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Home >> Chevrolet >> 2019 >> Sonic LS, Automatic Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 44 (Lighting System) >> Diagnostic Information And Procedures >> DTC B259A >> Circuit/System Testing
July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

Circuit/System Testing

WARNING: This page is about a different car, the 2018 Chevrolet Sonic. However, it is still accessible from the selected car via links, so may be relevant.
  1. 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.
  2. Test for less than 10 Ω between the ground circuit terminal 1 and ground.
    • If 10 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 10 Ω 
  3. Connect the harness connector at the E13 Headlamp Assembly.
  4. Disconnect the X2 harness connector at the X50A Fuse Block - Underhood.
  5. Test for less than 10 Ω between the appropriate ground circuit terminal listed below and ground.
    • Terminal G3 - left daytime running lamp
    • Terminal D9 - right daytime running lamp
    • If 10 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 10 Ω 
  6. Disconnect the X1 harness connector at the X50A Fuse Block - Underhood.
  7. Connect a 3 A fused jumper between the appropriate control circuit terminal listed below and B+.
    • Terminal H1 - left daytime running lamp
    • Terminal G2 - right daytime running lamp
  8. Verify the E4 Daytime Running Lamp illuminates.
    • If the daytime running lamp does not illuminate 
    1. Ignition OFF, disconnect the harness connector at the E13 Headlamp Assembly.
    2. 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
    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 E13 Headlamp Assembly.
    • Go to next step: If the daytime running lamp illuminates 
  9. Ignition OFF, connect the X1 harness connector at the X50A Fuse Block - Underhood.
  10. Disconnect the X5 harness connector at the K9 Body Control Module, ignition ON
  11. Verify a test lamp does not illuminate between the control circuit terminal 11 and ground.
    • If the test lamp illuminates 
    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.
    • Go to next step: If the test lamp does not illuminate 
  12. Ignition OFF, connect a 3 A fused jumper between the control circuit terminal 11 and B+, ignition ON.
  13. Verify both daytime running lamps illuminate.
    • If the daytime running lamps do not illuminate 
    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.
      • 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 daytime running lamps illuminate 
  14. Test or replace the K9 Body Control Module.