPC) and observe the high beam indicator.

  1. If the high beam indicator does not illuminate during the test or remains illuminated at all times, replace the IPC.
  1. If the high beam indicator illuminates during the test, replace the BCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM or IPC replacement, setup, and programming.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When the ignition switch is turned to the RUN position, the radio VF displays turn ON at maximum brightness. When the park lamps are ON, all dimmable incandescent back lighting illuminate at the dimming level indicated by the I/P dimmer switch and all the other back lighting lamps illuminate at full intensity. At the same time all VF displays dim to match the indicated dimming level. The panel dimmer switch potentiometer is an input to the BCM. When the driver selects a dimming setting by moving the I/P dimming switch potentiometer, all dimmable incandescent back lighting lamps are provided with a specific voltage. When the I/P dimmer switch is moved from MIN to MAX, all VF displays, as well as all dimmable incandescent back lighting respond from minimum intensity to maximum brightness in response to the I/P dimmer switch The grounding for all of the incandescent back lighting lamps is provided by G106.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool Dimming Potentiometer parameter while operating the dimmer switch from high to low. The voltage reading should change from high to low as the switch is rotated.

  1. If the reading does not change, refer to Dimmer Switch Circuit Test below.
  1. If the scan tool dimmer control operates normal, refer to Interior Backlighting Circuit Test below.

Dimmer Switch Circuit Test

  1. Ignition OFF, disconnect the headlamp switch connector.
  2. Ignition OFF, verify that a test lamp illuminates between the low reference circuit terminal 3 and battery voltage. If the test lamp does not illuminate, test the low reference circuit for an open/high resistance.
  3. Ignition ON, verify that the scan tool dimming potentiometer parameter displays greater than 4 volts. If the parameter displays less than the specified value, test the switch signal circuit 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 14 and the low reference circuit terminal 3. Verify the scan tool dimming potentiometer parameter displays less than 1 volt. If the parameter displays greater than the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  5. If the 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 affected component ground circuit terminal and battery voltage. HVAC control module X1 terminal 14 Hazard switch terminal B Accessory switch terminal H If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
  3. Connect a test lamp between the affected component backlighting control circuit terminal and ground. HVAC control module X1 terminal 14 Hazard switch terminal A Accessory switch terminal G
  4. Ignition ON and parklamps ON, operate the dimmer switch from high to low. The test lamp should illuminate bright to dim when rotating the dimmer switch. 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.

Dimmer Switch Test

  1. Ignition OFF, disconnect the harness connector at the headlamp switch.
  2. Test for 0.0 to 5.0K ohms between the signal terminal 14 and the low reference terminal 3 while rotating the dimmer switch from high to low. If not the specified value, replace the headlamp switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Headlamp Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  2. «Hazard Warning Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  3. «Accessory Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/gauges-instrument-panels/#instrument-panel-system-displays-gages)
  4. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM, or HVAC module, replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The park, tail, marker, and license lamps are turned ON when the headlamp switch is placed in the PARK or ON position or anytime the headlights are requested. The underhood fuse block supplies battery voltage to both the park lamp relay switch contacts and the park lamp coil circuit. The body control module (BCM) provides a ground or control circuit to the park lamp relay coil circuit. When the park lamps are requested ON, the BCM energizes the park lamp relay. Current flow is from the park lamp relay to the individual park lamp circuit fuses and to their respective park, tail, marker, license and clearance lamps. The front park, marker, tail, and license lamps are grounded at G105. If the driver places the headlight switch in the ON position after the ignition switch has been turned OFF, the park, tail, and license lamps will remain ON until turned OFF or the battery runs dead.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, observe the scan tool BCM Parklamp Switch parameter while cycling the headlamp switch between the Park and Off positions. The parameter should cycle between Active and Inactive. If the parameter does not cycle between the specified values, refer to Headlamp Switch Circuit Test below.
  2. Command the Parking Lamps ON and OFF with a scan tool. Verify the park, license, and tail lamps turn ON and OFF. If any of the lamps do not cycle between the commanded states, refer to Exterior Lamps Circuit Test below.

Headlamp Switch Circuit Test

  1. Ignition OFF, disconnect the harness connector at the headlamp switch.
  2. Ignition OFF, test for less than 5 ohms between the low reference circuit terminal 3 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance.
  3. Ignition ON, verify the scan tool BCM Parklamp Switch parameter is Off. 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 On. 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.

Exterior Lamps Circuit Test

  1. Ignition OFF, disconnect an affected park or license lamp bulb.
  2. Verify that a test lamp illuminates when connected between battery voltage and the listed ground circuit terminal. Park or tail lamp terminal G 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. Park or tail lamp terminal B License lamp terminal A
  4. Turn the park lamp switch on and off and verify that the test lamp turns on an off. If the test lamp does not illuminate test the control circuit for an open/high resistance. If the test lamp remains illuminated test the control circuit for a short to voltage.
  5. If all circuits test normal replace the affected bulb.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Headlamp Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  2. «Park/Turn Signal/Side Marker Lamp Bulb Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  3. «License Lamp Bulb Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  4. «Tail Lamp Bulb Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The STOP fuse in the underhood fuse block supplies battery voltage to the normally open stop lamp switch. When the driver presses the brake pedal, the switch contacts close and battery voltage is supplied to the electronic brake control module (EBCM), powertrain control module (PCM), left and right stop lamps, and the center high mounted stop lamp (CHMSL).

