Orlando

DTC B2740

The front fog lamp relay is supplied with battery voltage at all times. The front fog lamp switch signal circuit is grounded through a resistor momentarily by pressing the front fog lamp switch. The body control module (BCM) energises the front fog lamp relay by applying ground to the front fog lamp relay control circuit. When the front fog lamp relay is energised, the relay switch contacts close and battery voltage is applied through the front fog lamp fuse to the front fog lamp supply voltage circuit which illuminates the front fog lamps.

Front fog lamp switch stuck.

The front fog lamps are inoperative.

The condition for setting the DTC is not longer present.

Schematic Reference

Fog Lamps Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Exterior Lighting Systems Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool Front Fog Lamps Switch parameter. The reading should change between Active/Inactive when changing between pressed and released front fog lamp switch button.

1. Ignition OFF, disconnect the X1 and X3 harness connectors at the K9 Body Control Module.
2. Ignition ON, test for less than 0.3 V between the signal circuit terminal 9 X1 and ground.

⇒	If greater than the specified value, test the circuits listed below for a short to voltage. If the circuit tests normal, replace the S30 Headlamp Switch.

•	Signal circuit terminal 9 X1

•	12 V reference voltage circuit terminal 4 X3

3. Ignition OFF, test for infinite resistance between the signal circuit terminal 9 X1 and ground.

⇒	If less than infinite resistance, test the circuits listed below for a short to ground. If the circuit tests normal, replace the S30 Headlamp Switch.

•	Signal circuit terminal 9 X1

•	12 V reference voltage circuit terminal 4 X3

4. Test for 7.4-7.9 kΩ between the signal circuit terminal 9 X1 and the 12 V reference voltage circuit terminal 4 X3.

⇒	If less than 7.4 kΩ, test the signal circuit and the 12 V reference circuit for a short circuit. If the circuit tests normal, replace the S30 Headlamp Switch.

⇒	If greater than 7.9 kΩ, test the signal circuit and the 12 V reference circuit for an open/high resistance. If the circuit tests normal, replace the S30 Headlamp Switch.

5. Test for 2.7-3.1 kΩ between the signal circuit terminal 9 X1 and the 12 V reference voltage circuit terminal 4 X3 while pressing the front fog lamp switch.

⇒	If not the specified range, replace the S30 Headlamp Switch.

6. If all circuits test normal, replace the K9 Body Control Module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.