DTC B19C4
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 Descriptor DTC B19C4 Rear Fog Lamp Control 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 |
|---|---|---|---|---|---|
| 122 | Control | B19C4 11 | B19C4 13 | B19C4 12 | — |
| 1450 | Ground | — | B19C4 13 | — | — |
Scan Tool Functions K219 Lighting Control Module – Control Functions – Exterior Lighting
| Control Function | Description |
|---|---|
| Rear Fog Lamp(s) | This control function will control the rear fog lamp(s) ON/OFF |
Circuit/System Description The S30 Headlamp Switch is used to control the fog lights when equipped (T79/T40). When a dimming/fog light button is pressed, the signal circuit becomes grounded through the appropriate resistor internal to the headlight switch and voltage from the BCM will decrease accordingly. The BCM interprets the signal and responds by sending a serial data message to the K219 Lighting Control Module. The lighting control module responds by applying pulse width modulated (PWM) voltage to the appropriate fog light(s). Conditions for Running the DTC Battery voltage must be between 9-16 V. Rear fog lamps on. Conditions for Setting the DTC DTC B19C4 11 The Lighting Control Module detects a short to ground on circuit 122. DTC B19C4 12 The Lighting Control Module detects a short to voltage on circuit 122. DTC B19C4 13 The Lighting Control Module detects an open/high resistance on circuit 122. Actions Taken When the DTC Sets The rear fog lamps will be inoperative. 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 Fog 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
- Ignition OFF, disconnect the connector at the appropriate component: E93AL Rear Fascia Lower Signal Lamp – Left E93AR Rear Fascia Lower Signal Lamp – Right
- Verify a test lamp illuminates between ground circuit terminal 2 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 1 and ground, ignition on.
- Verify the test lamp turns on and off when commanding the Rear Fog Lamp(s) on and off with a scan tool. ⇒ If the test lamp is always OFF 4.1. Test circuit 122 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 122 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 122 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 appropriate rear fog lamp. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Lighting Component Replacement Reference Control Module References for BCM replacement, programming, and setup