Lighting System: Diagnosis Chevrolet Sonic I

Diagnostic Code Index

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

Diagnostic Fault Information

Conditions for Running the DTC

Battery voltage must be between 9-16 V.

Conditions for Setting the DTC

The BCM detects a short to ground in the reading lamp control circuit.

Actions Taken When the DTC Sets

The BCM will disable the circuit and the reading lamp will be inoperative.

Conditions for Clearing the DTC

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

Circuit/System Testing

1. Ignition OFF, exterior lamps OFF, disconnect the harness connectors at the E37F dome/reading lamps-front and E37B dome/reading lamps-2nd row.
2. Connect a test lamp between the appropriate control circuit terminal listed below and ground. E37F dome/reading lamps - front terminal 1 with C95 E37F dome/reading lamps - front terminal 4 with C90/C91 E37B dome/reading lamps - 2nd row terminal 4 with C90/C95
3. Verify the test lamp turns ON and OFF when commanding the Inadvertent Load ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X7 harness connector at the K9 body control module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If the test lamp is always ON Ignition OFF, disconnect the X7 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 body control module. If the test lamp turns ON and OFF
4. Test or replace the appropriate E37 dome/reading lamps.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

1. Battery voltage must be between 9-16 V.
2. Front fog lamps ON.

DTC B2530 01

The BCM detects a short to voltage in the front fog lamp relay control circuit for 5 seconds or greater.

DTC B2530 02

The BCM detects a short to ground in the front fog lamp relay control circuit.

DTC B2530 04

The BCM detects an open in the front fog lamp relay control circuit.

DTC B2530 01 and B2530 04

The front fog lamps will not operate when the park lamps are ON and the front fog lamp switch is active.

DTC B2530 02

The front fog lamps always ON.

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

1. Ignition OFF, disconnect the X5 harness connector at the K9 Body Control Module, ignition ON.
2. Verify a test lamp illuminates between the control circuit terminal 13 and ground. If the test lamp does not illuminate Ignition OFF, disconnect the X2 harness connector at the X50A Fuse Block - Underhood. Test for infinite resistance between the control circuit terminal and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the X50A Fuse Block - Underhood. If the test lamp illuminates
3. Ignition OFF, connect a 3 A fused jumper between the control circuit terminal 13 and ground.
4. Remove the front fog lamp fuse at the X50A Fuse Block - Underhood, ignition ON.
5. Verify a test lamp illuminates between the front fog lamp fuse B+ switch control terminal and ground. If the test lamp does not illuminate Ignition OFF, disconnect the X2 harness connector at the X50A Fuse Block - Underhood, ignition ON. Test for less than 1 V between the control circuit terminal 13 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the X50A Fuse Block - Underhood. If the test lamp illuminates
6. Test or replace the K9 Body Control Module.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

1. Battery voltage must be between 9-16 V.
2. Engine RUNNING.
3. Transmission placed in REVERSE gear.

DTC B2545 01

The BCM detects a short to voltage in the backup lamps control circuit.

DTC B2545 02

The BCM detects a short to ground in the backup lamps control circuit.

DTC B2545 04

The BCM detects an open/high resistance in the backup lamps control circuit.

DTC B2545 02 and B2545 04

The backup lamps will not operate.

DTC B2545 01

The backup lamps are always ON.

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

1. Ignition OFF, disconnect the X5 harness connector at the K9 Body Control Module, ignition ON.
2. Verify a test lamp illuminates between the B+ circuit terminal 4 and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF. Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF. Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If the test lamp illuminates
3. Ignition OFF, connect the X5 harness connector at the K9 Body Control Module.
4. Ignition OFF, exterior lamps OFF, trunk latch latched, remove the appropriate E5 Backup Lamp bulb at the appropriate E42 Tail Lamp Assembly.
5. Test for less than 5 ohms between the ground circuit at the socket terminal and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
6. Connect a test lamp between the control circuit at the socket terminal and ground, ignition ON.
7. Verify the test lamp turns ON and OFF when commanding the Backup Lamps ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
8. Test or replace the appropriate E5 Backup Lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

1. Battery voltage must be between 9-16 V.
2. Rear compartment OPEN.

The BCM detects a short to ground on the rear compartment courtesy lamp control circuit.

The rear compartment lamp is inoperative.

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

1. Ignition OFF, exterior lamps OFF, trunk latch latched, disconnect the harness connector at the E8S Rear Compartment Courtesy Lamp.
2. Test for less than 5 ohms between the ground circuit terminal 2 and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit terminal 1 and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Trunk Lamp ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the E8S Rear Compartment Courtesy Lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

1. Battery voltage must be between 9-16 V.
2. Rear compartment OPEN.

The BCM detects a short to ground on the rear compartment courtesy lamp control circuit.

The rear compartment lamp is inoperative.

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

1. Ignition OFF, exterior lamps OFF, trunk latch latched, disconnect the harness connector at the E8S Rear Compartment Courtesy Lamp.
2. Test for less than 5 ohms between the ground circuit terminal 2 and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit terminal 1 and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Trunk Lamp ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the E8S Rear Compartment Courtesy Lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

1. Battery voltage must be between 9-16 V.
2. Low beam headlamps ON.

DTC B2575 01 and B2575 04

The BCM detects a short to voltage or an open/high resistance in the left low beam headlamp control circuit.

DTC B2575 02

The BCM detects a short to ground in the left low beam headlamp control circuit.

DTC B2699 01 and B2699 04

The BCM detects a short to voltage or an open/high resistance in the right low beam headlamp control circuit.

DTC B2699 02

The BCM detects a short to ground in the right low beam headlamp control circuit.

1. When DTC B2575 sets, the left low beam headlamp will be inoperative.
2. When DTC B2699 sets, the right low beam headlamp will be inoperative.

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.

DTC B2575

1. Ignition OFF, exterior lamps OFF, disconnect the harness connector at the E13L Headlamp - Left.
2. Test for less than 5 ohms between the ground circuit terminal D and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit terminal A and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Left Low Beam/Daytime Running Lamp ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the E4G Headlamp - Left Low Beam.

DTC B2699

1. Ignition OFF, exterior lamps OFF, disconnect the harness connector at the E13R Headlamp - Right.
2. Test for less than 5 ohms between the ground circuit terminal D and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit terminal A and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Right Low Beam/Daytime Running Lamp ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module If the test lamp is always ON Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module If the test lamp turns ON and OFF
5. Test or replace the E4H Headlamp - Right Low Beam.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

Battery voltage must be between 9-16 V.

1. The BCM detects an open/high resistance in the headlamp switch park lamps ON signal circuit.
2. The BCM detects a short to ground in the headlamp switch headlamps ON signal circuit.
3. The BCM detects a short to ground in the headlamp switch headlamps OFF signal circuit.

