LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2018 >> Spark LT, Automatic CVT Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 97 (Horn System) >> Diagnostic Information and Procedures >> Horns Malfunction >> Circuit/System Testing >> Test 2

Test 2

WARNING: This page is about a different car, the 2017 Chevrolet Spark. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition/Vehicle & All vehicle systems - Off
    NOTE: It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.
  2. Disconnect the electrical connector: P12 Horn
  3. Test for less than 1 Ω between the test points: Ground circuit terminal 1 & Ground
    • If 1 Ω or greater 
    1. Ground Connection - Disconnect
    2. Test for less than 1 Ω between the test points: Ground circuit terminal 1 & Ground Connection
      • If 1 Ω or greater - Repair the open/high resistance in the circuit.
    • If less than 1 Ω 
  4. Connect a test lamp between the test points: Control circuit terminal 2 & Ground circuit terminal 1
  5. Ignition - On / Vehicle - In Service Mode
  6. Perform the scan tool control function: Horn Relay Command - On and Off

    Verify the test lamp does not turn On and Off.

    • If the test lamp turns On and Off 

      Test or replace the component: P12 Horn

    • If the test lamp does not turn On and Off 
  7. Ignition/Vehicle - Off
  8. Connect the electrical connector: P12 Horn
  9. Disconnect the electrical connector: X2 @ X50A Fuse Block - Underhood
  10. Ignition - On / Vehicle - In Service Mode
  11. Momentarily connect a 15 A fused jumper wire between the test points: Control circuit terminal 17 X2 & B+

    Verify the component turns On and Off when connecting and disconnecting the jumper wire: P12 Horn

    • If the component does not turn On and Off 
    1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
    2. Disconnect the electrical connector: P12 Horn
    3. Ignition - On / Vehicle - In Service Mode
    4. Test for less than 1 V between the test points: Control circuit terminal 1 @ P12 Horn & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • If less than 1 V
    5. Ignition/Vehicle - Off
    6. Test for infinite resistance between the test points: Control circuit terminal 1 @ P12 Horn & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance
    7. Test for less than 2 Ω between the test points: Control circuit terminal 1 @ P12 Horn & Control circuit terminal 17 X2 @ Fuse Block Harness
      • If 2 Ω or greater - Repair the open/high resistance in the circuit.
      • If less than 2 Ω - Test or replace the component: P12 Horn
    • If the component turns On and Off 
  12. Connect the electrical connector: X2 @ X50A Fuse Block - Underhood
  13. Disconnect the electrical connector: X5 @ K9 Body Control Module
  14. Ignition - On / Vehicle - In Service Mode
  15. Momentarily connect a 3 A fused jumper wire between the test points: Control circuit terminal 19 X5 & B+

    Verify the component turns On and Off when connecting and disconnecting the jumper wire: P12 Horn

    • If the component does not turn On and Off 
    1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
    2. Disconnect the electrical connector: X1 @ X50A Fuse Block - Underhood
    3. Ignition - On / Vehicle - In Service Mode
    4. Test for less than 1 V between the test points: Control circuit terminal 19 X5 @ Control module harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • If less than 1 V
    5. Ignition/Vehicle - Off
    6. Test for infinite resistance between the test points: Control circuit terminal 19 X5 @ Control module harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance
    7. Test for less than 2 Ω between the test points: Control circuit terminal 19 X5 @ Control module harness & Terminal 21 X1 @ Fuse Block Harness
      • If 2 Ω or greater - Repair the open/high resistance in the circuit.
      • If less than 2 Ω - Test or replace the component: X50A Fuse Block - Underhood
    • If the component turns On and Off 
  16. Replace the component: K9 Body Control Module