🚨 Code P0201: Faulty Injector (Cylinder 1 Circuit)
🔧 Definition
This generic code (DTC) relates to the powertrain and applies to all OBD-II vehicles. Repair steps may vary by make/model.
💻 PCM Problem
The Powertrain Control Module (PCM) has detected a fault in the #1 injector circuit. It monitors:
- ⚡ Low voltage (close to 0V) when the injector is activated.
- 🔋 High voltage (close to battery voltage) when the injector is deactivated.
If the circuit voltage or resistance is abnormal, code P0201 is set.
⚠️ Symptoms
- Engine 🎇 stalling or running rough.
- 🚗 Poor acceleration.
- 🔅 MIL (Malfunction Indicator Lamp) illuminated.
🔍 Possible Causes
| 🛠️ Faulty injector | Most common cause. |
| 🔌 Damaged wiring | Short circuit or open circuit. |
| 🤖 Faulty PCM | Rare, but should be checked. |
🛠️ Solutions
- 📏 Check injector resistance
- Use a multimeter (DVOM). If out of specification, replace the injector.
- 🔋 Test voltage at the connector
- Should read 10V or more.
- 🔎 Visual inspection
- 🧰 Injector: Cracks or leaks.
- 🔌 Connectors/wiring: Corrosion, breaks, or burns.
- ⚡ Test the injector
- With a tester: Activate it to check operation.
- Without a tester: Temporarily swap with a known good injector.
- 🔌 Check PCM circuit
- Disconnect the PCM connector and test the relevant wire (for ground).
- 🔄 Replace the injector
- If the code persists after testing, install a new injector.
🚗 Tip
If the PCM is suspected, consult a professional before any intervention!