1990 Cadillac Seville STS Problems
RepairPal has identified the most common problems with the 1990 Cadillac Seville STS based on complaints from actual vehicle owners. We'll tell you what the problem is and what it'll take to fix it.
Problems with 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 key and ignition lock cylinder should be replaced to correct this condition.
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.
One or more heater & AC (HVAC) temperature and/or air delivery mode door actuator may fail, resulting in improper temperature or air delivery. If this occurs, fault code(s) should be stored in the HVAC control module which should assist in diagnoses.
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.
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.
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.
The spark plugs should be replaced every 30,000 miles and the spark plug boots should be checked for hot spots and cracks.
The high-pressure power steering lines are known to leak.
It is common for the fuel level sensor in the fuel tank read the fuel level incorrectly. The sensor must be replaced to correct the condition. Our technicians recommend having the complete fuel pump module replaced on high mileage vehicles.
An automatic transmission fluid leak may develop from the rubber section of a transmission cooler line. In some cases the rubber section of hose can be replaced. In others, the complete cooler line must be replaced to correct this type of leak.
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.
Fuel injectors can short-circuit electrically causing a rougher than normal idle and reduced performance.
A coolant leak may develop from the water pump. This can result in an engine overheating condition. A leaking water pump will require replacement.