HomeTrouble CodesP0359

P0359 — Ignition Coil I Primary Control Circuitopen

Generic OBD-II · all makesPowertrain (engine & transmission)

P0359 indicates that the powertrain control module has detected an open circuit in the primary side of ignition coil I. This means the PCM is not seeing the expected voltage signal when it tries to energize the coil, which can prevent the coil from firing properly.

Symptoms

What causes it — most likely first

1. Failed ignition coil primary winding

The coil’s internal primary circuit has opened, preventing the PCM from driving the coil. This is the most common cause of P0359.

2. Open or high‑resistance wiring in the coil‑to‑PCM harness

A broken wire, chafed insulation, or corroded pin in the harness between the PCM and coil I creates an open circuit.

3. Damaged or loose connector at the coil or PCM

Corrosion, bent pins, or a partially disengaged connector can interrupt the primary‑circuit signal.

4. Blown fuse or faulty relay supplying power to the coil driver circuit

If the fuse or relay that powers the coil driver stage is open, the PCM will see no voltage on the primary circuit.

5. PCM driver circuit failure (less common)

The transistor or driver inside the PCM that switches the coil primary can fail, but this is rare compared to coil or wiring issues.

How it's diagnosed

  1. Verify the code and check for any related codes (e.g., other coil or misfire DTCs).
  2. Inspect the ignition coil I connector and wiring for damage, corrosion, or loose pins; repair as needed.
  3. Measure the primary‑circuit resistance of the coil (typically < 1 Ω) with a multimeter; replace the coil if out of spec.
  4. Check continuity of the harness from the PCM pin to the coil connector; repair any open or high‑resistance wires.
  5. Test the fuse and relay that supply the coil driver circuit; replace if blown or faulty.
  6. If all wiring, connectors, coil, fuse, and relay are good, monitor the PCM’s driver output with an oscilloscope or scan tool to confirm PCM functionality.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationSAE generic — identical on every make

Frequently asked

Do I need to replace the PCM for a P0359 code?

No. The PCM is rarely the cause; most P0359 cases are due to a faulty coil, wiring, or connector. Only consider PCM replacement after those components have been verified good.

Can a blown fuse cause P0359?

Yes. If the fuse that powers the coil driver circuit is open, the PCM will see no voltage on the primary coil circuit and set P0359.

Is it safe to drive with a P0359 code?

Driving is possible but not recommended; the misfire can cause rough running, loss of power, and potential damage to the catalytic converter over time.

Will clearing the code fix the problem?

Clearing the code only turns off the Check Engine Light; the underlying open circuit must be repaired, or the code will return.