P2301Generic code

P2301 Code: Ignition Coil A Primary Control Circuit High

The P2301 code means the computer sees high voltage in the control circuit of ignition coil A, either an open circuit or a short to voltage. It can cause misfires on one or two cylinders, jerking and loss of power. You can drive short distances with caution, but a cylinder with no spark can damage the catalytic converter.

Severity
High
Can I keep driving?
Yes, but with caution
Estimated cost
$30 to $200
Difficulty
Medium
System
Ignition and Misfires
Applies to
All OBD2 vehicles

Updated Reviewed by Renzo Chacca

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What the P2301 code means

On engines with one coil per cylinder (coil on plug) or with dual coils, the computer controls the primary circuit of each coil: it charges the coil for a few milliseconds and then cuts the current so the spark jumps. The letters A, B, C and so on identify each coil or each control circuit depending on the manufacturer. On many engines A corresponds to cylinder 1.

The computer monitors the control circuit from its own driver transistor. The P2301 code means high voltage in the control circuit (an open circuit or a short to voltage). Before you replace the component, check the fuse, relay, connector and wiring, because they are the most common cause.

Many modern coils have the ignition transistor built in and receive a low voltage trigger signal from the computer. A short to ground or an open circuit in that signal leaves the coil with no spark.

To confirm it, measure the continuity of each wire between the component connector and the computer connector with the key off. It should be less than 1 ohm, and an infinite reading means the wire is open. If the wiring is good, measure the component itself: infinite resistance confirms it is open inside.

P2301 code symptoms

  • Check engine light or another warning light on.
  • Misfires on one or two cylinders, jerking and loss of power.

Likely causes of the P2301 code

  1. Loose or broken connector. The most common cause, especially after another repair.
  2. Coil or motor open with infinite resistance.
  3. Control wire cut between the component and the computer.
  4. Short to 12 V. The control wire touches another wire that carries voltage.

How to diagnose the P2301 code step by step

  1. Activate the component with the scan tool and check whether it responds.
  2. Check the fuse and relay. Measure the voltage on both sides of the fuse, and swap the relay with an identical one.
  3. Measure the supply at the connector. Battery voltage with the key on or when it is activated.
  4. Measure the resistance of the component and compare it with the manual. Check the insulation to ground too.
  5. Check the control wire. Continuity to the computer and no shorts.

How to fix the P2301 code

  • Repair the connector, the wiring or the supply.
  • Replace ignition coil A if it does not respond with correct power and command.
  • Clear the codes and verify.

After the repair, check the spark plug of the same cylinder and make sure the P2301 code stays away and there are no misfires on the scan tool.

Technical reference data

  • Coil with a built-in igniter: 12 V supply, ground and a trigger signal of 0 to 5 V.
  • Primary resistance of coils without a built-in igniter: 0.4 to 2 ohms.
  • Always check the spark plug of the same cylinder too.
  • These are reference values only: check the manufacturer data for your vehicle.

Brand-specific notes

This code is very common on several makes. Swapping the coil with the one from another cylinder is the quickest test: if the misfire follows the coil, the coil is bad.

P2301 on Volkswagen

Very frequent on Volkswagen 1.8T and 2.0 TFSI engines.

P2301 on Audi

Very frequent on Audi 1.8T and 2.0 TFSI engines.

P2301 on SEAT

Very frequent on SEAT 1.8T and 2.0 TFSI engines.

P2301 on Ford

Very frequent on Ford vehicles.

P2301 on Chevrolet

Very frequent on Chevrolet vehicles.

P2301 on Hyundai

Very frequent on Hyundai vehicles.

P2301 on Kia

Very frequent on Kia vehicles.

Frequently asked questions about P2301

Can I drive with a P2301 code?
Only short distances and without pushing the engine. A cylinder with no spark sends fuel to the catalytic converter and can damage it. If the light is flashing, stop driving.
What does ignition coil A do?
On engines with one coil per cylinder (coil on plug) or with dual coils, the computer controls the primary circuit of each coil. It charges the coil for a few milliseconds and then cuts the current so the spark jumps. On many engines A is cylinder 1.
Does the part always have to be replaced?
No. Check the fuses, relays, connectors and wiring first.
How much does it cost to fix P2301?
Roughly $30 to $200. A connector or wiring repair is at the low end, and a coil with labor is closer to the top.
What does the P2301 code mean?
It is a generic OBD2 code that means the primary control circuit of ignition coil A has high voltage. The cause is an open circuit or a short to voltage.
Will a P2301 code clear itself?
If a connector was only loose for a moment, the light may go out after several drive cycles. An open coil or a cut wire will bring the code back, so find the cause.
What is the most common cause of P2301?
A loose or broken connector, especially after another repair. An open coil and a cut control wire come next.

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Questions about the P2301 code

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