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P0283 — Cylinder 8 Injector Circuit High

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

Diagnostic trouble code P0283 indicates that the powertrain control module (PCM) has detected a high voltage condition on the fuel injector circuit for cylinder 8. This typically means the injector control wire is shorted to a voltage source, or the injector itself has an internal short, causing the circuit voltage to exceed expected limits.

Symptoms

What causes it — most likely first

1. Shorted fuel injector (cylinder 8)

Internal short in the injector solenoid can cause high circuit voltage. This is the most common cause.

2. Injector control wire shorted to voltage

The wiring between the PCM and injector may be chafed or pinched, contacting a power source such as battery voltage or a 5V reference wire.

3. Poor electrical connection at injector

Corrosion, bent pins, or a loose connector at the cylinder 8 injector can create erratic signals that the PCM interprets as high voltage.

4. Open or high resistance in injector ground circuit

A broken wire or high resistance in the injector's ground path can cause the driver to float high, mimicking a high-voltage condition.

5. Faulty PCM

A damaged injector driver inside the PCM is possible but rare. This should only be considered after all wiring and injector tests pass.

How it's diagnosed

  1. Use a scan tool to verify P0283 is active and check for other codes. Record freeze frame data.
  2. Visually inspect the cylinder 8 injector connector and wiring harness for damage, corrosion, or signs of shorting to power.
  3. Disconnect the injector and measure its resistance with a multimeter. Compare to manufacturer specification (typically 11-18 ohms). A very low reading indicates a shorted injector.
  4. With the injector disconnected, use a noid light or multimeter on the PCM control wire to check for a short to voltage. The light should not illuminate with key on, engine off.
  5. Perform a continuity and short-to-ground test on the injector control circuit between the PCM and injector connector.
  6. If all wiring and injector tests pass, a faulty PCM driver may be suspected. This should be confirmed with an oscilloscope or by substituting a known-good PCM.

Code facts & related codes

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

Frequently asked

Can I drive with a P0283 code?

It is not recommended. A high voltage condition on the injector circuit can cause a constant misfire, which may damage the catalytic converter and lead to unsafe driving conditions.

Is the PCM usually the cause of P0283?

No. The PCM is rarely the cause. The problem is almost always a shorted injector, wiring short to power, or a poor connection. The PCM should only be suspected after thorough testing of the injector and circuit.

What is the difference between P0283 and P0208?

P0208 is a generic injector circuit malfunction for cylinder 8, while P0283 specifically indicates a high voltage condition on that circuit. P0283 helps narrow the diagnosis to a short to voltage or a shorted injector.

Can a bad injector cause this code?

Yes. An internally shorted fuel injector is one of the most common causes of P0283. The low resistance allows excessive current flow, which the PCM detects as a high voltage condition.