Open circuit or high resistance in the wiring between the control unit and coil I primary control wire; Corroded, loose or damaged connector at coil I; Failed ignition coil I (internal open primary winding or faulty built-in driver); Missing or faulty power or earth supply to the coil; Chafed or heat-damaged harness near the engine causing intermittent open circuit; Fault in the engine control unit driver circuit.

P0359

Ignition Coil I Primary Control Circuit/Open.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
3: AreaIgnition system or misfire
59: FaultThe specific fault in that area

What it means

P0359 means the engine control unit has detected a fault in the primary control circuit of ignition coil 'I', the ninth coil in the manufacturer's labelling, with an open circuit as the typical fault. The control unit monitors the coil driver or the ignition feedback signal, and sets the code when the expected switching or current response is missing. Which cylinder 'I' refers to depends on the engine and manufacturer, so confirm this in the model's service data.

Symptoms

Engine misfire on one cylinder, especially under load
Rough or unstable idle
Hesitation or loss of power
Malleable or flashing engine warning light
Hard starting or occasional stalling
Raised fuel consumption

Possible causes

Open circuit or high resistance in the wiring between the control unit and coil I primary control wirelikely
Corroded, loose or damaged connector at coil Ilikely
Failed ignition coil I (internal open primary winding or faulty built-in driver)likely
Missing or faulty power or earth supply to the coilpossible
Chafed or heat-damaged harness near the engine causing intermittent open circuitpossible
Fault in the engine control unit driver circuitrare

How to diagnose

Read all stored codes and freeze frame data to see load, rpm and temperature when the fault set, and check for related misfire codes.
Confirm from the service information which cylinder and coil position 'I' relates to on this engine.
Visually inspect the coil connector, harness and surrounding wiring for damage, corrosion, oil contamination or heat damage.
Check the coil connector pins for tightness and signs of fretting, and wiggle test the harness with the engine running while watching live misfire data.
Swap coil I with a known good coil on a neighbouring cylinder, clear the code and see whether the fault follows the coil.
Check the coil's power supply and earth with a multimeter against the wiring diagram.
Test the control wire for continuity and shorts to earth or supply between the coil connector and control unit, with the connector disconnected.
If wiring and coil are proven good, check the control unit connector and driver output with an oscilloscope before considering the control unit.

How to fix

Repair or replace damaged wiring in the coil control circuit, using proper soldered or crimped repairs.
Clean, repair or replace a corroded or damaged coil connector or terminals.
Replace the faulty ignition coil, and check the spark plug in that cylinder at the same time.
Restore the coil's power supply or earth connection if a fault is found.
Replace or repair the engine control unit only after all wiring and the coil have been proven good.

Can I keep driving?

Medium severity

Short, gentle journeys are possible, but avoid heavy loads and high revs. A persistent misfire can send unburnt fuel into the catalytic converter and damage it, so have it fixed soon, and stop driving if the warning light flashes.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.