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the stop lamps while pressing and releasing the brake pedal. The stop lamps should turn on and off.

  1. If not refer to the stop lamp circuit test below.

Stop Lamp Circuit Test

  1. Ignition OFF, disconnect the harness connector at the stop lamp switch.
  2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 1 and ground. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the signal circuit terminal 2 for a short to ground.
  3. Connect the harness connector at the stop lamp switch.
  4. Disconnect the harness connector at an affected stop lamp.
  5. Test for less than 5 ohms between the listed ground circuit terminal and ground. Left or right stop lamp terminal G CHMSL terminal B If greater than the specified range, test the ground circuit for an open/high resistance.
  6. Verify that a test lamp does not illuminate between the stop lamp control circuit terminal A and ground. If the test lamp illuminates, test the control circuit for a short to voltage.
  7. Verify that the test lamp illuminates when the brake pedal is pressed. If the test lamp does not illuminate, test the control circuit for an open/high resistance. If the circuit tests normal replace the stop lamp switch.
  8. If all circuits test normal, replace the affected stop lamp.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Tail Lamp Bulb Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  2. «Stop Lamp Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  3. «High Mount Stop Lamp Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The TRN/HAZRD FRT and TRN/HAZRD REAR fuses in the underhood fuse block supplies battery positive voltage to the body control module (BCM). When the turn signal switch is placed in either the left or right position, a signal is sent to the BCM to illuminate the desired turn signal lamps. The BCM has an internal flasher that sends an ON-OFF voltage signal to either the left or right turn signals and their instrument panel cluster (IPC) indicator.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, command the following ON and OFF with a scan tool. The respective turn signal lamp should turn on and off. LF Turn Signal LR Turn Signal RF Turn Signal RR Turn Signal If the turn signal lamp is always on or does not turn on, refer to Turn Signal Lamp Circuit Malfunction below.
  2. Ignition ON, operate the left and right turn signals from the multifunction/turn signal switch and verify the left and right turn signal lamps and indicators operate normal. If the left or right turn signals do not operate, refer to the Turn Signal Switch Circuit Test below.

Turn Signal Lamp Circuit Malfunction

  1. Ignition OFF, disconnect the harness connector at the affected turn signal bulb.
  2. Verify that a test lamp illuminates when connected from battery voltage to the ground circuit terminal G. If the test lamp does not illuminate 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 G.
  4. Ignition ON, operate the right turn signal and verify that the test lamp flashes. 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 bulb.

Turn Signal Switch Circuit Test

  1. Ignition OFF, disconnect the harness connector X204 at the turn signal/multifunction switch.
  2. Test for less than 5 ohms between the ground circuit terminal B9 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify battery voltage is present between the turn signal switch signal circuit terminal B5 and ground. If not the specified value, test the signal circuit terminal B5 for an open/high resistance or short to ground. If the circuit tests normal, replace the BCM.
  4. If all circuits test normal, test or replace the turn signal/multifunction switch.

Turn Signal Switch Test

  1. Ignition OFF, disconnect the harness connector X204 at the turn signal/multifunction switch.
  2. Test for infinite resistance between the signal terminal B5 and the ground terminal B9 with the switch in the neutral position. If not the specified value, replace the turn signal/multifunction switch.
  3. Test for 1k ohm between the signal terminal B5 and the ground terminal B9 with the switch in the right turn position. If not the specified value, replace the turn signal/multifunction switch.
  4. Test for 3.5k ohms between the signal terminal B5 and the ground terminal B9 with the switch in the left turn position. If not the specified value, replace the turn signal/multifunction switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Park/Turn Signal/Side Marker Lamp Bulb Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  2. «Tail Lamp Bulb Replacement»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems)
  3. «Turn Signal Multifunction Switch Replacement»(/chevrolet/colorado/i-2004-2012/remont/steering-column-switches/#steering-wheel-steering-column)
  4. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup, and programming

Stop Lamp Switch Adjustment

  1. Rotate the switch counterclockwise, allowing the retainer to release.
  2. Pull the brake pedal rearward to full stop.
  3. While holding the brake pedal FIRMLY in position rearward, push the switch inward fully until the switch body contacts the brake pedal arm striker plate. At this point the plunger in the switch should be pushed in.
  4. Rotate the switch clockwise until a "click" is heard.
  5. The switch is properly adjusted when there is 7 mm (0.028 in) clearance between the end of the switch barrel and the striker plate on the brake pedal arm.

Removal Procedure

  1. Disconnect the stop lamp switch electrical connectors (1).
  2. Rotate the switch counterclockwise.
  3. Remove the switch from the bracket.
  4. Remove the switch from the vehicle.

