Q: The trigger wire for ignition coil three has no signal.

asked by on March 30, 2018

I have bought new crank sensor. But my problem is when I turn the key halfway I get 12 volts, a ground, and .02 volts in all trigger wires except cylinder number 3 ?? Could it be cam sensors ? I don't even have to start it to see I get nothing only from that trigger wire. What should I do what could it be??

My car has 180000 miles.
My car has an automatic transmission.

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The coil in your application has a power wire (red), a ground wire (black), and a PCM pulse command wire (5 volt pulse; Blue w/Red stripe for cylinder No. 3) that operates the coil’s internal switching transistor. Using an oscilloscope, if there is no signal on the blue w/red stripe pulse (trigger) wire, first check the circuit integrity on that wire back to the PCM. If the circuit is intact (no voltage drop, not just a measure for continuity), the coil driver within the PCM may be faulty. If you desire a diagnostic, and repair, the relevant service to request is an electrical component/circuit diagnostic. If you request that service, the responding certified mechanic will get this diagnosed and resolved, right at your location. If you have further questions or concerns, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the best possible results.

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