Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Chevrolet >> 2018 >> Sonic Premier, 4D Hatchback, Automatic Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 280 (Lighting System) >> Diagnostic Information And Procedures >> DTC B2580 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2018 GMC Canyon and 2018 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the X5 harness connector at the K9 Body Control Module, ignition ON.
  2. Verify a test lamp illuminates between the control circuit terminal 18 and ground.
    • If the test lamp does 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 terminal 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 
  3. Ignition OFF, connect a 3 A fused jumper between the control circuit terminal 18 and ground.
  4. Verify the high beam headlamps illuminate.
    • If the high beam headlamps do not illuminate 
    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 18 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 high beam headlamps illuminate 
  5. Test or replace the K9 Body Control Module.
scientia non olet · About Mike's Workshop Manuals