P2330

Ignition CoilKPrimary Control Circuit Low

P2330 is a generic OBD-II powertrain diagnostic trouble code: Ignition CoilKPrimary Control Circuit Low. It is logged by the engine control unit when the powertrain monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P2330
Group
Powertrain
System
Powertrain
Severity
Warning (MIL on)
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What P2330 means

P2330 is set when the ECM detects that the primary control circuit voltage for ignition coil B is higher than expected, or that the circuit does not pull low as commanded. In a typical coil-on-plug system the ECM drives the coil primary circuit to ground to initiate a spark; a high condition indicates the ground path is open or the driver is unable to complete the circuit, leaving the primary circuit voltage near battery level when it should be at or near zero.

This is purely a primary-side electrical fault and does not directly describe a coil winding failure, though an open primary winding inside the coil will produce the same circuit behavior. The most common causes are a broken or high-resistance wire in the coil primary ground circuit, a poor connection at the coil connector, or an open coil primary winding. An internal ECM driver fault is less common but possible.

The affected cylinder will not fire, producing a definite cylinder-specific misfire. The ECM will typically disable the fuel injector for that cylinder as well to protect the catalytic converter from raw fuel. Diagnosis is straightforward: verify supply voltage, check the ground-side driver wire continuity, and swap the coil to confirm whether the fault is in the coil or the harness.

Common causes

Most-frequently reported root causes when P2330 is logged.

  • 1
    Open circuit or broken wire in the ignition coil B primary ground control circuit.
  • 2
    Corroded or loose connector at the coil B connector preventing ground path completion.
  • 3
    Open primary winding inside ignition coil B.
  • 4
    Short-to-voltage on the primary control wire holding the circuit high.
  • 5
    Damaged ECM ignition driver output for coil B circuit.
  • 6
    Blown fuse or relay in the ignition coil power supply circuit.
  • 7
    Water or corrosion intrusion at the coil harness connector.

Symptoms drivers notice

MIL illuminated with a hard misfire on the cylinder served by coil B.
Rough idle and engine vibration due to a dead cylinder.
Reduced power and acceleration performance.
Possible raw fuel smell from the exhaust if injector cutoff is not active.
Catalytic converter overheating if the fault is intermittent and injector cut is not applied.

How to diagnose P2330

A typical diagnostic flow when this code is present.

  1. 1
    Retrieve all DTCs and freeze-frame data; note any companion misfire codes.
  2. 2
    Check ignition coil B supply voltage at the connector with the ignition on.
  3. 3
    With the ignition on, probe the primary control wire and verify it pulls low when the ECM commands a spark.
  4. 4
    Measure resistance of the primary coil winding and compare to specification.
  5. 5
    Inspect the harness connector at coil B for corrosion, bent pins, or broken wires.
  6. 6
    Swap the coil to another cylinder and clear codes; if the fault moves, replace the coil.
  7. 7
    If the fault stays on cylinder B with a known-good coil, trace the control wire back to the ECM for opens or shorts.

Related powertrain codes

Frequently asked questions

What is the difference between P2330 high and a primary open code?

P2330 specifically indicates the circuit voltage is high (the driver cannot pull it low), which points to an open in the ground-side path rather than a short-to-ground.

Can I drive with P2330?

The vehicle will run on fewer cylinders and extended driving risks catalytic converter damage from misfiring; repair is recommended promptly.

Does P2330 always mean the coil is bad?

No. A broken wire or corroded connector in the primary circuit can cause the same code; always check wiring continuity before replacing the coil.

Will the ECM be damaged if this code is ignored?

The ECM driver can be stressed by repeated failed switching events; while damage is not immediate, prolonged operation with this fault is not recommended.

Disabling P2330 in software

RaceTune can permanently disable P2330 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.

Permanent
The monitor is disabled in the ECU itself — not just cleared. It cannot return.
Tailored to your file
Each patch is matched to your specific software version — never a one-size-fits-all file.
Reversible
The original file is always preserved. Reflash the stock to return the ECU to factory state.

Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.

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