Circuit/System Testing

WARNING: This page is about a different car, the 2020 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.

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.

Ignition/Vehicle & All vehicle systems - Off
Disconnect the appropriate electrical connector: M106 Exhaust Control Valve Actuator
Test for less than 10 ohms between the test points: Ground circuit terminal 1 & Ground
- If 10 ohms or greater
1. Disconnect the ground connection: Ground terminal
2. Test for less than 2 ohms between the test points: Ground circuit terminal 1 @ Component harness & The other end of the circuit @ Ground terminal
  - 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 a test lamp turns On between the test points: Ignition circuit terminal 3 & Ground
- If the test lamp does not turn On and the circuit fuse is OK
1. Ignition/Vehicle - Off & Remove - Test lamp
2. Test for less than 2 ohms between the test points: Ignition circuit terminal 3 & 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.
    Or
  - If less than 2 ohms - Refer to: Power Mode Mismatch
- If the test lamp does not turn On and the circuit fuse is open
1. Ignition/Vehicle - Off & Remove - Test lamp
2. Connect the electrical connector: M106 Exhaust Control Valve Actuator
3. Ignition - On / Vehicle - In Service Mode
4. Replace the component: Fuse
5. Verify the fuse does not open.
  - If the fuse opens and there are components connected to the circuit - Disconnect a component and repeat procedure starting at step 5.4
  - 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.
  NOTE:
  It may be necessary to use a scan tool control function to operate a component.
6. 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.
7. All OK.
- Go to next step: If the test lamp turns On
Test for 5.0 to 6.0 V between the test points: Control circuit terminal 2 & Ground circuit terminal 1
- If less than 5.0 V
1. Ignition/Vehicle - Off
2. Disconnect the electrical connector: K111 Fuel Pump Power Control Module
3. 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
4. Test for less than 2 ohms between the test points: Control circuit terminal 2 @ Component harness & The other end of the circuit @ Control module harness
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Replace the component: K111 Fuel Pump Power Control Module
- If greater than 6.0 V
1. Ignition/Vehicle - Off
2. Disconnect the electrical connector: K111 Fuel Pump Power Control Module
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.
  - If less than 1 V - Replace the component: K111 Fuel Pump Power Control Module
- Go to next step: If between 5.0 and 6.0 V
Test or replace the component: M106 Exhaust Control Valve Actuator