Can a bad ignition coil still pass the test?
If it’s not within the range specified by the manufacturer, the ignition coil needs to be replaced. However, it’s possible for bad coils to still pass this test. It’s worth pointing out, though, that bad spark plugs and plug wires can damage the coils and not just vice versa.
How do you test a spark plug ignition coil?
If necessary, remove any plastic covers that may be covering the ignition coils. Step 3: Disconnect the wiring harness for the ignition coils. Remove them using your hand tools. Ignition coils are usually very simple to remove, often times only held in by one or two bolts. Step 4: Test the ignition coil’s primary ignition circuit.
What does a zero reading on ignition coil mean?
If a reading of zero is displayed, that signifies that the ignition coil has shorted internally in the primary windings and needs to be replaced. A reading over the specification signals that the ignition coil is open, which would also indicate a need to replace the coil. Step 5: Test the secondary circuit of the ignition coil.
What should the resistance of an ignition coil be?
Most ignition coils should have a primary resistance falling somewhere between 0.4 and 2 ohms; however, refer to your manufacturer’s specifications for the correct reading. If a reading of zero is displayed, that signifies that the ignition coil has shorted internally in the primary windings and needs to be replaced.
How to test a coil pack or ignition coil?
1. How to Test an Ignition Coil on a Modern Car: 6 Different Methods 1.1. Perform a Visual Inspection 1.2. Swap the Suspect Ignition Coil to Another Cylinder 1.3. Use a Spark Tester 1.4. Use a Coil-on-Plug (COP) Probe 1.5. Check the Resistance of the Ignition Coil 1.6. Monitor the Ignition Pattern with an Oscilloscope 2.
What causes an ignition coil to go bad?
Either one of these windings can go bad and cause your ignition coil to fail. Sometimes an ignition coil is clearly bad because it makes no spark at all. But if a coil is only on its way out and not yet dead, it can make a weak spark that will make your car run poorly.
Can a bad coil pass a resistance test?
Since you’re not monitoring the coil when it’s hot or under load, it’s possible for a bad coil to pass a resistance test. What’s more, fewer automakers are listing coil resistance specifications in their repair information. Still, in some instances, the test can prove useful.
If a reading of zero is displayed, that signifies that the ignition coil has shorted internally in the primary windings and needs to be replaced. A reading over the specification signals that the ignition coil is open, which would also indicate a need to replace the coil. Step 5: Test the secondary circuit of the ignition coil.