Circuit/System Verification

WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.

Ignition ON.

NOTE:

A low or high voltage DTC may set in multiple control modules due to a concern with the battery or charging system.

Verify there are no system voltage DTCs set as current or history in any control module.
- If any system voltage DTCs are set
  Diagnose these DTCs first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Go to next step: If no system voltage DTCs are set
Ignition Off and all vehicle systems OFF.

NOTE:

The battery voltage should stabilize after a few minutes of turning the ignition/vehicle Off.

Verify the battery voltage is within 12.4 V to 12.8 V at the C1 Battery.
- If not within the specified range
  Refer to Battery Inspection/Test
- Go to next step: If within the specified range
Engine Running with all accessories off, allow the system voltage to stabilize.
Test for 13 V to 15 V at the C1 Battery.
- If not within the specified value
  Refer to Charging System Test
- Go to next step: If within the specified range
Verify DTC U18A7, U18E2, P0615, P0616, P0617, P16D7, P16D8, or P16D9 are set as current.
- If any of the U18A7, U18E2, P0615, P0616, P0617, P16D7, P16D8, or P16D9 are set as current
  Diagnose these DTCs first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Go to next step: If DTC U18A7, U18E2, P0615, P0616, P0617, P16D7, P16D8, or P16D9 are not set as current
Refer to Circuit/System Testing.