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

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

1. Ignition OFF, all doors closed, all accessories OFF, disconnect the harness connector at the S30 Headlamp Switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 15 ohms between the ground circuit terminal 6 and ground. If 15 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 15 ohms
3. Ignition ON.
4. Verify the scan tool Automatic Headlamps Disable Switch parameter is Inactive. If not Inactive Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module. Test for infinite resistance between the signal circuit terminal 5 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If Inactive
5. Install a 3 A fused jumper wire between the signal circuit terminal 5 and the ground circuit terminal 6.
6. Verify the scan tool Automatic Headlamps Disable Switch parameter is Active. If not Active Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal 5 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If Active
7. Verify the scan tool Park Lamps Switch parameter is Inactive. If not Inactive Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module. Test for infinite resistance between the signal circuit terminal 3 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If Inactive
8. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the ground circuit terminal 6.
9. Verify the scan tool Park Lamps Switch parameter is Active. If not Active Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal 3 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If Active
10. Verify the scan tool Headlamps On Switch parameter is Inactive. If not Inactive Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module. Test for infinite resistance between the signal circuit terminal 4 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If Inactive
11. Install a 3 A fused jumper wire between the signal circuit terminal 4 and the ground circuit terminal 6.
12. Verify the scan tool Headlamps On Switch parameter is Active. If not Active Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal 4 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If Active
13. Test or replace the S30 Headlamp Switch.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

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

DTC B257B 03

1. The BCM detects a short to ground or an open/high resistance in the instrument panel dimmer switch B+ circuit.
2. The BCM detects a short to ground or an open/high resistance in the instrument panel dimmer switch signal circuit.

DTC B257B 07

The BCM detects a short to voltage in the instrument panel dimmer switch signal circuit.

The BCM will not dim any interior backlighting. All interior backlighting will default to the level selected prior to the fault being present.

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

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S30 Headlamp Switch, ignition ON.
2. Test for B+ between the B+ circuit terminal 1 and ground. If less than B+ Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module. Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If B+
3. Verify a test lamp does not illuminate between the B+ circuit terminal 1 and the signal circuit terminal 12. If the test lamp illuminates Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If the test lamp does not illuminate
4. Test for B+ between the B+ circuit terminal 1 and the signal circuit terminal 12. If less than B+ Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal 12 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If B+
5. Test or replace the S30 Headlamp Switch.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

1. Battery voltage must be between 9-16 V.
2. High beam headlamps ON.

DTC B2580 01

The BCM detects a short to voltage in the headlamp high beam relay control circuit.

DTC B2580 02

The BCM detects a short to ground in the headlamp high beam relay control circuit.

DTC B2580 04

The BCM detects an open in the headlamp high beam relay control circuit.

The high beam headlamps and flash to pass will not operate.

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

1. Ignition OFF, remove the KR48 Headlamp High Beam Relay.
2. Connect a test lamp between the control circuit terminal 86 and B+, ignition ON.
3. Verify the test lamp turns ON and OFF when commanding the High Beams ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X5 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Ignition OFF. Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X5 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit terminal and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If the test lamp turns ON and OFF
4. Test or replace the KR48 Headlamp High Beam Relay.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

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

DTC B2585 01 and B2585 04

The BCM detects a short to voltage or an open/high resistance in the left front park lamps control circuit.

DTC B2585 02

The BCM detects a short to ground in the left front park lamps control circuit.

DTC B3867 01 and B3867 04

The BCM detects a short to voltage or an open/high resistance in the right front park lamps control circuit.

DTC B3867 02

The BCM detects a short to ground in the right front park lamps control circuit.

DTC B2585 01

The left park lamps are always ON.

DTC B2585 02 and B2585 04

The left park lamps are always OFF.

DTC B3867 01

The right park lamps are always ON.

DTC B3867 02 and B3867 04

The right park lamps are always OFF.

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.

DTC B2585

1. Ignition OFF, exterior lamps OFF, trunk latch latched, disconnect the harness connector at the appropriate left front park lamp or left rear side marker lamp.
2. Test for less than 5 ohms between the appropriate ground circuit terminal listed below and ground. E4N park/turn signal lamp - left terminal C E2LR side marker lamp - left rear socket terminal If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the appropriate control circuit terminal listed below and ground, ignition ON. E4N park/turn signal lamp - left terminal A E2LR side marker lamp - left rear socket terminal
4. Verify the test lamp turns ON and OFF when commanding the Left Park Lamps ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X4 harness connector at the K9 body control module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If the test lamp is always ON Ignition OFF, disconnect the X4 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 body control module. If the test lamp turns ON and OFF
5. Test or replace the appropriate left park/marker lamp.

DTC B3867

1. Ignition OFF, exterior lamps OFF, trunk latch latched, disconnect the harness connector at the appropriate right front park lamp or right rear side marker lamp.
2. Test for less than 5 ohms between the appropriate ground circuit terminal listed below and ground. E4P park/turn signal lamp - right terminal C E2RR side marker lamp - right rear socket terminal If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the appropriate control circuit terminal listed below and ground, ignition ON. E4P park/turn signal lamp - right terminal A E2RR side marker lamp - right rear socket terminal
4. Verify the test lamp turns ON and OFF when commanding the Right Park Lamps ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X4 harness connector at the K9 body control module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If the test lamp is always ON Ignition OFF, disconnect the X4 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 body control module. If the test lamp turns ON and OFF
5. Test or replace the appropriate right park/marker lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

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

DTC B2610 01

The BCM detects a short to battery in the LED backlight dimming control circuit terminal 8 X2.

DTC B2610 02

The BCM detects a short to ground in the LED backlight dimming control circuit terminal 8 X2.

DTC B2610 04

The BCM detects an open/high resistance in the LED backlight dimming control circuit terminal 8 X2.

The BCM will disable the LED backlight dimming control circuits.

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

1. Ignition OFF, all doors closed, all accessories OFF, disconnect the harness connector at the component with inoperative backlighting. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 15 ohms between the appropriate ground circuit terminal listed below and ground. S13D Door Lock Switch - Driver terminal 1 S30 Headlamp Switch - terminal 6 S48E Multifunction Switch - Center Console terminal 9 S70R Steering Wheel Controls Switch - Right terminal 5 S70L Steering Wheel Controls Switch - Left terminal 7 If 15 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 15 ohms
3. Connect a test lamp between the appropriate control circuit terminal listed below and ground. K33 HVAC Control Module - terminal 8 S13D Door Lock Switch - Driver terminal 2 S30 Headlamp Switch - terminal 7 S48E Multifunction Switch - Center Console terminal 10 S70R Steering Wheel Controls Switch - Right terminal 4 S70L Steering Wheel Controls Switch - Left terminal 6
4. Verify the test lamp turns ON and OFF when commanding the LED Backlight Dimming ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the component with inoperative backlighting.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

Battery voltage must be between 9-16 V.

The BCM detects a short to ground in the dome lamps control circuit.

The BCM will disable the dome lamps control circuit.

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

1. Ignition OFF, all doors closed, all accessories OFF, disconnect the harness connector at the E37F Dome/Reading Lamps - Front and E37B Dome/Reading Lamps - 2nd row. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the appropriate ground circuit terminal listed below and ground. E37F Dome/Reading Lamps - Front terminal 2 with C90/C91 E37F Dome/Reading Lamps - Front terminal 6 with C95 E37B Dome/Reading Lamps - 2nd row terminal 2 with C90/C95 If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
3. Connect a test lamp between the appropriate control circuit terminal listed below and ground. E37F Dome/Reading Lamps - Front terminal 3 with C90/C91 E37F Dome/Reading Lamps - Front terminal 2 with C95 E37B Dome/Reading Lamps - 2nd row terminal 3 with C90/C95
4. Verify the test lamp turns ON and OFF when commanding the Courtesy Lamps ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the inoperative E37 Dome/Reading Lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

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

The BCM detects a short to ground in the LED backlight dimming control circuit terminal 5 X1.

The LED backlight dimming control circuit driver is shut down.

