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.
Problems for specific Cadillac DeVille years:
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Most reported 1991 Cadillac DeVille problems
ABS Light Due to Control Module Failure
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.
58 Reports
Trunk Lid Won't Close Due to Trunk Pull Down Switch Failure
The trunk pull down switch may fail causing the trunk lid not to close completely. Our technicians tell us that the failed switch can be replaced without changing the complete pull down motor assembly.
54 Reports
Electronic Level Ride System May Fail
The electronic level ride system may not work properly; this may result in the rear of the vehicle riding too high or too low. Our technicians tell us that a height sensor or exhaust valve failure are common issues with this system. Proper diagnoses will be necessary to confirm the exact fault.
52 Reports
Car Won't Start and Security Light is On
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.
40 Reports
The Parking Brake May Not Automatically Release
The parking brake may not release automatically due to a failed vacuum switch or actuator. Our technicians tell us that if vacuum is supplied to the actuator when the transmission is in gear, the vacuum switch is functioning and replacing the actuator should correct this concern.
32 Reports
Transmission Fluid Leak From Cooler Line
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.
28 Reports
Air conditioning compressor may leak or become noisy
The air conditioning compressor may become noisy or develop a refrigeration leak, requiring replacement.
17 Reports
High Pressure Power Steering Hose Can Leak Fluid
The high-pressure power steering lines are known to leak.
15 Reports
Check Engine Light Due to Intake Manifold Vacuum Leaks
An intake manifold vacuum leak can develop from a variety of sources, often causing illumination of the Check Engine Light with codes P0171 & P0174 stored. Thorough diagnoses will be necessary to pinpoint the cause in order to make the correct repairs. A "smoke" machine is often used to isolate the cause of difficult to find vacuum leaks.
11 Reports
Check Engine Light due to EGR control solenoid/valve failure
The EGR control solenoid or EGR valve may fail causing the Check Engine Light to illuminate.
10 Reports
Fuel injectors can short-circuit
Fuel injectors can short-circuit electrically causing a rougher than normal idle and reduced performance.
10 Reports
Powertrain Control Module Electrical Ground Fault
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.
9 Reports
Noise and/or Dead Battery Due to failed Alternator
The alternator may fail causing the battery to go dead, or an abnormal noise may develop. The dash warning light may or may not illuminate. A failed alternator will require replacement.
9 Reports
Oil pressure switch/timing cover gasket may leak
The oil pressure switch and timing cover gasket may develop an engine oil leak.
8 Reports