P0353: Ignition Coil C Primary/Secondary Circuit Malfunction

What is P0353?

Error code P0353 is a generic Diagnostic Trouble Code (DTC) defined as “Ignition Coil C Primary/Secondary Circuit Malfunction.” 

The primary circuit is the wiring harness between your Silverado’s Engine Control Module (ECM) or Powertrain Control Module (PCM) to the ignition system. So, the circuit malfunction could mean anything from a shorted to a poorly grounded wire.

The secondary circuit refers to your spark plugs, plug wires, and ignition coils — specifically ignition coil C.

Many vehicles equipped with an OBD-II system use a coil-on-plug ignition system for an ignition spark. Using a coil-on-plug means these vehicles have an individual coil for each cylinder secured by a spark plug. 

The ignition coils are controlled by the ECM or PCM. A spark plug boot connects and insulates the high-voltage spark from the coil to the spark plug, acting like a spark plug wire. 

If the voltage reading in the ignition control circuit for ignition coil C (ignition coil number 3) varies by more than 10% from the allowed parameters, malfunction code P0353 is triggered.

Common symptoms

You may experience one or more of these common symptoms if your car has an active P0353 trouble code:

• Illuminated Check Engine Light
• Rough idling
• An engine misfire
• Decreased engine performance
• Increased fuel consumption
• A disabled fuel injector to the affected cylinder

Can I still drive?

Yes, you can still drive with an active P0353 diagnostic trouble code.

The driving abilities of your vehicle will likely remain unaffected by the error code. However, you should take your vehicle to a professional mechanic to have the error code fixed ASAP.

P0353 causes

These are the most common causes for fault code P0353:

• A damaged or defective ignition coil
• A corroded ignition coil connector
• Defective ignition coil driver circuit wiring
• A loose connection at the coil
• Broken connector locks
• A damaged camshaft sensor (CMP sensor) or crank sensor (CKP sensor)
• A defective ECM or PCM (which is rare)
• A vacuum leak in your engine intake manifold 
• Carbon buildup in the throttle body air passages

Diagnosis

Here’s how a mechanic will diagnose DTC P0353 to find the route cause of the problem:

• First, your mechanic will use a scan tool to check for any other trouble codes stored by your Engine Control Module or Powertrain Control Module.
• Then, they’ll inspect all ignition components related to ignition coil C for damage. These ignition components include your coil pack, spark plug wiring harness (if it uses one), ignition coil connector, and ignition coil circuit.
• To inspect ignition coil C itself, your mechanic will test the Hertz signal. If your Hertz reading is between 5 and 20, the coil is damaged.
• Your mechanic will then test the voltage of the coil driver circuit (COP driver circuit).
• Next, they’ll test the intake manifold for vacuum leaks.
• Finally, they’ll check for any damaged or defective camshaft or crankshaft sensors.

Possible repairs for P0353 & Costs

Since error code P0353 has so many possible causes, it’s important that your mechanic completes the diagnostic process entirely before moving on to any repairs.

You don’t want to pay for new camshaft sensors when a faulty spark plug wire is the actual cause — and end up paying more at the fuel pump while your P0353 error code is still active.

Here’s how a mechanic will fix the diagnostic trouble code P0353, depending on the underlying cause:

• Other error codes: Your mechanic will fix any other active error codes you may have in conjunction with P0353 in order of seriousness.
• Ignition coil: If your ignition coil is worn or defective, your mechanic will replace it with a new one.
• Ignition coil wires: If required, your mechanic will look at a wiring diagram and replace the ignition coil’s broken wire wires and wiring harness to ignition coil C. 
• Spark plug: Your mechanic will fit your vehicle with new spark plugs like a platinum or iridium spark plug — depending on what suits your engine. 
• Vacuum leak: Your mechanic will repair any form of vacuum leak you have. So, if you have a cracked vacuum line or a damaged intake manifold gasket, they’ll replace those parts for you.
• Camshaft sensor & crankshaft sensor: They’ll replace your camshaft sensor or crankshaft sensor if these parts are defective.
• ECM or PCM: A broken Engine Control Module or Powertrain Control Module is rarely the culprit for error code P0353. But, if these parts are damaged, your mechanic will try to reprogram them. If they’re damaged beyond repair, your mechanic will replace them with new ones.

Here’s an estimate of what you can expect to pay for a repair job, depending on the underlying issue:

• New ignition coil: $50-$110
• Camshaft sensor replacement: $119
• CKP sensor replacement: $135
• New PCM: $1000-$1200
• New ECM: $800-$1500
• Vacuum leak repair: $150-$1000

Note: The repair costs mentioned above include labor charges.