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

1. Ignition OFF, disconnect the X2 harness connector at the K33 HVAC Control Module.
2. Connect a test lamp between the control circuit terminal 9 and ground.
3. Verify the test lamp turns ON and OFF when commanding the LED Backlight Dimming ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
4. Test or replace the K33 HVAC Control Module.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

Battery voltage must be between 9-16 V.

DTC B2645 03

The BCM detects a short to ground in the ambient light sensor signal circuit.

DTC B2645 07

1. The BCM detects a short to voltage or an open/high resistance in the ambient light sensor signal circuit.
2. The BCM detects an open/high resistance in the ambient light sensor ground circuit.

1. Automatic headlamp system and daytime running lamps are inoperative.
2. The BCM defaults to low light status and commands the low beam headlamps ON.

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

1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, open and close drivers door, disconnect the harness connector at the B10 Ambient Light Sensor. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 15 ohms between the ground circuit terminal 6 and ground. If 15 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 15 ohms
3. Ignition ON.
4. Verify the scan tool Ambient Light Sensor parameter is greater than 4.65 V. If 4.65 V or less Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module. Test for infinite resistance between the signal circuit terminal 5 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If greater than 4.65 V
5. Install a 3 A fused jumper wire between the signal circuit terminal 5 and the ground circuit terminal 6.
6. Verify the scan tool Ambient Light Sensor parameter is less than 0.196 V. If 0.196 V or greater Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal 5 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If less than 0.196 V
7. Test or replace the B10 Ambient Light Sensor.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

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

The BCM detects a short to ground in the transmission shift lever position indicator backlighting control circuit.

The BCM will disable the transmission shift lever position indicator backlighting control circuit.

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

1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the P2 Transmission Shift Lever Position Indicator. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 15 ohms between the ground circuit terminal 2 and ground. If 15 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 15 ohms
3. Connect a test lamp between the control circuit terminal 1 and ground.
4. Verify the test lamp turns ON and OFF while turning the headlamp switch ON and OFF. If the test lamp is always OFF Ignition OFF, disconnect the X6 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X6 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the P2 Transmission Shift Lever Position Indicator.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

1. Battery voltage must be between 9-16 V.
2. Hazard lamps ON.

The hazard warning switch input is Active for longer than 60 seconds.

The hazard lamps are inoperative.

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

1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the S26 Hazard Warning Switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 5 ohms between the ground circuit terminal 3 and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Ignition ON.
4. Verify the scan tool Hazard Lamps Switch parameter is Inactive. If not Inactive Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module. Test for infinite resistance between the signal circuit terminal 1 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If Inactive
5. Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground.
6. Verify the scan tool Hazard Lamps Switch parameter is Active. If not Active Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal 1 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If Active
7. Test or replace the S26 Hazard Warning Switch.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

Battery voltage must be between 9-16 V.

The BCM detects a short to ground in the turn signal/multifunction switch high beam signal circuit.

The high beam headlamps will not operate.

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

1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the S78 Turn Signal/Multifunction Switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 15 ohms between the ground circuit terminal 3 and ground. If 15 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 15 ohms
3. Ignition ON.
4. Verify the scan tool High Beam Select Switch parameter is Inactive. If not Inactive Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module. Test for infinite resistance between the signal circuit terminal 2 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If Inactive
5. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the ground circuit terminal 3.
6. Verify the scan tool High Beam Select Switch parameter is Active. If not Active Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal 2 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If Active
7. Test or replace the S78 Turn Signal/Multifunction Switch.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

Battery voltage must be between 9-16 V.

The BCM detects a short to ground in the turn signal/multifunction switch flash to pass signal circuit.

The high beam lamps and the high beam indicator on the instrument cluster are always ON.

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

1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the S78 Turn Signal/Multifunction Switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 15 ohms between the ground circuit terminal 3 and ground. If 15 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 15 ohms
3. Ignition ON.
4. Verify the scan tool Headlamps Flash Switch parameter is Inactive. If not Inactive Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module. Test for infinite resistance between the signal circuit terminal 4 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If Inactive
5. Install a 3 A fused jumper wire between the signal circuit terminal 4 and the ground circuit terminal 3.
6. Verify the scan tool Headlamps Flash Switch parameter is Active. If not Active Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal 4 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If Active
7. Test or replace the S78 Turn Signal/Multifunction Switch.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

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

DTC B3881 01

The BCM detects a short to voltage in the left rear tail lamp control circuit.

DTC B3881 02

The BCM detects a short to ground in the left rear tail lamp control circuit.

DTC B3881 04

The BCM detects an open/high resistance in the left rear tail lamp control circuit.

DTC B3882 01

The BCM detects a short to voltage in the right rear tail lamp control circuit.

DTC B3882 02

The BCM detects a short to ground in the right rear tail lamp control circuit.

DTC B3882 04

The BCM detects an open/high resistance in the right rear tail lamp control circuit.

The appropriate tail lamp will not operate.

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

Diagnostic Aids

When testing at the rear tail/stop lamp bulb socket, make sure all measurements and test lamp connections are in the correct terminal location and do not come in contact with each other during testing.

DTC B3881

1. Ignition OFF, exterior lamps OFF, trunk latch latched, remove the E5AA Tail/Stop Lamp bulb - left.
2. Test for less than 5 ohms between the ground circuit at the socket terminal and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit at the socket terminal and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Left Park Lamps ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the E5AA Tail/Stop Lamp - Left.

DTC B3882

1. Ignition OFF, exterior lamps OFF, trunk latch latched, remove the E5AB Tail/Stop Lamp bulb - right.
2. Test for less than 5 ohms between the ground circuit at the socket terminal and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit at the socket terminal and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Right Park Lamps ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X5 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X5 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the E5AB Tail/Stop Lamp - Right.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

Battery voltage must be between 9-16 V.

DTC B3883 01

Headlamp switch in OFF position.

DTC B3883 02 or B3883 04

Headlamp switch in PARK or ON positions.

DTC B3883 01

1. The BCM detects a short to voltage in the license lamps control circuit.
2. The BCM detects an open/high resistance in the license lamps ground circuit.
3. The BCM detects a short to ground or an open/high resistance in the F5DA (BCM 1) fuse B+ circuit.

DTC B3883 02

The BCM detects a short to ground in the license lamps control circuit.

DTC B3883 04

1. The BCM detects an open/high resistance in the license lamps control circuit.
2. The BCM detects an open/high resistance in the license lamps ground circuit.
3. The BCM detects a short to ground or an open/high resistance in the F5DA (BCM 1) fuse B+ circuit.

DTC B3883 01

License lamps always ON.

DTC B3883 02 or B3883 04

License lamps inoperative.

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

1. Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module, ignition ON.
2. Verify a test lamp illuminates between the B+ circuit terminal 1 and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF. Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF. Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If the test lamp illuminates
3. Ignition OFF, connect the X2 harness connector at the K9 Body Control Module.
4. Ignition OFF, exterior lamps OFF, rear hatch latch latched, remove both E7 License Plate Lamp bulbs.
5. Test for less than 5 ohms between each ground circuit terminal 2 and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
6. Connect a test lamp between the E7L License Plate Lamp - Left control circuit terminal 1 and ground, ignition ON.
7. Verify the test lamp turns ON and OFF when commanding the License Plate Lamps ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
8. Ignition OFF.
9. Connect a test lamp between the E7R License Plate Lamp - Right control circuit terminal 1 and ground, ignition ON.
10. Verify the test lamp turns ON and OFF when commanding the License Plate Lamps ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If the test lamp turns ON and OFF
11. Test or replace the appropriate E7 License Plate Lamp bulb.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

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

DTC B3884 01

The BCM detects a short to voltage in the center high mounted stop lamp control circuit.

