Circuit/System Testing

Ignition OFF, exterior lamps OFF, disconnect the harness connector at the appropriate E13 Headlamp Assembly. It may take up to 2 min for all vehicle systems to power down.
Test for less than 15 Ω between the ground circuit terminal 9 and ground.
- If 15 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.
- Go to next step: If less than 15 Ω
Ignition ON.
Verify a test lamp illuminates between the B+ circuit terminal 5 and ground.
- If the test lamp does not illuminate
1. Ignition OFF, disconnect the X1 harness connector at the X50A Fuse Block - Underhood.
2. Test for infinite resistance between the B+ circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - Go to next step: 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.
- Go to next step: If the test lamp illuminates
Test or replace the K28 Headlamp Leveling Control Module.
Ignition ON.
Verify the appropriate headlamp operates to the LEFT and RIGHT positions when commanding the appropriate Headlamp Horizontal Motor LEFT and RIGHT with a scan tool.
- If the headlamp does not operate LEFT and RIGHT
- Test or replace the E13 Headlamp Assembly.
- Go to next step: If the headlamp operates LEFT and RIGHT
All OK.