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Circuit/System Testing

Test 1

    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.

  1. Ignition/Vehicle & All vehicle systems - Off
  2. Disconnect the electrical connector: X1 & X2@S33 Horn Switch
  3. Test for less than 10 ohms between the test points: Ground circuit terminal 1 X2 & Ground
    • If 10 ohms or greater 
    1. Ground Connection - Disconnect
    2. Test for less than 2 ohms between the test points: Ground circuit terminal 1 X2@Component harness & Ground Connection
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Repair the open/high resistance in the ground connection.
    • Go to next step: If less than 10 ohms 
  4. Ignition - On / Vehicle - In Service Mode
  5. Verify the scan tool parameter: Horn Switch = Inactive
    • If not the specified state 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector: X3@K9 Body Control Module
    3. Test for infinite resistance between the test points: Signal circuit terminal 1 X1@Component harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Replace the component: K9 Body Control Module
    • Go to next step: If the specified state 
  6. Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 1 X1 & Ground circuit terminal 1 X2
  7. Verify the scan tool parameter: Horn Switch = Active
    • If not the specified state 
    1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
    2. Disconnect the electrical connector: X3@K9 Body Control Module
    3. Ignition On/Vehicle in Service Mode.
    4. Test for less than 1 V between the test points: Signal circuit terminal 1 X1@Component harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • Go to next step: If less than 1 V
    5. Ignition/Vehicle - Off
    6. Test for less than 2 ohms between the test points: Signal circuit terminal 1 X1@Component harness & Terminal 18 X3@Control module harness
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Replace the component: K9 Body Control Module
    • Go to next step: If the specified state 
  8. Test or replace the component: S33 Horn Switch

Test 2

    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.

  1. Ignition/Vehicle & All vehicle systems - Off
  2. Disconnect the electrical connector: P13 Horn Assembly
  3. Test for less than 1 ohms between the test points: Ground circuit terminal 1 & Ground
    • If 1 ohms or greater 
    1. Ground Connection - Disconnect
    2. Test for less than 1 ohms between the test points: Ground circuit terminal 1 & Ground Connection
      • If 1 ohms or greater - Repair the open/high resistance in the circuit.
    • Go to next step: If less than 1 ohms 
  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: P13 Horn Assembly

    • Go to next step: If the test lamp does not turn On and Off 
  7. Ignition/Vehicle - Off
  8. Connect the electrical connector: P13 Horn Assembly
  9. Disconnect the electrical connector: X5@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 28 X5 & B+

    Verify the component turns On and Off when connecting and disconnecting the jumper wire: P13 Horn Assembly

    • If the component does not turn On and Off 
    1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
    2. Disconnect the electrical connector: P13 Horn Assembly
    3. Ignition - On / Vehicle - In Service Mode
    4. Test for less than 1 V between the test points: Control circuit terminal 2@Component harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • Go to next step: If less than 1 V
    5. Ignition/Vehicle - Off
    6. Test for infinite resistance between the test points: Control circuit terminal 2@Component harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    7. Test for less than 2 ohms between the test points: Control circuit terminal 2@Component harness & Control circuit terminal 28 X5@Fuse Block Harness
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Test or replace the component: P13 Horn Assembly
    • Go to next step: If the component turns On and Off 
  12. Connect the electrical connector: X5@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: P13 Horn Assembly

    • 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.
      • Go to next step: 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.
      • Go to next step: If infinite resistance
    7. Test for less than 2 ohms between the test points: Control circuit terminal 19 X5@Control module harness & Terminal 9 X1@Fuse Block Harness
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Test or replace the component: X50A Fuse Block - Underhood
    • Go to next step: If the component turns On and Off 
  16. Replace the component: K9 Body Control Module

Test 3

    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.

  1. Ignition/Vehicle & All vehicle systems - Off
  2. Disconnect the electrical connector: P13 Horn Assembly
  3. Test for less than 1 ohms between the test points: Ground circuit terminal 1 & Ground
    • If 1 ohms or greater 
    1. Ground Connection - Disconnect
    2. Test for less than 1 ohms between the test points: Ground circuit terminal 1 & Ground Connection
      • If 1 ohms or greater - Repair the open/high resistance in the circuit.
    • Go to next step: If less than 1 ohms 
  4. Disconnect the electrical connector: X5@X50A Fuse Block - Underhood
  5. Test for less than 1 ohms between the test points: Control circuit terminal 2@Component harness & Control circuit terminal 28 X5@Fuse Block Harness
    • If 1 ohms or greater - Repair the open/high resistance in the circuit.
    • Go to next step: If less than 1 ohms 
  6. Test or replace the component: P13 Horn Assembly
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