DTC B3884 02

The BCM detects a short to ground in the center high mounted stop lamp control circuit.

DTC B3884 04

The BCM detects an open/high resistance in the center high mounted stop lamp control circuit.

The BCM will not illuminate the center high mounted stop lamp.

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

1. Ignition OFF, exterior lamps OFF, trunk latch latched, disconnect the harness connector at the E6 Center High Mounted Stop Lamp.
2. Test for less than 5 ohms between the ground circuit terminal B and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit terminal A and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Center Brake Lamp ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the E6 Center High Mounted Stop Lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

Battery voltage must be between 9-16 V.

DTC B3948 01 and B3948 04

1. The BCM detects an open/high resistance in the left front turn signal control circuit.
2. The BCM detects an open/high resistance in the left front turn signal ground circuit.

DTC B3948 02

The BCM detects a short to ground in the left front turn signal control circuit.

DTC B3949 01 and B3949 04

1. The BCM detects an open/high resistance in the right front turn signal control circuit.
2. The BCM detects an open/high resistance in the right front turn signal ground circuit.

DTC B3949 02

The BCM detects a short to ground in the right front turn signal control circuit.

DTC B3948

1. The left front turn signal is inoperative.
2. The left turn signal indicator on the instrument cluster flashes rapidly.

DTC B3949

1. The right front turn signal is inoperative.
2. The right turn signal indicator on the instrument cluster flashes rapidly.

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.

DTC B3948

1. Ignition OFF, exterior lamps OFF, disconnect the harness connector at the E4N turn signal lamp - left front.
2. Test for less than 5 ohms between the ground circuit terminal C and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit terminal B and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Left Front Turn Signal Lamp ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X5 harness connector at the K9 body control module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If the test lamp is always ON Ignition OFF, disconnect the X5 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 body control module. If the test lamp turns ON and OFF
5. Test or replace the E4N turn signal lamp bulb - left front.

DTC B3949

1. Ignition OFF, exterior lamps OFF, disconnect the harness connector at the E4P turn signal lamp - right front.
2. Test for less than 5 ohms between the ground circuit terminal C and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit terminal B and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Right Front Turn Signal Lamp ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X4 harness connector at the K9 body control module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If the test lamp is always ON Ignition OFF, disconnect the X4 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 body control module. If the test lamp turns ON and OFF
5. Test or replace the E4P turn signal lamp bulb - right front.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

Battery voltage must be between 9-16 V.

DTC B3950 01 and B3950 04

1. The BCM detects an open/high resistance in the left rear turn signal control circuit.
2. The BCM detects an open/high resistance in the left rear turn signal ground circuit.

DTC B3950 02

The BCM detects a short to ground in the left rear turn signal control circuit.

DTC B3951 01 and B3951 04

1. The BCM detects an open/high resistance in the right rear turn signal control circuit.
2. The BCM detects an open/high resistance in the right rear turn signal ground circuit.

DTC B3951 02

The BCM detects a short to ground in the right rear turn signal control circuit.

DTC B3950

1. The left rear turn signal is inoperative.
2. The left turn signal indicator on the instrument cluster flashes rapidly.

DTC B3951

1. The right rear turn signal is inoperative.
2. The right turn signal indicator on the instrument cluster flashes rapidly.

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.

Note. When testing at the rear turn signal lamp bulb socket, make sure all measurements and test lamp connections are in the correct terminal location and do not come in contact with each other during testing.

DTC B3950

1. Ignition OFF, exterior lamps OFF, trunk latch latched, remove the E4LR turn signal lamp bulb - left rear.
2. Test for less than 5 ohms between the ground circuit at the socket terminal and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit at the socket terminal and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Left Rear Turn Signal Lamp ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X5 harness connector at the K9 body control module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If the test lamp is always ON Ignition OFF, disconnect the X5 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 body control module. If the test lamp turns ON and OFF
5. Test or replace the E4LR turn signal lamp bulb - left rear.

DTC B3951

1. Ignition OFF, exterior lamps OFF, trunk latch latched, remove the E4RR turn signal lamp bulb - right rear.
2. Test for less than 5 ohms between the ground circuit at the socket terminal and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit at the socket terminal and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Right Rear Turn Signal Lamp ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X4 harness connector at the K9 body control module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If the test lamp is always ON Ignition OFF, disconnect the X4 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 body control module. If the test lamp turns ON and OFF
5. Test or replace the E4RR turn signal lamp bulb - right rear.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

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

DTC C0277 06

1. The BCM detects a short to ground or an open/high resistance in the BPP sensor 5 V reference circuit.
2. The BCM detects a short to ground or an open/high resistance in the BPP sensor signal circuit.

DTC C0277 07

1. The BCM detects a short to voltage in the BPP sensor 5 V reference circuit.
2. The BCM detects a short to voltage in the BPP sensor signal circuit.
3. The BCM detects an open/high resistance in the BPP sensor low reference circuit.

DTC C0277 09

The BCM detects the BPP sensor signal is changing faster than possible under normal operating conditions.

DTC C0277 4B

The DTC will set when the BPP sensor home position is not learned.

DTC C0890 03

The BCM detects a short to ground in the BPP sensor 5 V reference circuit.

DTC C0890 07

1. The BCM detects a short to voltage in the BPP sensor 5 V reference circuit.
2. The BCM detects a short to voltage in the BPP sensor low reference circuit.

1. The Traction Control indicator is commanded ON.
2. For DTC C0277 4B, the stop lamps may not activate at the expected brake pedal positions.

1. The condition responsible for setting the DTC no longer exists.
2. For DTC C0277 07 the ignition must be cycled before the code can be cleared.
3. For DTC C0277 4B a successful brake pedal position sensor calibration has been performed.
4. A history DTC will clear once 50 malfunction-free ignition cycles have occurred.
5. A DTC will not clear the current status until the next ignition cycle.

DTC C0277 06, C0277 07, C0890 03, and C0890 07

1. Ignition OFF, disconnect the harness connector at the B22 brake pedal position sensor, ignition ON.
2. Verify a test lamp illuminates between the appropriate low reference circuit terminal listed below and B+. Terminal 2 - with MH8/MH9 Terminal A - with M26/MZ4 If the test lamp does not illuminate Ignition OFF, disconnect the X1 harness connector at the K9 body control module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If the test lamp illuminates
3. Ignition ON.
4. Test for 4.8-5.2 V between the appropriate 5 V reference circuit terminal listed below and ground. Terminal 1 - with MH8/MH9 Terminal C - with M26/MZ4 If less than 4.8 V Ignition OFF, disconnect the X2 harness connector at the K9 body control module. Test for infinite resistance between the 5 V reference circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the 5 V reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If greater than 5.2 V Ignition OFF, disconnect the X2 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the 5 V reference circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 body control module. If between 4.8-5.2 V
5. Verify the scan tool Brake Pedal Applied parameter is Inactive. If not Inactive Ignition OFF, disconnect the X2 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the appropriate signal circuit terminal listed below and ground. Terminal 3 - with MH8/MH9 Terminal B- with M26/MZ4 If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 body control module. If Active
6. Install a 3 A fused jumper wire between the appropriate 5-volt reference and signal circuit terminals listed below. 5 V reference terminal 1 and signal terminal 3 - with MH8/MH9 5 V reference terminal C and signal terminal B - with M26/MZ4
7. Verify the scan tool Brake Pedal Applied parameter is Active. If not Active Ignition OFF, disconnect the X2 harness connector at the K9 body control module. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If Active
8. Test or replace the B22 brake pedal position sensor.

