This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.
P0358 is an OBD-II Code that refers to Ignition Coil H Primary/Secondary Circuit Malfunction
A P0358 code is caused by an ECM (Engine Control Module) receiving a signal from the PCM that the ignition coil is malfunctioning. If the signal is not sending when the engine is cranking, the code will be set.
Common causes for this code include:
- Defective Coils
- Open / Shorted Trigger or Cam Sensor
- Faulty Ignition Switch, Plug Wire or Coil Pack
- Short to Ground in the Coil's Primary Circuit (Power)
- Faulty PCM (Rare)
The symptoms of a P0358 code are:
- The Check Engine Light comes on
- Engine may be hard to start
- The engine may hesitate or stumble while running
- Power loss when you accelerate
To diagnose a P0358 DTC code, a technician would:
- Scan for codes in the ECM and look at the freeze frame data for failure.
- Check for signs of electrical shorts in the system by checking the ignition coil's primary wire and connector
- Look at any history codes and find out if one or more ignition coils have been replaced recently
- Check the power and ground circuits to each individual ignition coil, looking for a loss of power or ground.
- Check the ignition coil's resistance with a multimeter. If it has a higher or lower resistance than normal, then that may be the cause of the issue.
- If a coil is suspected, swap it out with a known working one and see if the problem follows it. This can help determine which coil(s) may be causing problems
The following are some of the most common mistakes that a technician may make when diagnosing a P0358 code:
- Not checking the freeze frame data for failure
- Not checking for signs of electrical shorts in the system by checking the ignition coil's primary wire and connector.
- Testing coils with a multimeter, but not testing each individual coil. Also, not knowing how to check them correctly
How serious is this?
A P0358 code is serious if the vehicle has an intermittent stalling or misfire problem. If the ignition coil(s) have failed and need replaced, it will be necessary to repair any electrical shorts that may occur as well. If the problem goes on long enough, it can result in engine pinging, engine knocking, and other problems but it can also cause damage to other components that may go undetected until much later down the road (if ever).
What repairs can fix the code?
The following are solutions that may fix this problem:
- Replacing the ignition coil(s)
- Repairing or replacing an electrical short in the system
- Wiring harness repair/replacement
- Replacing the PCM (rare)
A P0358 is related to and may be accompanied by the following codes:
In conclusion, the P0358 code is a generic trouble code that means the computer has detected an issue with the ignition coil and it is suggested that they be checked. If freeze frame data shows an incident where one or more coils failed, then those coils need to be replaced as well as any electrical shorts in the system.