Geely Fault Code

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P0171

Hesitation / Lean System MIL

System

Fuel / Air Induction

Symptom

Hesitation / Lean System MIL

Diagnosis & fix steps

LOGIC: Fuel Trim System Too Lean (Bank 1 Positive LTFT >20%). ACTION: Smoke test intake manifold and turbo inlet boot. Check crankcase ventilation (PCV) diaphragm built into the plastic valve cover for an internal tear allowing unmetered false air.

Red Seal field insights

Valve Cover PCV Failure: The integrated rubber PCV diaphragm inside the composite cam cover ruptures, drawing crankcase vacuum straight into the intake runner without MAF metering.

Same code keeps coming back?

That's a program problem, not a part problem. Book a 30-minute uptime review with Grant, a Red Seal Heavy Duty Technician.

Book an uptime review

Read before you touch anything

  • This is general reference information, not a repair manual. It is for trained, qualified technicians.
  • Fault codes, meanings and procedures vary by model, serial number and software version. Confirm the code and the procedure against the manufacturer's service manual before acting.
  • Follow the OEM service manual, torque specs and your site's safety procedures: lockout/tagout, block raised equipment, relieve hydraulic, fuel and air pressure, and let hot systems cool.
  • You use this information at your own risk. Adventure Mechanical and AM Fleet Integrity accept no liability for damage, injury, downtime or loss arising from its use.
  • Not affiliated with or endorsed by any manufacturer. Brand names are used only to identify the equipment a code applies to.

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