Circuit/System Testing
WARNING: This page is about a different car, the 2022 Cadillac CT5. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition Service Mode
- Verify there are no other DTCs set, except for DTC P156D.
- If any other DTCs are set
- Go to next step: If only DTC P156D is set
- Replace the T19 Multifunction Power Supply Converter
- Verify the DTC does not set.
- If the DTC Sets Replace the K20 Engine Control Module
- Go to next step: If the DTC does not set
- A fault is not currently present and may be an intermittent condition.