What Does the P0355 Code Mean?
The P0355 code is a diagnostic trouble code (DTC) that indicates a malfunction in the ignition coil “E” primary or secondary circuit. This code signifies that the vehicle’s Powertrain Control Module (PCM) has detected an electrical issue affecting the ignition coil’s operation.
What Causes the P0355 Code?
Several factors can trigger the P0355 code:
- Defective Ignition Coil(s)
- Defective Spark Plug(s)
- Intake Manifold Vacuum Leaks
- Carbon Buildup in the Throttle Body Air Passages
- Defective Idle Air Control Valve or Electronic Throttle Body
What Are the Symptoms of the P0355 Code?
Common symptoms associated with the P0355 code include:
- Check Engine Light will illuminate
- Engine idles roughly
- Engine misfires on acceleration
- In rare cases, the engine may not exhibit noticeable symptoms
How Serious Is the P0355 Code?
The P0355 code is considered urgent and should be addressed immediately. Ignoring this code can lead to severe damage to the vehicle’s engine and may pose safety risks to the driver and passengers.
How to Diagnose the P0355 Code
To accurately diagnose the P0355 code, follow these steps:
- Record the freeze frame data and conditions under which the code was triggered.
- Perform a test drive while monitoring engine load, throttle position, RPM, and road speed.
- Use a data streaming scanner to check for misfire PID information.
- Verify the steadiness of the crank signal.
- If applicable, switch the entire coil and spark plug assembly with a known good cylinder and retest.
- Conduct a compression test on any offending cylinder and check for vacuum leaks.
- Inspect the connectors and wiring for the ignition coil circuit.
- If necessary, test the coil firing signal using a labscope.
Common Repairs for the P0355 Code
Common repairs that may resolve the P0355 code include:
- Replacing defective ignition coils
- Replacing worn or damaged spark plugs
- Repairing vacuum leaks in the intake manifold
- Cleaning carbon buildup in the throttle body
- Replacing faulty sensors or control components associated with the ignition system
How Much Does It Cost to Fix the P0355 Code?
The cost to fix the P0355 code can vary based on the underlying issue. On average, repairs can range from $100 to $500, depending on whether parts need to be replaced or if additional diagnostics are required.
Can I Fix the P0355 Code Myself?
While some experienced DIYers may be able to address the P0355 code themselves, it is crucial to have a thorough understanding of automotive diagnostics and repair. If you are unsure or lack the necessary tools, it is best to seek professional assistance to avoid further complications.