DTC C0277 4B

1. Verify DTC C0277 4B is not set. If DTC C0277 4B is set Ignition ON Perform the BPP sensor recalibration procedure for the K9 body control module. Refer to «Brake Pedal Position Sensor Calibration»(ref-542483-S01924819902013041600000) . Verify the DTC does not reset while operating the vehicle under the conditions for running the DTC. If the DTC resets, replace the B22 brake pedal position sensor. If the DTC does not reset All OK. If DTC C0277 4B is not set
2. All OK.

DTC C0277 09

1. Verify DTC C0277 09 is not set. If DTC C0277 09 is set Replace the B22 brake pedal position sensor. Perform the BPP sensor recalibration procedure for the K9 body control module. Refer to «Brake Pedal Position Sensor Calibration»(ref-542483-S01924819902013041600000) . Verify the DTC does not reset while operating the vehicle under the conditions for running the DTC. If the DTC resets, replace the K9 body control module. If the DTC does not reset All OK. If DTC C0277 09 is not set
2. All OK.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

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

The BCM detects a short to ground or an open/high resistance on the brake applied signal circuit.

The cruise control system is disabled.

1. The condition responsible for setting the DTC no longer exists.
2. A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.

Verify that the brake pedal position sensor is properly calibrated.

1. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module.
2. Connect a test lamp between the appropriate signal circuit terminal listed below and ground, ignition ON. Terminal 25 - with LUW Terminal 33 - with LUV
3. Verify the test lamp turns ON and OFF while pressing and releasing the brake pedal. If the test lamp is always OFF Ignition OFF, disconnect the X5 harness connector at the K9 Body Control Module. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X5 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
4. Replace the K20 Engine Control Module.

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the lighting system. Refer to «Checking Aftermarket Accessories»(ref-542498-S16706522532013041600000) .
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Symptom List

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

1. «Backup Lamps Malfunction (Automatic Transmission)»(ref-542483-S02930517742013041600000) , «Backup Lamps Malfunction (Manual Transmission)»(ref-542483-S08503517092013041600000)
2. «Courtesy Lamps Malfunction»(ref-542483-S25580865932013041600000)
3. «Daytime Running Lamps Malfunction»(ref-542483-S10723360922013041600000)
4. «Dome Lamps Malfunction»(ref-542483-S11997803282013041600000)
5. «Front Fog Lamps Malfunction»(ref-542483-S26608569252013041600000)
6. «Hazard Lamps Malfunction»(ref-542483-S36834829952013041600000)
7. «Headlamps Malfunction»(ref-542483-S41380545682013041600000)
8. «Interior Backlighting Malfunction»(ref-542483-S27632196502013041600000)
9. «Park, License, and/or Tail Lamps Malfunction»(ref-542483-S02410283162013041600000)
10. «Rear Compartment Lamp Malfunction»(ref-542483-S13540831152013041600000)
11. «Stop Lamps Malfunction»(ref-542483-S35371644352013041600000)
12. «Turn Signal Lamps and/or Indicators Malfunction»(ref-542483-S20746194742013041600000)

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

When testing at the backup lamp bulb socket, make sure all measurements and test lamp connections are in the correct terminal location and do not come in contact with each other during testing.

1. Ignition OFF, disconnect the X5 harness connector at the K9 Body Control Module, ignition ON.
2. Verify a test lamp illuminates between the B+ circuit terminal 4 and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF. Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF. Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If the test lamp illuminates
3. Ignition OFF, connect the X5 harness connector at the K9 Body Control Module.
4. Ignition OFF, exterior lamps OFF, rear hatch latch latched, remove the appropriate E5 Backup Lamp bulb at the appropriate E42 Tail Lamp Assembly.
5. Test for less than 5 ohms between the ground circuit at the socket terminal and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
6. Connect a test lamp between the control circuit at the socket terminal and ground, ignition ON.
7. Verify the test lamp turns ON and OFF when commanding the Backup Lamps ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
8. Test or replace the appropriate E5 Backup Lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

When testing at the backup lamp bulb socket, make sure all measurements and test lamp connections are in the correct terminal location and do not come in contact with each other during testing.

Backup Lamp Switch Malfunction

1. Ignition OFF, exterior lamps OFF, all doors closed, disconnect the harness connector at the B16 Backup Lamp Switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 5 ohms between the ground circuit terminal 2 and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Ignition ON.
4. Verify the scan tool Reverse Position Switch parameter is Off. If not Off Ignition OFF, disconnect the appropriate harness connector listed below at the K20 Engine Control Module. X1 - with LDE/LUW X3 - with LUV Test for infinite resistance between the signal circuit terminal 1 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K20 Engine Control Module. If Off
5. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the ground circuit terminal 2.
6. Verify the scan tool Reverse Position Switch parameter is On. If not On Ignition OFF, disconnect the appropriate harness connector listed below at the K20 Engine Control Module, ignition ON. X1 - with LDE/LUW X3 - with LUV Test for less than 1 V between the signal circuit terminal 1 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If On
7. Test or replace the B16 Backup Lamp Switch.

Backup Lamps Malfunction

1. Ignition OFF, disconnect the X5 harness connector at the K9 Body Control Module, ignition ON.
2. Verify a test lamp illuminates between the B+ circuit terminal 4 and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF. Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF. Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If the test lamp illuminates
3. Ignition OFF, connect the X5 harness connector at the K9 Body Control Module.
4. Ignition OFF, exterior lamps OFF, trunk latch latched, remove the appropriate E5 Backup Lamp bulb at the appropriate E42 Tail Lamp Assembly.
5. Test for less than 5 ohms between the ground circuit at the socket terminal and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
6. Connect a test lamp between the control circuit at the socket terminal and ground, ignition ON.
7. Verify the test lamp turns ON and OFF when commanding the Backup Lamps ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
8. Test or replace the appropriate E5 Backup Lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

1. Ignition OFF, all doors closed, all accessories OFF, disconnect the harness connector at the E37F dome/reading lamps - front and E37 B dome/reading lamps - 2nd row. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the appropriate ground circuit terminal listed below and ground. E37F dome reading lamps - front terminal 2 with C90/C91 E37F dome reading lamps - front terminal 6 with C95 E37B dome reading lamps - 2nd row terminal 2 with C90/C95 If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
3. Connect a test lamp between the appropriate control circuit terminal listed below and ground. E37F dome reading lamps - front terminal 4 with C90/C91 E37F dome reading lamps - front terminal 1 with C95 E37B dome reading lamps - 2nd row terminal 4 with C90/C95
4. Verify the test lamp turns ON and OFF when commanding the Inadvertent Load ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X7 harness connector at the K9 body control module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If the test lamp is always ON Ignition OFF, disconnect the X7 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 body control module. If the test lamp turns ON and OFF
5. Test or replace the inoperative E37 dome/reading lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, open and close drivers door, disconnect the harness connector at the B10 Ambient Light Sensor. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 15 ohms between the ground circuit terminal 6 and ground. If 15 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 15 ohms
3. Ignition ON.
4. Verify the scan tool Ambient Light Sensor parameter is greater than 4.65 V. If 4.65 V or less Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module. Test for infinite resistance between the signal circuit terminal 5 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If greater than 4.65 V
5. Install a 3 A fused jumper wire between the signal circuit terminal 5 and the ground circuit terminal 6.
6. Verify the scan tool Ambient Light Sensor parameter is less than 0.196 V. If 0.196 V or greater Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal 5 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If less than 0.196 V
7. Test or replace the B10 Ambient Light Sensor.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