Installation Procedure

  1. Position the switch near the bracket.
  2. Ensure the switch key-way is properly indexed to the plastic retainer.
  3. Install and adjust the switch. Refer to «Stop Lamp Switch Adjustment»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems__stop-lamp-switch-adjustment) .
  4. Connect the stop lamp switch electrical connectors (1).
  5. Check the switch for proper operation.
  1. Remove the knee bolster trim panel. Refer to «Driver Knee Bolster Panel Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
  2. Remove the screw retaining the switch to the instrument panel (I/P).
  3. Partially remove the switch from the I/P.
  4. Disconnect the switch electrical connector.
  5. Remove the switch from the vehicle.
  1. Position the switch to the I/P.
  2. Connect the electrical connector to the switch.
  3. Install the switch to the I/P.
  4. Install the screw retaining the switch to the I/P. Tighten: Tighten the screw to 2.5 N.m (22 lb in).
  5. Install the knee bolster trim panel. Refer to «Driver Knee Bolster Panel Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
  1. Open the door.
  2. Remove the screw retaining the door jamb switch (1) to the body.
  3. Remove the door jamb switch (1) from the body.
  4. Disconnect the electrical connector from the switch.
  1. Connect the electrical connector to the door jamb switch (1).
  2. Install the door jamb switch (1) to the body.
  3. Install the screw retaining the door jam switch to the body. Tighten: Tighten the door jamb switch screw to 1.5 N.m (13 lb in).
  4. Close the door.
  1. Remove the instrument panel (I/P) accessory trim plate. Refer to «Instrument Panel Accessory Trim Plate Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
  2. Disconnect the hazard switch electrical connector.
  3. Release the tabs retaining the switch to the trim plate.
  4. Remove the switch (1) from the trim plate.
  1. Position the switch (1) to the trim plate.
  2. Ensure the switch key-way is indexed to the trim plate.
  3. Install the switch to the trim plate ensuring the tabs are fully seated.
  4. Connect the hazard switch electrical connector.
  5. Install the I/P accessory trim plate. Refer to «Instrument Panel Accessory Trim Plate Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
  1. Carefully use a flat-bladed tool, and remove the sensor from the upper portion of the instrument panel (I/P).
  2. Disconnect the electrical connector (2) from the sensor ensuring the connector does NOT fall through the hole in the I/P.
  3. Remove the sensor from the vehicle.
  1. Connect the electrical connector (2) to the sensor.
  2. Align the sensor to the I/P for installation.
  3. Apply downward pressure to the sensor head in order to seat the sensor to the I/P.
  1. Remove the lens from the dome lamp.
  2. Carefully use a flat-bladed tool, and release the tabs (2) retaining to the dome lamp to the headliner.
  3. Lower the dome lamp and disconnect the electrical connector (1).
  4. Remove the dome lamp from the vehicle.
  1. Position the dome lamp to the headliner and connect the electrical connector (1).
  2. Ensure the retaining tabs (2) are in the open position.
  3. Install the dome lamp into the headliner opening and close the retaining tabs (2).
  4. Ensure the dome lamp is secure to the headliner.
  5. Install the lens to the dome lamp.
CAUTIONHalogen bulbs contain gas under pressure. Handling a bulb improperly could cause it to shatter into flying glass fragments. To help avoid personal injury: Turn off the lamp switch and allow the bulb to cool before changing the bulb. Leave the lamp switch OFF until the bulb change is complete. Always wear eye protection when changing a halogen bulb. Handle the bulb only by its base. Avoid touching the glass. Keep dirt and moisture off the bulb. Properly dispose of the used bulb. Keep halogen bulbs out of the reach of children.

Note. Avoid touching the bulb or letting the bulb come in contact with anything damp. Oil from your skin or moisture on the bulb can cause the bulb to explode when the bulb is turned on. If either comes in contact with the bulb, clean the bulb with alcohol or a suitable degreaser and wipe the bulb dry.

  1. Ensure that the headlamp switch is in the OFF position.
  2. Ensure that the ignition switch is in the LOCK position.
  3. Remove the front grille. Refer to «Grille Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#exterior-trim) .
  4. Remove the bolts that retain the headlamp.
  5. Push and rotate the park lamp (1), high beam headlamp (2), low beam headlamp (3), or the DRL, Park and turn signal, and front side marker bulb (4) 1/4 turn counterclockwise in order to remove the bulb, if needed.
  6. Disconnect the electrical connector.
  1. Connect the electrical connector to the bulb.
  2. Push in and rotate the park lamp (1), high beam headlamp (2), low beam headlamp (3), or the DRL, Park and turn signal, and front side marker bulb 1/4 turn clockwise in order to install the bulb.
  3. Install the bolts that retain the headlamp. Tighten: Tighten the bolts to 10 N.m (89 in lb).
  4. Inspect the headlamps for proper operation.
  5. Install the front grille. Refer to «Grille Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#exterior-trim) .
CAUTIONHalogen bulbs contain gas under pressure. Handling a bulb improperly could cause it to shatter into flying glass fragments. To help avoid personal injury: Turn off the lamp switch and allow the bulb to cool before changing the bulb. Leave the lamp switch OFF until the bulb change is complete. Always wear eye protection when changing a halogen bulb. Handle the bulb only by its base. Avoid touching the glass. Keep dirt and moisture off the bulb. Properly dispose of the used bulb. Keep halogen bulbs out of the reach of children.

