2010 Cadillac Truck SRX FWD V6-3.0L Page 296

2010 Cadillac Truck SRX FWD V6-3.0L Page 296

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Ignition ON, observe the function of the low beam headlamps while commanding the Low Beam Lamps ON and OFF with a scan tool. The E4G

headlamp-left low beam and the E4H headlamp-right low beam should turn ON and OFF while changing between the commanded states.

If the E4G headlamp-left low beam is always OFF, refer to Left Low Beam Inoperative

If the E4H headlamp-right low beam is always OFF, refer to Right Low Beam Inoperative

If both low beam headlamps are always ON or always OFF, refer to Headlamps Malfunction

Circuit/System Testing

Left Low Beam Inoperative

1. Ignition OFF, disconnect the X118 inline harness connector at the E4G headlamp-left low beam.

2. Connect a test lamp between the control circuit terminal G and ground.

3. Ignition ON, command the Low Beam Lamps ON with a scan tool, the test should illuminate while commanding the headlamp ON.

瀚慖f the test lamp does not illuminate and the circuit fuse is good, test the control circuit for an open/high resistance.

瀚慖f the test lamp does not illuminate and the circuit fuse is open, test the control circuit for a short to ground.

4. If all circuits test normal, replace the E4G headlamp-left low beam.

Right Low Beam Inoperative

1. Ignition OFF, disconnect the X120 inline harness connector at the E4H headlamp-right low beam.

2. Connect a test lamp between the control circuit terminal G and ground.

3. Ignition ON, command the Low Beam Lamps ON with a scan tool, the test should illuminate while commanding the headlamp ON.

瀚慖f the test lamp does not illuminate and the circuit fuse is good, test the control circuit for an open/high resistance.

瀚慖f the test lamp does not illuminate and the circuit fuse is open, test the control circuit for a short to ground.

4. If all circuits test normal, replace the E4H headlamp-right low beam.

Headlamps Malfunction

1. Ignition OFF, disconnect the KR49 headlamp low beam relay.

2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 30 and ground.

瀚慖f the test lamp illuminates, test the control circuit for a short to voltage

3. Verify that a test lamp illuminates between the B+ circuit terminal 87 and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.e

4. Verify that a test lamp illuminates between the B+ circuit terminal 86 and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for an open/high resistance.

5. Connect a 15A fused jumper wire between the B+ circuit terminal 87 and the control circuit terminal 30. Verify the E4G headlamp-left low

beam and the E4H headlamp-right low beam are activated.

瀚慖f the E4G headlamp-left low beam and the E4H headlamp-right low beam do not activate, test the control circuit for a short to ground or

an open/high resistance.

6. Connect a test lamp between the B+ circuit terminal 86 and the control circuit terminal 85.

7. Ignition ON, command the Low Beam Lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between

the commanded states.

瀚慖f the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K9 BCM.

瀚慖f the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace

the K9 BCM.

8. If all circuits test normal, test or replace the KR49 headlamp low beam relay.