1. Preparation is Key:
* Safety First: Disconnect the negative battery cable before starting any work on the electrical system.
* Gather Tools and Parts: You'll need a socket set (metric), various wrenches, screwdrivers (Phillips and flathead), a transmission pan gasket, new transmission fluid (the correct type for your transmission – check your owner's manual), possibly a drain pan, jack stands, and of course, the correct replacement solenoid. A shop manual specific to your 1990 Corsica is highly recommended. It will have detailed diagrams and torque specifications.
* Vehicle Preparation: Raise the vehicle securely using jack stands. Consult your owner's manual for proper jacking points. Never work under a vehicle supported only by a jack.
2. Accessing the Transmission:
* Locate the Transmission Pan: The transmission pan is typically located on the bottom of the transmission. It's a fairly large, somewhat rectangular pan.
* Drain the Transmission Fluid: Carefully drain the transmission fluid into a suitable drain pan. Be prepared for several quarts of fluid – it will be hot! Allow ample time for complete drainage.
3. Removing the Transmission Pan:
* Remove the Transmission Pan Bolts: Carefully remove the bolts securing the transmission pan. These bolts are usually located around the perimeter of the pan. Keep track of the bolts and their location; some may be different lengths.
* Lower the Transmission Pan: Gently lower the transmission pan. Be careful, as there may still be some fluid inside. Some fluid will likely spill, so be prepared.
4. Locating and Replacing the Solenoid:
* Identify the Solenoid: Once the pan is removed, you'll see the solenoids mounted inside the valve body. The shop manual is crucial here to identify the correct solenoid. They are usually electrically connected and may be different sizes and shapes.
* Disconnect the Electrical Connector: Carefully disconnect the electrical connector from the faulty solenoid. Take a picture or make a note of how the connector is attached before disconnecting it to aid reassembly.
* Remove the Solenoid: The solenoid may be held in place with clips or screws. Carefully remove it.
* Install the New Solenoid: Install the new solenoid, ensuring it is properly seated and oriented.
* Reconnect the Electrical Connector: Reconnect the electrical connector.
5. Reassembly:
* Install the Transmission Pan: Carefully install the new transmission pan gasket (if replacing it, which is highly recommended). Then carefully lower the transmission pan into place and secure it with the bolts. Tighten the bolts to the manufacturer's specified torque (found in your shop manual).
* Refill the Transmission Fluid: Refill the transmission with the correct type and amount of transmission fluid. Consult your owner's manual for the proper fluid type and quantity.
* Check the Fluid Level: Check the transmission fluid level using the dipstick. The fluid level should be within the specified range.
6. Final Steps:
* Lower the Vehicle: Carefully lower the vehicle.
* Reconnect the Battery: Reconnect the negative battery cable.
* Test Drive: After refilling the transmission fluid, start the engine and check for any leaks. Then, test drive the vehicle to ensure the transmission is functioning correctly.
Important Considerations:
* Shop Manual: A shop manual is absolutely essential for this repair. It will provide detailed instructions, diagrams, and torque specifications.
* Transmission Type: The procedure might vary slightly depending on the type of automatic transmission in your Corsica (e.g., 3-speed, 4-speed).
* Professional Help: If you're not comfortable performing this repair yourself, it's best to take your vehicle to a qualified mechanic. Improper repair can lead to significant transmission damage.
This is a simplified overview. The actual process can be more involved and may require additional steps. Always consult a repair manual specific to your 1990 Chevrolet Corsica before attempting this repair. Safety should always be your top priority.