Note. Avoid touching the bulb or letting the bulb come in contact with anything damp. Oil from your skin or moisture on the bulb can cause the bulb to explode when the bulb is turned on. If either comes in contact with the bulb, clean the bulb with alcohol or a suitable degreaser and wipe the bulb dry.

  1. Ensure that the headlamp switch is in the OFF position.
  2. Ensure that the ignition switch is in the LOCK position.
  3. Remove the front grille. Refer to «Grille Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#exterior-trim) .
  4. Remove the bolts that retain the headlamp.
  5. Push and rotate the high beam headlamp (2), low beam headlamp (3) 1/4 turn counterclockwise in order to remove the bulb, if needed.
  6. Disconnect the electrical connector.
  1. Connect the electrical connector to the bulb.
  2. Push in and rotate the high beam headlamp (2), low beam headlamp (3) 1/4 turn clockwise in order to install the bulb.
  3. Install the bolts that retain the headlamp. Tighten: Tighten the bolts to 10 N.m (89 lb in).
  4. Inspect the headlamps for proper operation.
  5. Install the front grille. Refer to «Grille Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#exterior-trim) .

Screen Method for Headlamp Aiming

The screen method requires an area set up specifically for headlamp aiming.

Scheme 12

Scheme 12: Screen Method for Headlamp Aiming
Scheme 12: Screen Method for Headlamp Aiming

The area should consist of a level surface large enough to allow for a vehicle and an additional 7.62 m (25 ft) as measured from the face of the headlamps to the aiming screen.

Scheme 13

Scheme 13
Scheme 13

The screen should be a wall or other flat surface at least 1.52 m (5 ft) high by 3.66 m (12 ft) wide with a matte white surface well shaded from extraneous light, and 90 degrees to the floor. The screen should be provided with a permanent vertical reference line 0.61 m (2 ft) from the left edge of the screen, 2 laterally adjustable vertical tapes, and one vertically adjustable horizontal tape.

After the aiming screen has been set up and located, paint or tape a reference line on the floor 15.24 m (50 ft) from the vertical reference line on the screen. This line should be perpendicular to the aiming screen and a mark placed at 7.62 m (25 ft) from the screen.

Headlamp Aiming Procedure

  1. Align the left tires of the vehicle with the reference line extending from the screen with the headlamps aligned with the reference line.
  2. Remove any snow, ice or mud from the vehicle.
  3. The vehicle must be fully assembled and all other work stopped while the headlamp aiming is being done.
  4. The vehicle must contain one person or approximately 160 lb (73 kg).
  5. Tires should be properly inflated.
  6. Rock the vehicle to stabilize the suspension.
  7. Measure from the floor to the reference mark on the headlamp lens (2).
  8. At the screen, measure from the floor and place the horizontal tape at the above measured distance.
  9. Turn the low beam headlamps ON.
  10. The graphic shows the vertical (1) adjustment, no horizontal adjustments are required. Adjust the headlamps to the specifications required by state and local authorities.
  11. The beam pattern must be positioned as shown in the graphic.
  12. Adjust one headlamp at a time while blocking the light from the other. The cover must be away from the headlamp. The following list refers to the callouts in the graphic: The low beam centerline reference mark (4). Distance from ground to the low beam bulb centerline reference mark (1). The ground line (2). Horizontal edge of the low beam headlamp pattern (3). The edge of the headlamp pattern (3), must be 5 cm (2 in) below the reference mark (4), with the vehicle 7.62 m (25 ft) away.
  1. Remove the fog lamp bulb and socket. Refer to «Front Fog Lamp Bulb Replacement (Canyon)»(/chevrolet/colorado/i-2004-2012/remont/exterior-lights/#lighting-systems) .
  2. Remove the bolt (1) securing the fog lamp to the fascia.
  3. Remove the fog lamp (2).
  1. Position the fog lamp (2) to the fascia.
  2. Install the fog lamp to fascia bolts (1). Tighten: Tighten the bolts to 2.5 N.m (22 lb in).
  3. Install the fog lamp bulb and socket.
  1. Turn the fog lamp switch to the OFF position.
  2. Disconnect the electrical connector.
  3. Rotate the bulb socket counterclockwise in order to release the socket from the fog lamp housing.
  4. Remove the socket from the fog lamp housing.
  5. Remove the bulb from the socket (2).
  1. Install the bulb to the socket (2).
  2. Index the tabs on the bulb socket to the slots in the fog lamp housing.
  3. Install the socket to the fog lamp housing.
  4. Rotate the socket clockwise until fully seated.

