Anybody encounter this before??? My truck was running good for a while then started mis-firing again so I change the plugs and 2 coils and now it's missing worse than before . I know it has to do with the circuit or something.

 

What is the Circuit like?

• A ground for the electronic spark timing 3 circuit is enabled by the engine control module (ECM).
• The magnetic field created by the coil collapses when the ECM removes the ground path of the ignition primary coil.
• This dying magnetic field generates a voltage in the secondary coil which shoots the spark plug.
• A close monitoring is done to the circuit between the ECM and the electronic ignition system for an open circuit, short to voltage, and low voltage.
• DTC PO353 is introduced the moment the ECM sniffs a problem in the spark timing 3 circuit.

Look for a flawed connection or a damaged terminal 3 at the ignition coil.

 

Got it figured out.

 

what was the problem i have a 2003 f150 that idle fine but when it is under a load it has a bad misfire and dtc is the same as yours