P0358 indicates that the powertrain control module (PCM) has detected an open circuit in the primary control circuit for ignition coil H (typically cylinder 8). This means the PCM is not seeing the expected voltage/current flow when it tries to energize the coil, which can prevent proper spark generation for that cylinder.
The internal primary winding of coil H has broken, creating an open circuit that the PCM detects as a lack of current flow.
A broken wire, chafed insulation, or corroded connector in the harness between the PCM and coil H prevents proper signal transmission.
Poor contact in the coil or PCM connector can increase resistance to the point where the PCM interprets it as an open circuit.
If the fuse/relay that powers the coil driver stage is open, the PCM will see no current when commanding the coil.
The transistor or driver inside the PCM that controls coil H can fail, but this is uncommon and should be considered only after wiring and coil checks.
A bad ground connection for the PCM can cause erratic driver behavior, appearing as an open circuit on a specific coil.
PCM failure is a rare cause of P0358. Most cases are due to a faulty ignition coil, wiring, or connector issues. Replace the PCM only after confirming the coil, harness, connectors, and related fuses/relays are all functional.
Yes. If the fuse that supplies power to the ignition coil driver circuit is open, the PCM will see no current when commanding the coil and will set an open‑circuit code.
Driving is possible but not recommended. The affected cylinder will misfire, leading to rough running, reduced power, and potential catalytic‑converter damage over time.
Measure the primary resistance of the coil; if it reads open (infinite) or far outside the specified range, the coil is defective. Swapping it with another cylinder’s coil and seeing the code follow the coil also confirms the fault.