Tools You'll Need:
* Socket wrench set (metric)
* Ratchet
* Extension(s)
* Possibly a swivel socket adapter for easier access
* Screwdrivers (Phillips and possibly flathead)
* Wire brush (optional, for cleaning terminals)
* Electrical grease (optional, for new connections)
* New ICM (ensure you get the correct part number for your vehicle)
* Safety glasses
* Gloves
Steps:
1. Disconnect the Battery: This is CRUCIAL to prevent electrical shock and damage to your vehicle's electrical system. Disconnect the negative (-) terminal first, then the positive (+).
2. Locate the ICM: The ICM's location varies slightly depending on the engine. It's usually mounted on or near the distributor, often on the firewall or the intake manifold. Consult your repair manual for the precise location.
3. Disconnect Electrical Connectors: Carefully unplug any electrical connectors attached to the ICM. Take note of their position for reassembly. A small camera can be useful here to take pictures before disconnecting.
4. Remove Mounting Bolts/Fasteners: The ICM is usually held in place by one or two bolts or screws. Remove these carefully.
5. Remove the Old ICM: Gently pull the old ICM out of its mounting bracket.
6. Clean the Mounting Surface and Terminals: Use a wire brush to clean any corrosion or debris from the mounting surface and the electrical terminals on both the ICM and its connector.
7. Install the New ICM: Carefully align the new ICM with its mounting bracket and install the bolts/screws, tightening them securely.
8. Reconnect Electrical Connectors: Plug in the electrical connectors, making sure they are securely seated.
9. Reconnect the Battery: Reconnect the positive (+) terminal first, then the negative (-) terminal.
10. Test the Vehicle: Start the engine and check for smooth operation. Listen for any unusual noises. Test the engine at different RPMs to ensure the ignition is firing correctly.
Important Considerations:
* Part Number: Get the correct ICM part number for your specific vehicle. Providing your engine size (e.g., 3.1L V6) will help when ordering the part.
* Repair Manual: A repair manual specific to your 1990 Oldsmobile Cutlass Supreme is highly recommended. It will provide detailed diagrams and instructions.
* Safety: Always disconnect the battery before working on any electrical components.
* Professional Help: If you are not comfortable performing this repair yourself, take your vehicle to a qualified mechanic.
This is a general guide. Always prioritize safety and consult your vehicle's service manual for specific instructions tailored to your model. Improper installation could lead to further vehicle damage.
