P0358 code definition
If the PCM (powertrain control module) fails to receive a valid pulse signal from ignition coil H, it will store a P0358 code and illuminate the Check Engine Light.
What the P0358 code means
The PCM continuously monitors the input signals from all of the engine’s ignition coils so that it can properly predict engine activity and provide the best strategies for ignition timing and fuel delivery. If an ignition coil is malfunctioning and/or is not sending the proper signal, the PCM will store this code because it is not getting the necessary information to perform these functions.
What causes the P0358 code?
A number of underlying problems can cause a P0358 code to be detected. These include:
- A defective ignition coil
- An open or shorted ignition coil circuit
- A poor electrical connection to the ignition coil
- A defective PCM (rare)
What are the symptoms of the P0358 code?
The only consistent symptom noted in all cases of a P0358 being detected is the illumination of the Check Engine Light. Other than this, you may also notice:
- Engine runs rough at idle
- Difficulty starting the engine
- Lack or loss of power when accelerating
- Engine hesitation when driving
How does a mechanic diagnose the P0358 code?
After using an OBD-II scanner to determine that a P0358 code has been stored, a mechanic will start by visually inspecting and examining the affected ignition coil, its circuits, wiring, and connections. If no obvious faults or damage are found, they will then swap the ignition coil pack with a good coil pack from another cylinder. They’ll then clear the code and retest the system. If the trouble code follows the coil pack to the new cylinder, then the ignition coil is the problem and should be replaced.
After completing all diagnostic steps and repairs, the mechanic will clear the code(s) again and take a test drive to determine whether or not the code has been thoroughly resolved.
Common mistakes when diagnosing the P0358 code
If the proper diagnostic steps aren’t taken, it is easy to assume that the ignition coil is to blame when it could be a loose electronic connection or another issue. With proper and thorough inspection of all possible causes, you can be sure that your repair(s) will actually fix the problem instead of wasting time and money.
How serious is the P0358 code?
The initial symptoms associated with a P0358 code may not be severe, but if the problem goes on long enough, it can result in engine pinging, engine knocking, and other problems. These can cause engine misfiring issues and other, more severe symptoms and issues that can do permanent engine damage and/or put you in a dangerous situation while driving.
What repairs can fix the P0358 code?
The right repair(s) will depend on what exactly is causing the PCM to detect and store the P0358 code. These include:
- Replacing the ignition coil
- Repairing a loose electrical connection to the ignition coil
- Replacing the wiring and/or connectors for the ignition coil circuit
- Replacing or reprogramming the PCM (rare)
Additional comments for consideration regarding the P0358 code
Whether or not your vehicle displays any or all of the symptoms listed above, it’s important to remember that to pass an OBD-II emissions test, your vehicle must not have any warning lights (including the Check Engine Light) illuminated. If you attempt to get an emissions test before resolving this issue, your vehicle will fail and you will have to get the issue resolved before paying to take it again.
Need help with a P0358 code?
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