Diagnostic Aids
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.
- A high or low voltage DTC set or voltage value in multiple modules/sensors indicates a concern in the 12 V charging system.
- A possible cause of this DTC could be overcharging with a 12 V battery charger or jump starting.
- The last 2 digits of the circuit number are significant in identifying its power and ground functions.
- Circuits ending in 42 are primary fused B+ circuits (generally the first fuse in the circuit after the battery)
- Circuits ending in 40 are secondary fused circuits (generally fuses in a fuse block after the primary circuit)
- Circuits ending in 39 and 41 are ignition voltage circuits.
- Circuits ending in 50 are grounds.
- Circuits ending in 51 are low reference (ground) circuits.