Fog Lamp Aiming (Canyon)

Proper road illumination and safety require the fog lamps to be aimed. The front fog lamp aim should be checked when a new front fog lamp assembly is installed, or if any service repairs have been performed to the vehicle which disturb the front fog lamp mounting or the vehicle ride height.

There are no horizontal adjustments for aiming the front fog lamp assemblies on this vehicle.

Scheme 14

Scheme 14: Fog Lamp Aiming (Canyon)
Scheme 14: Fog Lamp Aiming (Canyon)

The front foglamps can be adjusted by turning the adjustment screw (2) located below the backside of the lamp, next to the electrical connector.

Use the following guidelines in order to adjust the aim

  1. Turn the TORX® adjustment screw clockwise in order to raise the aim.
  2. Turn the TORX® adjustment screw counter-clockwise in order to lower the aim.
  1. To ensure accurate vertical front fog lamp aiming, first perform the following steps to prepare the vehicle. Make sure that all the components are in place on the vehicle, the tires are properly inflated, and there is not any mud or snow clinging to the vehicle. Stop all other operations of work on the vehicle. Make sure the fuel level is 1/2 full or more. Jounce the vehicle to settle the suspension. Place the vehicle on a level surface 7.6 m (25 ft) from the target screen. Measure the distance from the floor to the center of the fog lamp (5). Using this measurement, mark the horizontal centerline of the fog lamp (1) on the target screen directly in front of the vehicle. Start the vehicle in order to level the suspension.
  2. Turn the front fog lamps ON.
  3. Access the fog lamp vertical adjuster.
  4. Adjust the fog lamp up or down until the top edge of the high intensity zone on the screen is 102 mm (4 in) below (2) the horizontal centerline (1).
  5. Turn OFF the front fog lamps.
CAUTIONHalogen bulbs contain gas under pressure. Handling a bulb improperly could cause it to shatter into flying glass fragments. To help avoid personal injury: Turn off the lamp switch and allow the bulb to cool before changing the bulb. Leave the lamp switch OFF until the bulb change is complete. Always wear eye protection when changing a halogen bulb. Handle the bulb only by its base. Avoid touching the glass. Keep dirt and moisture off the bulb. Properly dispose of the used bulb. Keep halogen bulbs out of the reach of children.

Note. Avoid touching the bulb or letting the bulb come in contact with anything damp. Oil from your skin or moisture on the bulb can cause the bulb to explode when the bulb is turned on. If either comes in contact with the bulb, clean the bulb with alcohol or a suitable degreaser and wipe the bulb dry.

