Most reported 1993 Cadillac DeVille problems

One or more heater & AC (HVAC) air delivery and/or temperature mode door actuator may fail. This can result in incorrect air delivery or temperature. If this occurs, fault code(s) stored in the HVAC control module should be available to assist with diagnoses.

The anti-lock brake system (ABS) control module may fail causing the ABS light to illuminate. Failed modules should be replaced to restore ABS operation.

Problems with the anti-theft systems using the raised-chip key can prevent the car from starting. The wires in the steering column to the ignition lock cylinder tend to break. The the key and ignition lock cylinder must be replaced to correct this condition.

The rubber section of an automatic transmission cooler line may develop a fluid leak . In some cases the leaking section of hose can be replaced. In others, the complete cooler line must be replaced to correct this concern.

The high-pressure power steering lines are known to leak.

Fuel injectors can short-circuit electrically causing a rougher than normal idle and reduced performance.

An updated PROM (Programmable Read Only Memory) chip may be available for the powertrain control module (PCM). Check with your dealer.

This powertrain control module (PCM) may develop a fault with its electrical ground location at the front of the engine block near the starter motor.