How to Test and Fix a Faulty Ignition Cassette
Many cars nowadays use a direct ignition cassette that contains the ignition coils that connects directly to the spark plugs. This is why once the vehicle starts to have ignition-related problems, one of the likely culprits is a faulty ignition cassette.
Diagnosing and fixing ignition cassette problems can be tricky especially for beginners, but it is quite possible. In this guide, we will show you how to test the ignition cassette.
Difficulty level: Moderate
What you'll need:
- Flathead screwdriver
- Socket wrench with spark plug attachment
- Anti-seize compound
- Clean rag
Step 1: Set the car to park and switch off the ignition. Wait until at least an hour before starting to allow any high voltage current that's potentially stored in the direct ignition system.
Step 2: Locate the ignition cassette. Refer to the car's operating manual or service manual to determine its exact location. In most cases, the cassette is located somewhere on top of the engine block next to the engine control module.
Step 3: Wipe the cover of the ignition cassette with a rag. This will prevent dust and debris from entering the cassette once it is opened.
Step 4: Disconnect the cable connecting the ignition cassette to the engine control subsystem. To do this, you will need to pry out the tab on the side of the cable and slowly pull the cable out from its mounting.
Step 5: Loosen the screws securing the ignition cassette in place then detach the cassette itself. When removing the cassette, make sure to pull away from the engine to prevent damaging any nearby parts and electrical wiring.
Step 6: Turn the cassette over. Ground each plug to the negative battery terminal and switch on the engine. If the cassette is working properly, there should be sparks running along the length of the plugs several times. But if one or more of the plugs have no spark or a very weak spark, the cassette is the cause of the malfunction and has to be replaced. Switch off the engine afterwards and wait for another hour before handling the cassette again.
Note: be sure to be at a safe distance away from the cassette when the ignition is switched on to prevent electric shock.
Step 7: Check the areas around the spark plug and around the general area the coils for oil residue. Oil residue around these areas means that oil is leaking from the engine to the cassette.
Step 8: Unscrew the spark plugs from the cassette with a socket wrench using a spark plug remover attachment. Remove only one spark plug at a time to prevent confusion as well as accidental damage to the plugs.
Step 9: Inspect the condition of the spark plugs and gap them as necessary. If the spark plugs appear burnt or melted, we recommend replacing them with new ones.
Step 10: Apply anti-seizing compound on the threads of the spark plug holes on the cassette then screw the plugs back into place.
Step 11: Once they are in place, add dielectric compound to the tips of the spark plugs. You can also apply the compound before installing the plugs, but it is highly likely that the compound will get smeared.
Step 12: Reattach the ignition cassette and its cable to the engine control subsystem.