  1. Ensure that the headlamp switch is in the OFF position.
  2. Ensure that the ignition switch is in the LOCK position.
  3. Open the hood.
  4. Release the locking tab (1) on the park, turn, daytime running lamp assembly by using a flat-bladed tool and pushing the tab on the lamp outward toward the fender.
  5. Rotate the outward edge of the lamp assembly forward.
  6. Release the park/turn signal lamp socket (2) by rotating the socket a quarter turn counter-clockwise.
  7. Remove the park, turn signal lamp bulb (3).
  8. Repeat steps 6 and 7 for the daytime running lamp socket (4) and bulb (5).
  1. Secure the bulbs (3,5) into the bulb sockets (2,4) and to the lamp assembly.
  2. Insert the inside edge of the lamp tabs to the grille support.
  3. Rotate the lamp assembly into the fender bracket.
  4. Push on the outboard edge of the lamp until an audible click is heard, when the lamp assembly is secure to the fender.
  5. Inspect the lamps for proper operation.
  1. Remove the screws that retain the high mount stop lamp.
  2. Remove the high mounted stop lamp from the vehicle.
  3. Twist the lamp sockets counterclockwise in order to remove.
  4. Remove the bulbs from the sockets.
  1. Install the bulbs into the lamp sockets.
  2. Install the lamp sockets into the high mounted stop lamp and twist clockwise to secure.
  3. Install the high mount stop lamp to the vehicle.
  4. Install the screws that retain the high mounted stop lamp to the vehicle. Tighten: Tighten the screws to 2.5 N.m (22 lb in).
  1. Remove the screws that retain the center high-mounted stop lamp (CHMSL) lens to the vehicle.
  2. Remove the CHMSL from the vehicle.
  3. Twist the lamp sockets (1) counterclockwise to remove.
  4. Remove the bulbs from the sockets.
  1. Install the CHMSL bulbs (1).
  2. Install the CHMSL assembly to the vehicle. Ensure that the CHMSL gasket is seated properly.
  3. Install the screws that retain the center high-mounted stop lamp (CHMSL) lens to the vehicle. Tighten: Tighten the screws to 2.5 N.m (22 lb in).
  1. Open the tailgate.
  2. Remove the screws (1) from the tail lamp assembly.
  3. Remove the lamp assembly.
  4. Remove the tail lamp and backup lamp sockets, depressing the locking tab and rotating counterclockwise.
  5. Remove the bulbs from the backup lamp sockets.
  1. Install the bulbs to the backup lamp sockets.
  2. Install the backup lamp rotating clockwise until the locking tab is fully seated.
  3. Press the tail lamp to the rear body panel until fully seated.
  4. Install the tail lamp screws (1) to the tail lamp. Tighten: Tighten the tail lamp screws (1) to 3 N.m (26 lb in).
  5. Close the tailgate.
  1. Ensure the headlamp switch is in the OFF position.
  2. Disconnect the electrical connector (2) from the license lamp assembly (1).
  3. Remove the nut (3) retaining the license lamp to the bumper.
  4. Remove the license lamp assembly from the bumper.
  5. Twist the lamp socket counterclockwise to remove.
  6. Remove the bulb.
  1. Install the bulb to the lamp socket.
  2. Twist the lamp socket clockwise to install.
  3. Install the lamp assembly (1) into the bumper.
  4. Install the license lamp nut (3). Tighten: Tighten the nut to 2.5 N.m (22 lb in).
  5. Install the electrical connector (2).
  6. Inspect the lamp operation.
  1. Open the tailgate.
  2. Remove the screws (1) from the tail lamp assembly.
  3. Remove the lamp assembly.
  4. Remove the tail lamp and backup lamp sockets, depressing the locking tab and rotating counterclockwise.
  1. Install the tail lamp and/or backup lamp sockets to the tail lamp, rotating clockwise until the locking tab is fully seated.
  2. Press the tail lamp to the rear body panel until fully seated.
  3. Install the tail lamp screws (1) to the tail lamp. Tighten: Tighten the tail lamp screws (1) to 3 N.m (26 lb in).
  4. Close the tailgate.
  1. Open the tailgate.
  2. Remove the screws (1) from the tail lamp assembly.
  3. Remove the lamp assembly.
  4. Remove the tail lamp sockets by depressing the locking tab and rotating counterclockwise.
  5. Remove the bulbs from the tail lamp and/or side marker lamp sockets.
  1. Install the bulbs to the tail lamp, and/or side marker lamp sockets.
  2. Install the tail lamp sockets to the tail lamp, rotating clockwise until the locking tab is fully seated.
  3. Press the tail lamp to the rear body panel until fully seated.
  4. Install the tail lamp screws (1) to the tail lamp. Tighten: Tighten the tail lamp screws (1) to 3 N.m (26 lb in).
  5. Close the tailgate.

Exterior Lamps

The exterior lighting system consists of the following lamps

  1. The headlamps
  2. The daytime running lamps (DRL)
  3. The front fog lamps
  4. The park, tail, and marker lamps
  5. The turn signal lamps
  6. The stop lamps
  7. The backup lamps

The cargo lamp on the vehicle exterior is supplied voltage by the courtesy lamp supply voltage circuit and will only operate while the courtesy lamps are illuminated. This circuit is diagnosed as part of the interior courtesy lamp lighting system. Refer to Interior Lighting Systems Description and Operation .

Headlamps

Major components of this system are the body control module (BCM), headlamp relay, beam select relay, ambient light sensor, headlamp and panel dimmer switch, turn signal/multifunction switch, park brake switch, and the low and high beam headlamps.

The headlamps may be turned ON in 3 different ways. First, when the driver places the headlamp switch in the ON position, normal operation occurs. Second, when the headlamp switch is placed in the AUTO position, automatic lamp control (ALC) operation occurs. During ALC control, the headlamps will be OFF in daylight conditions or in low/high beam operation in low light conditions. Third is in wiper activated headlamp (WAH) mode. Only when the wiper system is activated while the vehicle is in gear, the wiper blades have completed at least 3 cycles, and then a 35 second time period expires, will the BCM switch from daytime running lamps (DRL) mode to headlamp mode during daylight conditions. When the gearshift lever is placed in the PARK or NEUTRAL position or if the wipers are turned OFF, normal manual or ALC operation will resume after approximately 60 seconds.

The headlamp relay receives battery positive voltage directly from the battery. The BCM supplies a ground signal to the headlamp relay for normal headlight operation. The BCM also supplies voltage to the beam select relay coil for high beam headlight operation. When the driver places the headlamp switch in the ON position and the dimmer switch is in the low beam position, the headlamp relay supplies current flow through the left and right low beam headlamp fuses to both low and high beam headlamps. Both low beam headlights are grounded through the beam select relay. When activated, the dimmer switch sends a ground signal to the BCM in the high beam position and a momentary ground signal in the flash-to-pass (FTP) position from G106. The BCM then energizes the beam select relay which switches the headlamp grounds from the low beam headlight bulbs to the high beam headlight bulbs illuminating the high beam headlights. With the headlights in the low beam position, the high beams may be momentarily turned ON or flashed by activating the FTP portion of the switch.

The instrument panel cluster (IPC) illuminates the high beam indicator when the BCM detects that the high beams are requested. The IPC receives a class 2 message from the BCM requesting illumination.

