Circuit/System Testing

Dimmer Switch Malfunction

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S30 headlamp switch, ignition ON.
2. Test for B+ between the B+ circuit terminal 1 and ground.
   • If less than B+ 
   1. Ignition OFF, disconnect the X3 harness connector at the K9 body control module.
   2. Test for infinite resistance between the B+ circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
   3. Test for less than 2 Ω in the B+ circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 body control module.
   • If B+ 
3. Verify the scan tool LED Backlight Dimming Command parameter is greater than 40%.
   • If 40% or less 
   1. Ignition OFF, disconnect the X1 harness connector at the K9 body control module, ignition ON.
   2. Test for less than 1 V between the signal circuit terminal 12 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K9 body control module.
   • If greater than 40% 
4. Install a 3 A fused jumper wire between the signal circuit terminal 12 and the B+ circuit terminal 1.
5. Verify the scan tool LED Backlight Dimming Command parameter is less than 30%.
   • If 30% or greater 
   1. Ignition OFF, disconnect the X1 harness connector at the K9 body control module.
   2. Test for infinite resistance between the signal circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
   3. Test for less than 2 Ω in the signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 body control module.
   • If less than 30% 
6. Test or replace the S30 headlamp switch.

Interior Backlighting Malfunction

NOTE:
Each component with backlighting may need to be disconnected to isolate a short to voltage or short to ground. Use the schematics to identify the following:
• Backlighting components the vehicle is equipped with
• Each component's control and ground circuit terminals
• Component locations on the backlighting control circuit
1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the component with inoperative backlighting. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 5 Ω between the appropriate ground circuit terminal listed below and ground.
   • S30 headlamp switch - terminal 6
   • E37F dome/reading lamps - front - terminal 6
   • E1D accent lamp - driver door - terminal 2
   • E1P accent lamp - passenger door - terminal 2
   • E1Q accent lamp - console cupholder left - terminal 2
   • E1S accent lamp - console cupholder right - terminal 2
   • S88 sunroof tilt switch - terminal 3
   • S72 sunroof switch - terminal 3
   • S13D door lock switch - driver- terminal 4
   • S13P door lock switch - passenger - terminal 4
   • S70R steering wheel controls switch - right - terminal 5
   • S70L steering wheel controls switch - left - terminal 7
   • S91 park brake control switch - terminal 8
   • S48A multifunction switch - instrument panel - terminal 1
   • S52 outside rearview mirror switch - terminal 5
   • S38 ignition mode switch - terminal 1
   • S58B rear compartment lid unlatch switch - interior - terminal 1
   • S79P window switch - passenger - terminal 1
   • If 5 Ω or greater 
   1. Ignition OFF.
   2. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
   • If less than 5 Ω 
3. Connect a test lamp between the appropriate control circuit terminal listed below and ground.
   • S30 headlamp switch - terminal 7
   • E37F dome/reading lamps - front - terminal 3
   • E1D accent lamp - driver door - terminal 1
   • E1P accent lamp - passenger door - terminal 1
   • E1Q accent lamp - console cupholder left - terminal 1
   • E1QS accent lamp - console cupholder right - terminal 1
   • S88 sunroof tilt switch - terminal 2
   • S72 sunroof switch - terminal 2
   • S13D door lock switch - driver- terminal 1
   • S13P door lock switch - passenger - terminal 1
   • S70R steering wheel controls switch - right - terminal 4
   • S70L steering wheel controls switch - left - terminal 6
   • S91 park brake control switch - terminal 6
   • S48A multifunction switch - instrument panel - terminal 8
   • S52 outside rearview mirror switch - terminal 10
   • S38 ignition mode switch - terminal 2
   • S58B rear compartment lid unlatch switch - interior - terminal 2
   • S79P window switch - passenger - terminal 2
4. Verify the test lamp turns ON and OFF when commanding the LED Backlight Dimming ON and OFF with a scan tool.
   • If the test lamp is always OFF 
   1. Ignition OFF, disconnect the appropriate harness connector at the K9 body control module.
   2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
   3. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 body control module.
   • If the test lamp is always ON 
   1. Ignition OFF, disconnect the appropriate harness connector at the K9 body control module, ignition ON.
   2. Test for less than 1 V between the control circuit terminal and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K9 body control module.
   • If the test lamp turns ON and OFF 
5. Test or replace the component with inoperative backlighting.

Passenger Air Bag Disable Indicator Backlighting Malfunction

1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the P14 passenger air bag disable indicator. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 5 Ω between the ground circuit terminal 3 and ground.
   • If 5 Ω or greater 
   1. Ignition OFF.
   2. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
   • If less than 5 Ω 
3. Connect a test lamp between the control circuit terminal 1 and ground.
4. Verify the test lamp turns ON and OFF while turning the ignition switch ON and OFF.
   • If the test lamp is always OFF 
   1. Ignition OFF, disconnect the X2 harness connector at the X50A fuse block - underhood.
   2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
   3. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the X50A fuse block - underhood.
   • If the test lamp is always ON 
   1. Ignition OFF, disconnect the X2 harness connector at the X50A fuse block - underhood, ignition ON.
   2. Test for less than 1 V between the control circuit terminal and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the X50A fuse block - underhood.
   • If the test lamp turns ON and OFF 
5. Test or replace the P14 passenger air bag disable indicator.