What Does P021F Mean?
This code indicates cylinder 12 injection timing is outside the ECM's acceptable range. On V12 engines, the ECM monitors each cylinder's injection timing individually. Cylinder 12's injector is delivering fuel at an incorrect point in the combustion cycle, affecting efficiency and emissions.
Common Causes
35%
Worn cylinder 12 injector with degraded response time causing timing offset
25%
Carbon deposits restricting the cylinder 12 injector nozzle
20%
Fuel rail pressure fluctuation affecting cylinder 12 injection event
20%
Timing chain wear or position sensor fault creating a base timing error
Diagnostic Steps
1
Step 1: Compare injection timing corrections across all 12 cylinders on a scan tool.
2
Step 2: Perform an injector balance test for cylinder 12.
3
Step 3: Swap the cylinder 12 injector with an adjacent cylinder to isolate the fault.
4
Step 4: Borescope the cylinder 12 injector tip for carbon deposits.
5
Step 5: Check timing chain and position sensor conditions to rule out base timing errors.
Estimated Repair Cost
$250 - $1,000
Parts + labor, varies by vehicle and location
This code indicates cylinder 12 injection timing is outside the ECM's acceptable range. On V12 engines, the ECM monitors each cylinder's injection timing individually. Cylinder 12's injector is delivering fuel at an incorrect point in the combustion cycle, affecting efficiency and emissions.
The most common cause of P021F (Cylinder 12 Injection Timing) is: Worn cylinder 12 injector with degraded response time causing timing offset
Typical repair costs for P021F range from $250 to $1,000, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Incorrect injection timing on cylinder 12 causes increased emissions and noise. Severe timing errors risk mechanical engine damage from abnormal combustion pressures.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P021F to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel Injection System / Engine Timing
Difficulty
Type
Generic (SAE)
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