Cruze

DTC B3948 or B3949

Ground is applied at all times to the indicator/multifunction switch. When the indicator/multifunction switch is placed in either the turn right or turn left position, ground is applied to the body control module (BCM) through either the right turn or left indicator switch signal circuit. The BCM then applies a voltage to the front/side and rear indicator lamps through their respective voltage supply circuits.

B3948 01 and B3949 01

The appropriate indicator is inactive.

B3948 02, B3948 04, B3949 02 and B3949 04

The appropriate indicator is active.

B3948 01 and B3949 01

The BCM detects a short to voltage on the control circuit.

B3948 02 and B3949 02

The BCM detects a short to ground on the control circuit.

B3948 04 and B3949 04

The BCM detects an open control circuit.

The appropriate indicator is inoperative.

The condition for setting the DTC is no longer present.

Schematic Reference

Exterior 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, command the Left Front Indicator Lamp test. The left front indicator lamp and indicator repeater light should be ON/OFF.

Ignition ON, command the Right Front Indicator Lamp test. The right front indicator lamp and indicator repeater light should be ON/OFF.

1. Ignition OFF, disconnect the harness connector at the appropriate indicator lamp.
2. Test for less than 5 Ω between the appropriate indicator lamp ground circuit harness connector listed below and ground.

•	E4LF Indicator Lamp - Left Front ground circuit harness connector terminal 2

•	E4Y Indicator Repeater Lamp - Left ground circuit harness connector terminal 2

•	E4RF Indicator Lamp - Right Front ground circuit harness connector terminal 2

•	E4Z Indicator Repeater Lamp - Right ground circuit harness connector terminal 2

⇒	If greater than the specified value, test the ground circuit for an open/high resistance.

3. Connect a test lamp between the appropriate indicator lamp control circuit harness connector listed below and ground.

•	E4LF Indicator Lamp - Left Front circuit harness connector terminal 1

•	E4Y Indicator Repeater Lamp - Left circuit harness connector terminal 1

•	E4RF Indicator Lamp - Right Front circuit harness connector terminal 1

•	E4Z Indicator Repeater Lamp - Right circuit harness connector terminal 1

4. Command the appropriate Indicator Lamp test ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K9 Body Control Module.

⇒	If the test lamp is always OFF, test the signal circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the K9 Body Control Module.

5. If all the circuits test normal, replace the appropriate indicator lamp.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.