DTC B199A or B199B

Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. DTC Descriptors DTC B199A Left Rear Turn Signal Lamp Control Circuit DTC B199B Right Rear Turn Signal Lamp Control Circuit Refer to Symptom Byte List for symptom byte information. Diagnostic Fault Information

Circuit	Circuit Function	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performan
1334	Control	B199A 11	1	1	—
1335	Control	B199B 11	1	1	—
1950	Ground	—	1	—	—
2050	Ground	—	1	—	—
1. Turn Signal Malfunction

Scan Tool Functions K219 Lighting Control Module – Control Functions – Exterior Lighting

Control Function	Description
Left Rear Turn Signal Lamp	This control function will control the left rear turn signal ON/OFF
Right Rear Turn Signal Lamp	This control function will control the right rear turn signal ON/OFF

Circuit/System Description Ground is applied at all times to the turn signal switch. The turn signal lamps may only be activated with the ignition on/vehicle in service mode. When the turn signal switch is placed in either the turn right or turn left position, ground is applied to the K9 Body Control Module (BCM) through either the right turn or left turn signal switch signal circuit. The BCM responds to the turn signal switch input by sending a serial data message to the K219 Lighting Control Module to command the appropriate turn signals ON and OFF. The Lighting Control Module responds by applying a pulsating voltage to the front, rear, and mirror turn signal lamps through their respective control circuits. When a turn signal request is received by the BCM, a serial data message is also sent to the instrument cluster requesting the respective turn signal indicator be pulsed ON and OFF. Conditions for Running the DTC Battery voltage must be between 9-16 V. Conditions for Setting the DTC DTC B199A 11 The Lighting Control Module detects a short to ground on circuit 1334. DTC B199A 13 The Lighting Control Module detects an open/high resistance on circuit 1334. DTC B199B 11 The Lighting Control Module detects a short to ground on circuit 1335. DTC B199B 13 The Lighting Control Module detects an open/high resistance on circuit 1335. Actions Taken When the DTC Sets DTC B199A The left rear turn signal is inoperative. The “Left Rear Turn Indicator Failure” message is displayed on the driver information center display. The left turn signal indicator on the instrument cluster flashes rapidly DTC B199B The right rear turn signal is inoperative. The “Right Rear Turn Indicator Failure” message is displayed on the driver information center display. The right turn signal indicator on the instrument cluster flashes rapidly Conditions for Clearing the DTC The condition responsible for setting the DTC no longer exists. A history DTC will clear once 40 consecutive malfunction-free ignition cycles have occurred. Reference Information Schematic Reference Exterior Lights Schematics Connector End View Reference Master Electrical Component List Description and Operation Exterior Lighting Systems Description and Operation Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs Scan Tool Reference Control Module References for scan tool information Circuit/System Testing DTC B199A

Ignition OFF, exterior lamps OFF, disconnect the E42L Rear Body Structure Stop Lamp - Left.
Verify a test lamp illuminates between ground circuit terminal 1 and B+. ⇒ If the test lamp does not illuminate 2.1. Repair the open/high resistance on the ground circuit or ground connection. ⇓ If the test lamp illuminates
Connect a test lamp between control circuit terminal 5 and ground, ignition ON.
Verify the test lamp turns ON and OFF when commanding the Left Rear Turn Signal ON and OFF with a scan tool. ⇒ If the test lamp is always OFF 4.1. Test circuit 1334 for a short to ground. ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found 4.2. Test circuit 1334 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found 4.3. Replace the K219 Lighting Control Module. ⇒ If the test lamp is always ON 4.1. Test circuit 1334 for a short to voltage. ⇒ If a short to voltage is found, repair the fault on the circuit. ⇓ If a short to voltage is not found 4.2. Replace the K219 Lighting Control Module. ⇓ If the test lamp turns ON and OFF
Replace the left rear turn signal bulb. DTC B199B
Ignition OFF, exterior lamps OFF, disconnect the E42R Rear Body Structure Stop Lamp - Right.
Verify a test lamp illuminates between ground circuit terminal 1and B+. ⇒ If the test lamp does not illuminate 2.1. Repair the open/high resistance on the ground circuit or ground connection. ⇓ If the test lamp illuminates
Connect a test lamp between control circuit terminal 5 and ground, ignition ON.
Verify the test lamp turns ON and OFF when commanding the Right Rear Turn Signal ON and OFF with a scan tool. ⇒ If the test lamp is always OFF 4.1. Test circuit 1335 for a short to ground. ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found 4.2. Test circuit 1335 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found 4.3. Replace the K219 Lighting Control Module. ⇒ If the test lamp is always ON 4.1. Test circuit 1335 for a short to voltage. ⇒ If a short to voltage is found, repair the fault on the circuit. ⇓ If a short to voltage is not found 4.2. Replace the K219 Lighting Control Module. ⇓ If the test lamp turns ON and OFF
Replace the right rear turn signal bulb. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Lighting Component Replacement Reference Control Module References for BCM replacement, programming, and setup