Circuit/System Testing
WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. However, it is still accessible from the selected car via links, so may be relevant.
Test 1
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the electrical connector: X1 & X2@S33 Horn Switch
- Test for less than 10 ohms between the test points: Ground circuit terminal 1 X2 & Ground
- If 10 ohms or greater
- Ground Connection - Disconnect
- 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
- Ignition - On / Vehicle - In Service Mode
- Verify the scan tool parameter: Horn Switch = Inactive
- If not the specified state
- Ignition/Vehicle - Off
- Disconnect the electrical connector: X3@K9 Body Control Module
- 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
- Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 1 X1 & Ground circuit terminal 1 X2
- Verify the scan tool parameter: Horn Switch = Active
- If not the specified state
- Ignition/Vehicle - Off & Remove - Jumper wire(s)
- Disconnect the electrical connector: X3@K9 Body Control Module
- Ignition - On / Vehicle - In Service Mode
- 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
- Ignition/Vehicle - Off
- 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
- Test or replace the component: S33 Horn Switch
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.
Test 2
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the electrical connector: P12 Horn
- Test for less than 1 ohms between the test points: Ground circuit terminal 1 & Ground
- If 1 ohms or greater
- Ground Connection - Disconnect
- 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
- Connect a test lamp between the test points: Control circuit terminal 2 & Ground circuit terminal 1
- Ignition - On / Vehicle - In Service Mode
- 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
- Go to next step: If the test lamp does not turn On and Off
- If the test lamp turns On and Off
- Ignition/Vehicle - Off
- Connect the electrical connector:P12 Horn
- Disconnect the electrical connector: X1@X50A Fuse Block - Underhood
- Ignition - On / Vehicle - In Service Mode
- Momentarily connect a 15 A fused jumper wire between the test points:Control circuit terminal 17 X1 & 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
- Ignition/Vehicle - Off & Remove - Jumper wire(s)
- Disconnect the electrical connector: P12 Horn
- Ignition - On / Vehicle - In Service Mode
- Test for less than 1 V between the test points: Control circuit terminal 17 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
- Ignition/Vehicle - Off
- Test for infinite resistance between the test points: Control circuit terminal 17 X1@Component harness & Ground
- If less than infinite resistance - Repair the short to ground on the circuit.
- Go to next step: If infinite resistance
- Test for less than 2 ohms between the test points: Control circuit terminal 2@Component harness & Control circuit terminal 17 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: P12 Horn
- Go to next step: If the component turns On and Off
- Connect the electrical connector: X1@X50A Fuse Block - Underhood
- Disconnect the electrical connector: X5@K9 Body Control Module
- Ignition - On / Vehicle - In Service Mode
- 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
- Ignition/Vehicle - Off & Remove - Jumper wire(s)
- Disconnect the electrical connector: X2X50A Fuse Block - Underhood
- Ignition - On / Vehicle - In Service Mode
- 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
- Ignition/Vehicle - Off
- 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
- Test for less than 2 ohms between the test points: Control circuit terminal 19 X5@Control module harness & Terminal 25 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
- Replace the component: K9 Body Control Module
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.
Test 3
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the electrical connector: P12 Horn
- Test for less than 1 ohms between the test points: Ground circuit terminal 1 & Ground
- If 1 ohms or greater
- Ground Connection - Disconnect
- 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
- Disconnect the electrical connector: X1@X50A Fuse Block - Underhood
- Test for less than 1 ohms between the test points: Control circuit terminal 2@Component harness & Control circuit terminal 17 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
- Test or replace the component: P12 Horn
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.