Infiniti Code P1165: Definition, Causes, Symptoms, and Solutions
Meaning of Code P1165
Code P1165 on Infiniti vehicles indicates a problem with the Swirl Control Valve Vacuum Control Switch Circuit. This system optimizes airflow in the intake manifold to improve engine efficiency.
- Operation:
- The vacuum control switch detects the presence of vacuum sent to the swirl valve.
- It sends an ON (vacuum detected) or OFF (no vacuum) signal to the ECM (Engine Control Module).
- This system is primarily used for on-board diagnostics, not for active engine control.
- Consequences: An incorrect signal can disrupt ECM diagnostics, although engine performance often remains normal.
Common Symptoms
- 🟠 Check Engine Light illuminated (MIL) or warning message.
- 🌀 Degraded swirl system operation (rarely noticeable during normal driving).
Possible Causes
- Mechanical Problems:
- Clogged or cracked vacuum hose to the switch.
- Vacuum control switch failure.
- Electrical Problems:
- Open or short circuit in the solenoid valve wiring harness.
- Faulty connection (corroded terminals, loose connector).
- Faulty swirl control solenoid valve.
- Electronic Failure:
- Faulty ECM (rare).
Diagnostic Procedures
Preliminary Steps
- Visual Inspection:
- Check the vacuum hoses for obstructions, cracks, or disconnections.
- Inspect the electrical connectors and wiring of the solenoid valve and switch (look for bent, corroded, or broken pins).
- Solenoid Valve Test:
- Disconnect the solenoid valve and measure its resistance with a multimeter (typically between 10 and 30 Ω).
- If the resistance is out of specification → Replace the solenoid valve.
- Vacuum Control Switch Test:
- Use a manual vacuum pump to apply vacuum to the switch.
- Check with a multimeter if the switch sends a consistent ON/OFF signal to the ECM.
- Electrical Circuit Test:
- Check for continuity and the absence of short circuits in the wires connecting the solenoid valve and switch to the ECM.
- Ensure the circuit power supply (+12V) and ground are intact.
Repair Solutions
- 🔧 Replace the vacuum hose: If it is clogged or damaged.
- 🔌 Repair the wiring: Replace damaged wires, clean oxidized connectors.
- 🛠️ Replace the solenoid valve or switch: In case of confirmed failure.
- 💻 Reset the ECM: Clear the code with an OBD2 scanner after repair.
Practical Tips
- ⚠️ Safety: Disconnect the battery before handling electrical circuits.
- 📚 Documentation: Consult the Infiniti service manual for technical specifications (resistance, wiring diagrams).
- 🔄 Final Verification: After repair, test the system by driving to confirm the code does not reappear.
In Summary
Code P1165 on Infiniti indicates a malfunction in the vacuum control circuit related to the swirl valve. Although symptoms are often subtle, prompt repair is recommended to avoid future diagnostic issues.
- Priorities: Inspect vacuum hoses, test the solenoid valve and switch.
- Typical Solution: Replacement of faulty components (hose, solenoid valve, switch).
- Expertise: If the code persists, consult a qualified technician to analyze the ECM or complex faults.
Ignoring this code can lead to future diagnostic errors or swirl system performance issues.