2010 Cadillac Truck SRX AWD V6-3.0L Page 299
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.
Component Testing
Relay Test
1. Ignition OFF, disconnect the KR49 headlamp low beam relay.
2. Test for 60-180 ohm between terminals 85 and 86.
瀚慖f not within the specified range, replace the KR49 headlamp low beam relay.
3. Test for infinite resistance between the following terminals:
* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87
瀚慖f not the specified value, replace the KR49 headlamp low beam relay.
4. Install a 15A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground. Test for
less than 2 ohm between terminals 30 and 87.
瀚慖f greater than the specified range, replace the KR49 headlamp low beam relay.
