Circuit/System Testing
Turn Signal/Multifunction Switch Malfunction
- Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, open and close drivers door, disconnect the harness connector at the S78 Turn Signal/Multifunction Switch. It may take up to 2 min for all vehicle systems to power down.
- Test for less than 10 Ω between the ground circuit terminal 6 and ground.
- If 10 Ω or greater
- Ignition OFF.
- 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.
- Go to next step: If less than 10 Ω
- Ignition ON.
- Verify the scan tool Park Lamps Switch parameter is Inactive.
- If not Inactive
- Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module.
- Test for infinite resistance between the signal circuit terminal 7 and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance, replace the K9 Body Control Module.
- Go to next step: If Inactive
- Install a 3 A fused jumper wire between the signal circuit terminal 7 and ground.
- Verify the scan tool Park Lamps Switch parameter is Active.
- If not Active
- Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON.
- Test for less than 1 V between the signal circuit terminal 7 and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- Go to next step: If less than 1 V
- 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.
- Go to next step: If Active
- Test or replace the S78 Turn Signal/Multifunction Switch.
Park Lamps Malfunction
- Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON.
- Verify a test lamp illuminates between the B+ circuit terminal 2 and ground.
- If the test lamp does not illuminate and the circuit fuse is good
- Ignition OFF, remove the F18UA fuse at the X50A Fuse Block - Underhood.
- 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, verify the fuse is not open and there is voltage at the fuse.
- If the test lamp does not illuminate and the circuit fuse is open
- Ignition OFF, remove the F18UA fuse at the X50A Fuse Block - Underhood.
- 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, replace the K9 Body Control Module.
- Go to next step: If the test lamp illuminates
- Ignition OFF, connect the X1 harness connector at the K9 Body Control Module.
- Ignition OFF, exterior lamps OFF, disconnect the harness connector at the appropriate component listed below. It may take up to 2 min for all vehicle systems to power down.
- E2LF Side Marker Lamp - Left Front
- E2LR Side Marker Lamp - Left Rear
- E5E Tail Lamp - Left (without T4F)
- E42L Tail Lamp Assembly - Left (with T4F)
- E2RF Side Marker Lamp - Right Front
- E2RR Side Marker Lamp - Right Rear
- E5F Tail Lamp - Right (without T4F)
- E42R Tail Lamp Assembly - Right (with T4F)
- Test for less than 5 Ω between the appropriate ground circuit terminal listed below and ground.
- E2LF Side Marker Lamp - Left Front terminal 1
- E2LR Side Marker Lamp - Left Rear terminal 1
- E5E Tail Lamp - Left socket terminal (without T4F)
- E42L Tail Lamp Assembly - Left terminal 6 (with T4F)
- E2RF Side Marker Lamp - Right Front terminal 1
- E2RR Side Marker Lamp - Right Rear terminal 1
- E5F Tail Lamp - Right socket terminal (without T4F)
- E42R Tail Lamp Assembly - Right terminal 6 (with T4F)
- If 5 Ω or greater
- Ignition OFF.
- 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.
- Go to next step: If less than 5 Ω
- Connect a test lamp between the appropriate control circuit terminal listed below and ground, ignition ON.
- E2LF Side Marker Lamp - Left Front terminal 2
- E2LR Side Marker Lamp - Left Rear terminal 2
- E5E Tail Lamp - Left socket terminal (without T4F)
- E42L Tail Lamp Assembly - Left terminal 5 (with T4F)
- E2RF Side Marker Lamp - Right Front terminal 1
- E2RR Side Marker Lamp - Right Rear terminal 1
- E5F Tail Lamp - Right socket terminal (without T4F)
- E42R Tail Lamp Assembly - Right terminal 5 (with T4F)
- Verify the test lamp turns ON and OFF when commanding the appropriate Front Park Lamp ON and OFF with a scan tool.
- If the test lamp is always OFF
- Ignition OFF, disconnect the appropriate harness connector listed below at the K9 Body Control Module.
- X4 - left park lamps
- X5 - right park lamps
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- Go to next step: If infinite resistance
- 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
- Ignition OFF, disconnect the appropriate harness connector listed below at the K9 Body Control Module, ignition ON.
- X4 - left park lamps
- X5 - right park lamps
- 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.
- Go to next step: If the test lamp turns ON and OFF
- Test or replace the park/marker lamp.
License Plate Lamps Malfunction
- Ignition OFF, exterior lamps OFF, remove both E7 License Plate Lamps. It may take up to 2 min for all vehicle systems to power down. It may take up to 2 min for all vehicle systems to power down.
- Test for less than 5 Ω between the ground circuit terminal 2 and ground.
- If 5 Ω or greater
- Ignition OFF.
- 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.
- Go to next step: If less than 5 Ω
- Connect a test lamp between the E7L License Plate Lamp - Left control circuit terminal 1 and ground, ignition ON.
- Verify the test lamp turns ON and OFF when commanding the License Plate Lamps ON and OFF with a scan tool.
- If the test lamp is always OFF
- Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- Go to next step: If infinite resistance
- 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
- Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module, ignition ON.
- 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.
- Go to next step: If the test lamp turns ON and OFF
- Connect a test lamp between the E7R License Plate Lamp - Right control circuit terminal 1 and ground, ignition ON.
- Verify the test lamp turns ON and OFF when commanding the License Plate Lamps ON and OFF with a scan tool.
- If the test lamp is always OFF
- Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- Go to next step: If infinite resistance
- 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.
- Go to next step: If the test lamp turns ON and OFF
- Test or replace the E7 License Plate Lamp.