P0201Generic code

P0201 Code: Injector Circuit Malfunction, Cylinder 1

The P0201 code means the computer detected an electrical fault in the cylinder 1 injector circuit. The cylinder 1 injector may not open, and that cylinder will misfire (it often appears together with P0301).

Severity
Medium
Can I keep driving?
Yes, but with caution
Estimated cost
$20 to $500
Difficulty
Medium
System
Fuel Injection
Applies to
All OBD2 vehicles

Updated Reviewed by Renzo Chacca

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What the P0201 code means

Each injector gets 12 V all the time, and the computer opens it by connecting its other terminal to ground for a few milliseconds. While it does that, it watches the circuit voltage. When the injector closes, the coil produces a characteristic voltage spike. If the computer does not see the expected voltage or spike, it stores the P0201 code.

Because it is located at cylinder 1, the fault is usually in that injector, in its connector or in its wire to the computer. Cylinder numbering depends on the manufacturer. On most inline engines, cylinder 1 is the one closest to the timing belt or chain. On V engines, the odd and even cylinders usually sit on different banks. Confirm the numbering in the service manual before you take anything apart.

An injector that does not open leaves that cylinder with no fuel. The engine shakes, and the computer may also log a misfire for that cylinder.

P0201 code symptoms

  • Check engine light on.
  • Engine shaking, especially at idle.
  • Loss of power.
  • Misfire in the affected cylinder.
  • Gas smell or high fuel consumption if the injector stays open.

Likely causes of the P0201 code

  1. Injector 1 connector loose, broken or corroded. The most common cause, because the plastic clips break with heat.
  2. Injector 1 coil open or shorted. Measure its resistance.
  3. Control wire cut or chafed between the injector and the computer.
  4. 12 V supply missing at the connector of that injector.
  5. Computer driver for that injector. Uncommon, and it usually gets damaged when the injector was shorted.

How to diagnose the P0201 code step by step

  1. Read the codes and the misfire counters to confirm which cylinder is failing.
  2. Inspect the connector of injector 1.
  3. Measure the injector resistance and compare it with the others. They should all read a similar value (approximately 11 to 18 ohms on a high impedance injector).
  4. Check for 12 V at the connector with the key on.
  5. Connect an injector test light (noid light) to the connector and crank the engine. It should flash. If it does not flash, the problem is in the control wire or in the computer.
  6. Swap the injector with the one from a neighboring cylinder. If the fault moves to the other cylinder, the injector is the culprit.

How to fix the P0201 code

  • Repair or replace the injector connector.
  • Replace the injector if its resistance is out of range.
  • Repair the control wire or the supply.
  • If the computer injector driver is damaged, first replace the shorted injector that burned it out.
  • Clear the codes and check in live data that there are no misfires.

Technical reference data

  • High impedance gasoline injector: 11 to 18 ohms.
  • Low impedance injector: 2 to 5 ohms.
  • Typical supply: 12 V from a relay or the computer. The computer switches the ground to open the injector.
  • Piezoelectric common rail diesel injectors are not tested with an ohmmeter the same way. They follow the manufacturer procedure.
  • Approximate values: check the manufacturer data for your engine.

Brand-specific notes

Injector connectors age with heat and vibration, so inspect them before you order parts. That matters if you are chasing the P0201 code and the injector resistance tests out fine.

P0201 on Ford

It is common for the connector clip to break and the injector to lose contact with vibration. On direct injection engines (Ford EcoBoost) the injectors run at a higher voltage, so do not use a conventional test light without checking the procedure.

P0201 on Nissan

It is common for the connector clip to break and the injector to lose contact with vibration.

P0201 on Chrysler

It is common for the connector clip to break and the injector to lose contact with vibration.

P0201 on Volkswagen

On direct injection engines (TSI) the injectors run at a higher voltage, so do not use a conventional test light without checking the procedure.

P0201 on Hyundai

On direct injection engines (GDI) the injectors run at a higher voltage, so do not use a conventional test light without checking the procedure.

Frequently asked questions about P0201

What does the P0201 code mean?
It means the computer found an electrical fault in the cylinder 1 injector circuit. The injector may not open, and that cylinder will misfire.
Can I drive with a P0201 code?
With caution and only for a short time. A cylinder with no fuel makes the engine shake and, if there are misfires, the catalytic converter can be damaged.
Does P0201 always mean replacing the injector?
No. Many times it is the connector or the wire. Check the resistance and the signal before you buy anything.
How do I know which cylinder is affected?
Cylinder numbering depends on the manufacturer. On most inline engines, cylinder 1 is the one closest to the timing belt or chain. On V engines, the odd and even cylinders usually sit on different banks. Confirm the numbering in the service manual before you take anything apart.
How much does it cost to fix P0201?
Roughly $20 to $500, from a connector up to a new injector with labor (more on a diesel). The final number depends on the shop and the engine.
Will a P0201 code clear itself?
Only if the cause goes away. A loose connector or a chafed wire will bring the code back, so clearing it without a repair only hides it for a while.
What is the most common cause of P0201?
A loose, broken or corroded injector connector, because the plastic clips break with heat. Inspect it and check the injector resistance before you buy a new injector.

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