P039C
Cylinder 1 Pressure Variation Low
P039C is an OBD-II diagnostic trouble code meaning: Cylinder 1 Pressure Variation Low. Common causes: low compression in cylinder 1, faulty or clogged fuel injector of cylinder 1. Estimated repair cost: $33–222.
Symptoms
- Check Engine light on
- Misfire in cylinder 1
- Unstable idle
- Loss of engine power
- Increased exhaust toxicity
Causes
- Low compression in cylinder 1
- Faulty or clogged fuel injector of cylinder 1
- Weak spark plug or faulty coil
- Cylinder pressure sensor malfunction
- Leaking valves or head gasket
How to Fix
- Perform a compression test on cylinder 1 to assess the condition of the piston rings and valves
- Check the spark plug and ignition coil of cylinder 1
- Diagnose the fuel injector of cylinder 1 (balance, spray)
- Check the pressure sensor and its circuit for serviceability
- If necessary, perform a cylinder leak test.
- Eliminate faults found and reset error codes
Related codes
Error P039C by Vehicle Brand
FAQ
What does the P039C code mean?
P039C is an OBD-II diagnostic trouble code that indicates: Cylinder 1 Pressure Variation Low
What causes a P039C error code?
The most common causes of P039C include: Low compression in cylinder 1; Faulty or clogged fuel injector of cylinder 1; Weak spark plug or faulty coil; Cylinder pressure sensor malfunction.
How do I fix a P039C diagnostic trouble code?
To fix P039C: Perform a compression test on cylinder 1 to assess the condition of the piston rings and valves. Check the spark plug and ignition coil of cylinder 1. Diagnose the fuel injector of cylinder 1 (balance, spray). For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P039C?
Do not drive — repair immediately
How much does it cost to fix P039C?
The estimated repair cost for P039C is $33–222. Actual cost depends on your vehicle, location, and labor rates.
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