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:P12B Horn - Low Note
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:P12B Horn - Low Note

   • Go to next step: If the test lamp does not turn On and Off 
7. Ignition/Vehicle - Off
8. Connect the electrical connector:P12B Horn - Low Note
9. Disconnect the electrical connector:X1 @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 D4 X1 & B+

    Verify the component turns On and Off when connecting and disconnecting the jumper wire: P12B Horn - Low Note

    • If the component does not turn On and Off 
    1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
    2. Disconnect the electrical connector:P12B Horn - Low Note
    3. Ignition - On / Vehicle - In Service Mode
    4. Test for less than 1 V between the test points:Control circuit terminal D4 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 infinite resistance between the test points:Control circuit terminal D4 X1 @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 D4 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:P12B Horn - Low Note
    • Go to next step: If the component turns On and Off 
12. Connect the electrical connector:X1 @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:P12B Horn - Low Note

    • If the component does not turn On and Off 
    1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
    2. Disconnect the electrical connector:X2 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 G10 X2 @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: P12B Horn - Low Note
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:X1 @X50A Fuse Block - Underhood
5. Test for less than 1 ohms between the test points:Control circuit terminal 2 @Component harness & Control circuit terminal D4 X1 @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: P12B Horn - Low Note