1. Ignition OFF, all doors closed, all accessories OFF, disconnect the harness connector at the E37F dome/reading lamps - front and E37 B dome/reading lamps - 2nd row. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the appropriate ground circuit terminal listed below and ground. E37F dome reading lamps - front - terminal 2 with C90/C91 E37F dome reading lamps - front - terminal 6 with C95 E37B dome reading lamps - 2nd row - terminal 2 with C90/C95 If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
3. Connect a test lamp between the appropriate control circuit terminal listed below and ground. E37F dome reading lamps - front - terminal 3 with C90/C91 E37F dome reading lamps - front - terminal 2 with C95 E37B dome reading lamps - 2nd row - terminal 3 with C90/C95
4. Verify the test lamp turns ON and OFF when commanding the Courtesy Lamps ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X7 harness connector at the K9 body control module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If the test lamp is always ON Ignition OFF, disconnect the X7 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 body control module. If the test lamp turns ON and OFF
5. Test or replace the inoperative E37 dome/reading lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

Front Fog Lamp Switch Malfunction

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S30 Headlamp Switch, ignition ON.
2. Test for B+ between the B+ circuit terminal 1 and ground. If less than B+ Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module. Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If B+
3. Verify a test lamp does not illuminate between the B+ circuit terminal 1 and the signal circuit terminal 12. If the test lamp illuminates Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If the test lamp does not illuminate
4. Test for B+ between the B+ circuit terminal 1 and the signal circuit terminal 12. If less than B+ Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal 12 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If B+
5. Test or replace the S30 Headlamp Switch.

Front Fog Lamps Malfunction

1. Ignition OFF, disconnect the X5 harness connector at the K9 Body Control Module, ignition ON.
2. Verify a test lamp illuminates between the control circuit terminal 13 and ground. If the test lamp does not illuminate Ignition OFF, disconnect the X2 harness connector at the X50A Fuse Block - Underhood. Test for infinite resistance between the control circuit terminal and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the X50A Fuse Block - Underhood. If the test lamp illuminates
3. Ignition OFF, connect a 3 A fused jumper between the control circuit terminal 13 and ground.
4. Remove the front fog lamp fuse at the X50A Fuse Block - Underhood, ignition ON.
5. Verify a test lamp illuminates between the front fog lamp fuse B+ switch control terminal and ground. If the test lamp does not illuminate Ignition OFF, disconnect the X2 harness connector at the X50A Fuse Block - Underhood, ignition ON. Test for less than 1 V between the control circuit terminal 13 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the X50A Fuse Block - Underhood. If the test lamp illuminates
6. Ignition OFF, connect the X5 harness connector at the K9 Body Control Module.
7. Install the front fog lamp fuse at the X50A Fuse Block - Underhood.
8. Disconnect the harness connector at the appropriate E29 Fog Lamp, ignition OFF, exterior lamps OFF.
9. Test for less than 5 ohms between the ground circuit terminal 1 and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
10. Connect a test lamp between the control circuit terminal 2 and ground, ignition ON.
11. Verify the test lamp turns ON and OFF when commanding the Front Fog Lamps ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X1 harness connector at the X50A Fuse Block - Underhood. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X1 harness connector at the X50A Fuse Block - Underhood, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
12. Test or replace the appropriate E29 Fog Lamp.

Front Fog Lamp Indicator Malfunction

1. Ignition ON.
2. Verify the front fog lamp indicator turns ON and OFF when commanding the Instrument Cluster All Indicators Test ON and OFF with a scan tool. If the front fog lamp indicator is always OFF or remains ON Replace the P16 Instrument Cluster. If the front fog lamp indicator turns ON and OFF
3. Replace the K9 Body Control Module.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

Hazard Warning Switch Malfunction

1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the S26 Hazard Warning Switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 5 ohms between the ground circuit terminal 3 and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Ignition ON.
4. Verify the scan tool Hazard Lamps Switch parameter is Inactive. If not Inactive Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module. Test for infinite resistance between the signal circuit terminal 1 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If Inactive
5. Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground.
6. Verify the scan tool Hazard Lamps Switch parameter is Active. If not Active Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal 1 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If Active
7. Test or replace the S26 Hazard Warning Switch.

Hazard Warning Switch Backlighting Malfunction

1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the S26 Hazard Warning Switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 5 ohms between the ground circuit terminal 3 and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit terminal 2 and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Hazard Lamps Switch Backlight ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the S26 Hazard Warning Switch.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

Headlamp Switch Malfunction

1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the S30 headlamp switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 15 ohms between the ground circuit terminal 6 and ground. If 15 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 15 ohms
3. Ignition ON.
4. Verify the scan tool Automatic Headlamps Disable Switch parameter is Inactive. If not Inactive Ignition OFF, disconnect the X1 harness connector at the K9 body control module. Test for infinite resistance between the signal circuit terminal 5 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 body control module. If Inactive
5. Install a 3 A fused jumper wire between the signal circuit terminal 5 and the ground circuit terminal 6.
6. Verify the scan tool Automatic Headlamps Disable Switch parameter is Active. If not Active Ignition OFF, disconnect the X1 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the signal circuit terminal 5 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If Active
7. Verify the scan tool Park Lamps Switch parameter is Inactive. If not Inactive Ignition OFF, disconnect the X1 harness connector at the K9 body control module. Test for infinite resistance between the signal circuit terminal 3 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 body control module. If Inactive
8. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the ground circuit terminal 6.
9. Verify the scan tool Park Lamps Switch parameter is Active. If not Active Ignition OFF, disconnect the X1 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the signal circuit terminal 3 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If Active
10. Verify the scan tool Headlamps On Switch parameter is Inactive. If not Inactive Ignition OFF, disconnect the X1 harness connector at the K9 body control module. Test for infinite resistance between the signal circuit terminal 4 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 body control module. If Inactive
11. Install a 3 A fused jumper wire between the signal circuit terminal 4 and the ground circuit terminal 6.
12. Verify the scan tool Headlamps On Switch parameter is Active. If not Active Ignition OFF, disconnect the X1 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the signal circuit terminal 4 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If Active
13. Test or replace the S30 headlamp switch.

Turn Signal/Multifunction Switch Malfunction

1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the S78 turn signal/multifunction switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 15 ohms between the ground circuit terminal 3 and ground. If 15 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 15 ohms
3. Ignition ON.
4. Verify the scan tool High Beam Select Switch parameter is Inactive. If not Inactive Ignition OFF, disconnect the X3 harness connector at the K9 body control module. Test for infinite resistance between the signal circuit terminal 2 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 body control module. If Inactive
5. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the ground circuit terminal 3.
6. Verify the scan tool High Beam Select Switch parameter is Active. If not Active Ignition OFF, disconnect the X3 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the signal circuit terminal 2 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If Active
7. Verify the scan tool Headlamps Flash Switch parameter is Inactive. If not Inactive Ignition OFF, disconnect the X3 harness connector at the K9 body control module. Test for infinite resistance between the signal circuit terminal 4 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 body control module. If Inactive
8. Install a 3 A fused jumper wire between the signal circuit terminal 4 and the ground circuit terminal 3.
9. Verify the scan tool Headlamps Flash Switch parameter is Active. If not Active Ignition OFF, disconnect the X3 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the signal circuit terminal 4 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If Active
10. Test or replace the S78 turn signal/multifunction switch.

