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.
- Ignition/Vehicle - Off
- Disconnect the electrical connector:X1@K20 Engine Control Module
- Connect a 3 A fused jumper wire between the test points: Control circuit terminal 67 & Ground
- Ignition - On / Vehicle - In Service Mode
- Verify a test lamp turns On between the test points: Ignition circuit terminal 51 & Ground
- If the test lamp does not turn On and the circuit fuse is OK
- Ignition/Vehicle - Off & Remove - Test lamp
- Test for less than 2 ohms between the test points: Ignition circuit terminal 51@Control module harness & Output terminal@Fuse
- If 2 ohms or greater - Repair the open/high resistance in the circuit.
- If less than 2 ohms - Verify the fuse is OK and there is voltage at the fuse.
- If the test lamp does not turn On and the circuit fuse is open
- Ignition/Vehicle - Off
- Replace the component:F03UA Fuse
- Ignition - On / Vehicle - In Service Mode
- Verify the fuse does not open.
- If the fuse opens and there are components connected to the circuit - Disconnect a component and repeat step 5.1
- If the fuse opens with all components disconnected from the circuit - Repair the short to ground on the circuit.
- If the fuse does not open after disconnecting a component from the circuit - Replace the component disconnected last.
- Go to next step: If the fuse does not open with all components connected, except the following component: K20 Engine Control Module
- Ignition/Vehicle - Off
- Connect the electrical connector: K20 Engine Control Module
- Replace the component: F03UA Fuse
- Ignition - On / Vehicle - In Service Mode
- Verify the fuse does not open.
- If the fuse is open - Replace the component: K20 Engine Control Module
- Go to next step: If the fuse does not open.
- Operate the component: Each component on the circuit - One at a time
Verify the fuse does not open when any of the components are activated.
- If the fuse opens - Replace the component that caused the fuse to open when activated.
- Go to next step: If the fuse does not open.
- All OK.
NOTE:It may be necessary to use a scan tool control function to operate a component.
- Go to next step: If the test lamp turns On
- Replace the component: K20 Engine Control Module