The Headlamps On at Exit and Perimeter Lighting modes can be adjusted using the steering wheel controls to select the desired function as displayed in the driver information center (DIC). The Headlamps On at Exit selection will allow the driver to customize the period of time that the headlamps remain illuminated upon exiting the vehicle. This period can be adjusted from 0-180 seconds. The Perimeter Lighting feature allows the driver to select if they desire the headlamps and backup lamps to illuminate when the door UNLOCK button on the key fob is activated. This feature can be turned ON or OFF by using the DIC steering wheel control buttons.

Daytime Running Lamps (DRL)

The ambient light sensor is a light sensitive transistor that varies its voltage signal to the body control module (BCM) in response to changes to the outside (ambient) light level. When the BCM receives this signal, it will either turn ON the daytime running lamps (DRL) or the headlamps for auto headlamp operation. Any function or condition that turns ON the headlights will cancel the DRL operation. With the headlight switch in the AUTO position, the headlights will either be turned ON or OFF, after an approximate 8 second delay depending on whether daylight or low light conditions are sensed. When the ambient light sensor signals the BCM for DRL operation in daylight conditions, the BCM illuminates the low beam headlamps at a reduced intensity utilizing the DRL relay. The DRL will operate when the ignition switch is in the RUN position, the headlamp and panel dimmer switch is in the AUTO position, the gear selector is not in the PARK position, and the parking brake is released. When these conditions have been met and the ambient light sensor indicates daytime conditions, the DRL will illuminate.

DRL operation can be temporarily disabled by momentarily placing the headlamp switch in the OFF position. This will cancel DRL operation until the switch is momentarily placed in the OFF position again or until the next ignition key cycle occurs. Canadian requirements prohibit disabling DRL operation therefore the Canadian export vehicles are not equipped with the DRL defeat feature.

Fog Lamps

With both the ignition switch in the RUN position and the park lamps or low beam head lamps ON, the fog lights will illuminate when the driver presses the fog lamp switch. The FOG LP fuse in the underhood fuse block supplies battery positive voltage to the fog lamp relay. With the headlamp switch is in either the park or headlamp position and the fog lamp switch is pressed, the body control module (BCM) will energize the fog lamp relay control circuit. The current flow is from the fog lamp relay to both front fog lamps and to ground G106. The state of the fog lamps, either ON or OFF, will remain the same until the fog lamp switch is pressed again, or the ignition switch is cycled OFF and ON. Fog lamp operation will be cancelled whenever the park lamps are turned OFF or the high beam headlights have been selected.

Park, Tail, Marker, License, and Clearance Lamps

The park, tail, marker, and license lamps are turned ON when the headlamp switch is placed in the PARK or ON position or anytime the headlights are requested. The underhood fuse block supplies battery positive voltage to both the park lamp relay switch contacts and the park lamp coil circuit. The body control module (BCM) provides a ground or control circuit to the park lamp relay coil circuit. When the park lamps are requested ON, the BCM energizes the park lamp relay. Current flow is from the park lamp relay to the individual park lamp circuit fuses and to their respective park, tail, marker, and license lamps. The front park, marker, tail, and license lamps are grounded at G105. If the driver places the headlight switch in the ON position after the ignition switch has been turned OFF, the park, tail, marker, and license lamps will remain ON until turned OFF or the battery runs dead.

Turn Signal Lamps

The FRT TRN/HAZ/CRTSY/MIRR/CARGO and REAR TURN/HAZ fuses in the underhood fuse block supplies battery positive voltage to the body control module (BCM). When the turn signal switch is placed in either the left or right position, a signal is sent to the BCM to illuminate the desired turn signal lamps. The BCM has an internal flasher that sends an ON-OFF voltage signal to either the left or right turn signals and their instrument panel cluster (IPC) indicator. When the hazard switch is pressed, a separate ground signal is sent to the BCM to activate and flash all turn signal lamps including both IPC turn indicators. The front and rear turn signals are grounded at G105.

The IPC illuminates the TURN SIGNAL ON indicator in the driver information center (DIC) when the IPC determines that the turn signal is active for more than 1.2 km (0.75 mi). The BCM sends a class 2 message to the radio in order to activate the audible warning.

Stop Lamps

The STOP fuse in the underhood fuse block supplies battery positive voltage to the normally open stop lamp switch. When the driver presses the brake pedal, the switch contacts close and battery positive voltage is supplied to the stop lamps and center high mounted stop lamp (CHMSL) which are grounded at G105.

Backup Lamps

The BACKUP fuse in the underhood fuse block supplies battery positive voltage to the normally open park/neutral position (PNP) switch of a vehicle equipped with an automatic transmission or the backup lamp switch if equipped with a manual transmission. When the driver places the gear selector lever is in the REVERSE position, the switch closes and the current flow is from the switch to the backup lamps. The backup lamps are grounded at G105.

Interior Lamps

The interior lighting consists of the following 2 groups. This first group includes lamps that illuminate the interior and may not be dimmed.