Headlamps Malfunction - Low Beam

1. Ignition OFF, disconnect the X1 harness connector at the K9 body control module, ignition ON.
2. Verify a test lamp illuminates between the B+ circuit terminal 2 and ground. If the test lamp does not illuminate and the circuit fuse is good Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 body control module. If the test lamp illuminates
3. Verify a test lamp illuminates between the B+ circuit terminal 3 and ground. If the test lamp does not illuminate and the circuit fuse is good Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 body control module. If the test lamp illuminates
4. Ignition OFF, connect the X1 harness connector at the K9 body control module.
5. Ignition OFF, exterior lamps OFF, disconnect the harness connector at the appropriate E13 headlamp.
6. Test for less than 5 ohms between the ground circuit terminal D and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
7. Connect a test lamp between the control circuit terminal A and ground, ignition ON.
8. Verify the test lamp turns ON and OFF when commanding the appropriate Low Beam/Daytime Running Lamp ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X4 harness connector at the K9 body control module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If the test lamp is always ON Ignition OFF, disconnect the X4 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 body control module. If the test lamp turns ON and OFF
9. Test or replace the appropriate E4 headlamp - low beam.

Headlamps Malfunction - High Beam

1. Ignition OFF, remove the KR48 headlamp high beam relay.
2. Connect a test lamp between the control circuit terminal 86 and B+, ignition ON.
3. Verify the test lamp turns ON and OFF when commanding the High Beams ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X5 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Ignition OFF. Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If the test lamp is always ON Ignition OFF, disconnect the X5 harness connector at the K9 body control module. Test for infinite resistance between the control circuit terminal and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 body control module. If the test lamp turns ON and OFF
4. Ignition OFF, exterior lamps OFF, connect the KR48 headlamp high beam relay.
5. Disconnect the harness connector at the appropriate E13 headlamp.
6. Test for less than 5 ohms between the ground circuit terminal D and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
7. Connect a test lamp between the control circuit terminal B and ground, ignition ON.
8. Verify the test lamp turns ON and OFF when commanding the High Beams ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X1 harness connector at the X50A fuse block - underhood. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the KR48 headlamp high beam relay. If the test lamp is always ON Ignition OFF, disconnect the X1 harness connector at the X50A fuse block - underhood, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the KR48 headlamp high beam relay. If the test lamp turns ON and OFF
9. Test or replace the appropriate E4 headlamp - high beam.

High Beam Indicator Malfunction

1. Ignition ON.
2. Verify the high beam indicator turns ON and OFF when commanding the Instrument Cluster All Indicators Test ON and OFF with a scan tool. If the high beam indicator is always OFF or remains ON Replace the P16 instrument cluster. If the high beam indicator turns ON and OFF
3. Replace the K9 body control module.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

Dimmer Switch Malfunction

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S30 Headlamp Switch, ignition ON.
2. Test for B+ between the B+ circuit terminal 1 and ground. If less than B+ Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module. Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If B+
3. Verify a test lamp does not illuminate between the B+ circuit terminal 1 and the signal circuit terminal 12. If the test lamp illuminates Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If the test lamp does not illuminate
4. Test for B+ between the B+ circuit terminal 1 and the signal circuit terminal 12. If less than B+ Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal 12 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If B+
5. Test or replace the S30 Headlamp Switch.

Interior Backlighting Malfunction

1. Ignition OFF, all doors closed, all accessories OFF, disconnect the harness connector at the component with inoperative backlighting. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 15 ohms between the appropriate ground circuit terminal listed below and ground. S13D Door Lock Switch - Driver terminal 1 S30 Headlamp Switch - terminal 6 S48E Multifunction Switch - Center Console terminal 9 S70R Steering Wheel Controls Switch - right terminal 5 S70L Steering Wheel Controls Switch - left terminal 7 If 15 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 15 ohms
3. Connect a test lamp between the appropriate control circuit terminal listed below and ground. K33 HVAC Control Module - terminal 8 S13D Door Lock Switch - Driver terminal 2 S30 Headlamp Switch - terminal 7 S48E Multifunction Switch - Center Console terminal 10 S70R Steering Wheel Controls Switch - Right terminal 4 S70L Steering Wheel Controls Switch - Left terminal 6
4. Verify the test lamp turns ON and OFF when commanding the LED Backlight Dimming ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the component with inoperative backlighting.

Hazard Lamps Switch Backlighting Malfunction

1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the S26 Hazard Warning Switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 5 ohms between the ground circuit terminal 3 and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit terminal 2 and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Hazard Lamps Switch Backlight ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the S26 Hazard Warning Switch.

Transmission Shift Lever Position Indicator Backlighting Malfunction

1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the P2 Transmission Shift Lever Position Indicator. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 15 ohms between the ground circuit terminal 2 and ground. If 15 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 15 ohms
3. Connect a test lamp between the control circuit terminal 1 and ground.
4. Verify the test lamp turns ON and OFF while turning the headlamp switch ON and OFF. If the test lamp is always OFF Ignition OFF, disconnect the X6 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X6 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the P2 Transmission Shift Lever Position Indicator.

Passenger Air Bag Disable Indicator Backlighting Malfunction

1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the P14 Passenger Air Bag Disable Indicator. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 5 ohms between the ground circuit terminal 3 and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit terminal 1 and ground.
4. Verify the test lamp turns ON and OFF while turning the ignition switch ON and OFF. If the test lamp is always OFF Ignition OFF. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If the test lamp is always ON Ignition OFF, remove the F28DA at the X51A Fuse Block - Instrument Panel, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the X51A Fuse Block - Instrument Panel. If the test lamp turns ON and OFF
5. Test or replace the P14 Passenger Air Bag Disable Indicator.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

When testing at the park lamp bulb socket, make sure all measurements and test lamp connections are in the correct terminal location and do not come in contact with each other during testing.

Park Lamp Switch Malfunction

1. Ignition OFF, all doors closed, all accessories OFF, disconnect the harness connector at the S30 Headlamp Switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 15 ohms between the ground circuit terminal 6 and ground. If 15 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 15 ohms
3. Ignition ON.
4. Verify the scan tool Park Lamps Switch parameter is Inactive. If not Inactive Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module. Test for infinite resistance between the signal circuit terminal 3 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 Body Control Module. If Inactive
5. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the ground circuit terminal 6.
6. Verify the scan tool Park Lamps Switch parameter is Active. If not Active Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal 3 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If Active
7. Test or replace the S30 Headlamp Switch.

Park Lamps Malfunction

1. Ignition OFF, exterior lamps OFF, rear hatch latch latched, disconnect the harness connector at the appropriate park lamp.
2. Test for less than 5 ohms between the appropriate ground circuit terminal listed below and ground. E4N Park/Turn Signal Lamp - Left Front terminal C E4P Park/Turn Signal Lamp - Right Front terminal C E5AA Tail/Stop Lamp - Left socket terminal E5AB Tail/Stop Lamp - Right socket terminal E2LR Side Marker Lamp - Left Rear socket terminal E2RR Side Marker Lamp - right rear socket terminal If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the appropriate control circuit terminal listed below and ground, ignition ON. E4N Park/Turn Signal Lamp - Left Front terminal A E4P Park/Turn Signal Lamp - Right Front terminal A E5AA Tail/Stop Lamp - Left socket terminal E5AB Tail/Stop Lamp - Right socket terminal E2LR Side Marker Lamp - Left Rear socket terminal E2RR Side Marker Lamp - Right Rear socket terminal
4. Verify the test lamp turns ON and OFF when commanding the appropriate Park Lamps ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the appropriate harness connector listed below at the K9 Body Control Module. X4 X5 Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the appropriate harness connector listed below at the K9 Body Control Module, ignition ON. X4 X5 Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the appropriate park lamp.