  1. The cargo lamp
  2. The dome lamp
  3. The footwell lamps
  4. The reading lamps

Courtesy Lamps

The courtesy lamps include the reading lamps, footwell lamps, cargo lamp, and dome lamps. The cargo lamp, footwell lamps, and dome lamp may be manually turned ON or OFF by placing the interior lamp switch in the ON or OFF position. When the driver places the dome lamp defeat switch in the OFF position, these courtesy lamps will be disabled. If a door is opened, the courtesy lamps, except the cargo lamp unless activated, will illuminate. After all the doors have been closed, the courtesy lamps will remain illuminated approximately 15 seconds after the last door closes. The courtesy lamps will also turn ON prior to any door being opened and will remain illuminated approximately 40 seconds when the driver removes the ignition key. The body control module (BCM) will immediately turn OFF the courtesy lamps if a door lock command is received with all of the doors closed, or if the ignition switch is turned to either the ON or RUN position. Individual power and ground circuits to each lamp are supplied by the BCM except for the cargo lamp ground which is grounded at G105.

The reading lamps can be activated individually by the switches integrated within the inside rearview mirror. Voltage is supplied by the BCM through the dome lamp circuit with the lamps being grounded at G105 and G300.

The cargo lamp on the vehicle exterior is supplied voltage by a dedicated courtesy lamp supply voltage circuit. Cargo lamp operation can controlled by a push-button switch on the instrument panel (I/P) that sends a momentary ground signal to the BCM. The BCM will then illuminate the cargo lamp only while the courtesy lamps are illuminated.

Keyless Entry Interior Illumination

When the driver uses the door key in order to unlock the doors, the body control module (BCM) receives a door unlock signal. The BCM must have inputs that indicate that the ignition switch is OFF, the courtesy lamp switch is OFF, and all the doors are closed. The BCM will then illuminate the interior lamps. The courtesy lamps will remain illuminated for approximately 15 seconds after the door is closed. If the door locks are activated to the LOCK position, or if the ignition switch is turned to either the RUN or CRANK position, the courtesy lamps will turn OFF immediately.

When the driver uses the remote function actuator transmitter to unlock the doors or presses the panic button, the BCM will keep the courtesy lamps ON for approximately 15 seconds. If the door locks are activated to the UNLOCK or LOCK position or if the ignition switch is turned to either the RUN or CRANK position, the courtesy lamps will turn OFF immediately. The BCM will also keep the courtesy lamps ON for approximately 40 seconds after an alarm event is completed.

Battery Rundown Protection/Inadvertent Power

The body control module (BCM) inadvertent power courtesy lamps supply voltage circuit provides battery positive voltage to all of the interior courtesy lamps. In the event that any of these lamps were to remain illuminated for a period of more than 20 minutes with the ignition switch in the OFF position, the BCM will deactivate the inadvertent power courtesy lamps supply voltage circuit to prevent a total battery discharge condition. Only when the ignition switch is cycled back to the RUN position will the BCM reset the internal timer and reactivate the inadvertent power courtesy lamps supply voltage circuit.

The BCM also utilizes the inadvertent power courtesy lamps supply voltage circuit as a courtesy lamp request signal circuit when none of the lamps in the circuit are illuminated. When a reading lamp switch is activated, the BCM receives the request for lamp illumination and switches to supplying voltage to the inadvertent power courtesy lamps supply voltage circuit.

Interior Switch and Control Illumination

The second group includes lamps which illuminate the interior switches, controls, and displays that may or may not be dimmed. This group may use a combination of LED, incandescent lamps, and vacuum fluorescent (VF) displays.

The first list of components are supplied voltage through the FRT PARK LAMP fuse and the REAR PARK LAMP #2 fuse and cannot be dimmed. These lamps will be illuminated at full intensity whenever the park lamps are ON.

  1. Door lock and window switches
  2. Instrument panel (I/P) switch assembly
  3. Mirror switch

This second list of components are supplied voltage through the body control module (BCM) or controlled via a class 2 signal from the BCM and can be dimmed.

  1. Hazard switch
  2. Headlamp and panel dimmer switch
  3. HVAC control head assembly
  4. Instrument panel cluster (IPC)
  5. Traction control switch
  6. Transfer case control switch
  7. Radio

When the ignition switch is turned to the RUN position, the radio VF displays turn ON at maximum brightness. When the park lamps are ON, all dimmable incandescent back lighting illuminate at the dimming level indicated by the I/P dimmer switch and all the other back lighting lamps illuminate at full intensity. At the same time all VF displays dim to match the indicated dimming level. The panel dimmer switch potentiometer is an input to the BCM. When the driver selects a dimming setting by moving the I/P dimming switch potentiometer, all dimmable incandescent back lighting lamps are provided with a specific voltage. When the I/P dimmer switch is moved from MIN to MAX, all VF displays, as well as all dimmable incandescent back lighting respond from minimum intensity to maximum brightness in response to the I/P dimmer switch The grounding for all of the incandescent back lighting lamps is provided by G106.