License Plate Lamps Malfunction

1. Ignition OFF, exterior lamps OFF, trunk latch latched, remove both E7 License Plate Lamp bulbs.
2. Test for less than 5 ohms between each ground circuit terminal 1 and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the license plate lamp - left control circuit terminal 2 and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the License Plate Lamps ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Connect a test lamp between the license plate lamp - right control circuit terminal 2 and ground, ignition ON.
6. Verify the test lamp turns ON and OFF when commanding the License Plate Lamps ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp turns ON and OFF
7. Test or replace the appropriate E7 License Plate Lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

1. Ignition OFF, exterior lamps OFF, trunk latch latched, disconnect the harness connector at the E8S Rear Compartment Courtesy Lamp.
2. Test for less than 5 ohms between the ground circuit terminal 2 and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit terminal 1 and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Trunk Lamp ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the E8S Rear Compartment Courtesy Lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

When testing at the stop lamp bulb socket, make sure all measurements and test lamp connections are in the correct terminal location and do not come in contact with each other during testing.

Brake Pedal Position Sensor Malfunction

1. Ignition OFF, disconnect the harness connector at the B22 Brake Pedal Position Sensor, ignition ON.
2. Test for less than 1 V between the appropriate low reference circuit terminal listed below and ground. Terminal 2 - with MH9 Terminal A - without MH9 If 1 V or greater Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the low reference circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If less than 1 V
3. Test or replace the B22 Brake Pedal Position Sensor.

Stop Lamps Malfunction

1. Ignition OFF, exterior lamps OFF, trunk latch latched, remove the appropriate E5A Tail/Stop Lamp bulb.
2. Test for less than 5 ohms between the ground circuit at the socket terminal and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit at the socket terminal and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the appropriate Rear Brake/Park Lamp ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the appropriate harness connector listed below at the K9 Body Control Module. X4 left stop lamp X5 right stop lamp Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the appropriate harness connector listed below at the K9 Body Control Module, ignition ON. X4 left stop lamp X5 right stop lamp Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the appropriate E5A Tail/Stop Lamp.

Center High Mount Stop Lamp Malfunction

1. Ignition OFF, exterior lamps OFF, trunk latch latched, disconnect the harness connector at the E6 Center High Mounted Stop Lamp.
2. Test for less than 5 ohms between the ground circuit terminal B and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
3. Connect a test lamp between the control circuit terminal A and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Center Brake Lamp ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 Body Control Module. If the test lamp is always ON Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module, ignition ON. Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 Body Control Module. If the test lamp turns ON and OFF
5. Test or replace the E6 Center High Mounted Stop Lamp.

1. Perform the «Diagnostic System Check - Vehicle»(ref-542476-S03610919532013041600000) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(ref-542476-S11988299792013041600000) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(ref-542476-S27446858652013041600000) provides an overview of each diagnostic category.

When testing at the turn signal lamp bulb socket, make sure all measurements and test lamp connections are in the correct terminal location and do not come in contact with each other during testing.

Turn Signal/Multifunction Switch Malfunction

1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the S78 turn signal/multifunction switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 15 ohms between the ground circuit terminal 3 and ground. If 15 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 15 ohms
3. Ignition ON.
4. Verify the scan tool Left Turn Signal Switch parameter is Inactive. If not Inactive Ignition OFF, disconnect the X3 harness connector at the K9 body control module. Test for infinite resistance between the signal circuit terminal 1 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 body control module. If Inactive
5. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the ground circuit terminal 3.
6. Verify the scan tool Left Turn Signal Switch parameter is Active. If not Active Ignition OFF, disconnect the X3 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the signal circuit terminal 1 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If Active
7. Verify the scan tool Right Turn Signal Switch parameter is Inactive. If not Inactive Ignition OFF, disconnect the X3 harness connector at the K9 body control module. Test for infinite resistance between the signal circuit terminal 7 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 body control module. If Inactive
8. Install a 3 A fused jumper wire between the signal circuit terminal 7 and the ground circuit terminal 3.
9. Verify the scan tool Right Turn Signal Switch parameter is Active. If not Active Ignition OFF, disconnect the X3 harness connector at the K9 body control module, ignition ON. Test for less than 1 V between the signal circuit terminal 7 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If Active
10. Test or replace the S78 turn signal/multifunction switch.

Turn Signal Lamps Malfunction

1. Ignition OFF, disconnect the X1 harness connector at the K9 body control module, ignition ON.
2. Verify a test lamp illuminates between the B+ circuit terminal 2 and ground. If the test lamp does not illuminate and the circuit fuse is good Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 body control module. If the test lamp illuminates
3. Verify a test lamp illuminates between the B+ circuit terminal 3 and ground. If the test lamp does not illuminate and the circuit fuse is good Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 body control module. If the test lamp illuminates
4. Ignition OFF, connect the X1 harness connector at the K9 body control module.
5. Disconnect the X5 harness connector at the K9 body control module, ignition ON.
6. Verify a test lamp illuminates between the B+ circuit terminal 3 and ground. If the test lamp does not illuminate and the circuit fuse is good Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 body control module. If the test lamp illuminates
7. Verify a test lamp illuminates between the B+ circuit terminal 4 and ground. If the test lamp does not illuminate and the circuit fuse is good Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K9 body control module. If the test lamp illuminates
8. Ignition OFF, connect the X5 harness connector at the K9 body control module.
9. Ignition OFF, exterior lamps OFF, trunk latch latched, disconnect the harness connector at the appropriate E4 turn signal lamp.
10. Test for less than 5 ohms between the appropriate ground circuit terminal listed below and ground. E4N park/turn signal lamp - left terminal C E4P park/turn signal lamp - right terminal C E4LR turn signal lamp - left rear socket terminal E4RR turn signal lamp - right rear socket terminal If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
11. Connect a test lamp between the appropriate control circuit terminal listed below and ground. E4N park/turn signal lamp - left terminal B E4P park/turn signal lamp - right terminal B E4LR turn signal lamp - left rear socket terminal E4RR turn signal lamp - right rear socket terminal
12. Verify the test lamp turns ON and OFF when commanding the appropriate Turn Signal Lamp ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the appropriate harness connector listed below at the K9 body control module. X5 left turn signals X4 right turn signals Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K9 body control module. If the test lamp is always ON Ignition OFF, disconnect the appropriate harness connector listed below at the K9 body control module, ignition ON. X5 left turn signals X4 right turn signals Test for less than 1 V between the control circuit terminal and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K9 body control module. If the test lamp turns ON and OFF
13. Test or replace the appropriate E4 turn signal lamp.

Turn Signal Indicators Malfunction

1. Ignition ON.
2. Verify the left and right turn signal indicators turn ON and OFF while commanding the All Indicators Test ON and OFF with a scan tool. If the left or right turn signal indictors are always OFF or remain ON Replace the P16 instrument cluster. If the left and right turn signal indictors turn ON and OFF
3. Replace the K9 body control module.