AutoCodes – Generic – P021F

P021F Code - Cylinder 12 Injection Timing

Quick Answer

The Powertrain Control Module (PCM) can detect when unintended fuel injection occurs by monitoring fuel rail pressure and engine speed. Common causes include Faulty Fuel Injector 12, Fuel Injector 12 harness is open or shorted, Fuel Injector 12 circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P021F indicates Cylinder 12 Injection Timing.
Common causes: Common causes include Faulty Fuel Injector 12, Fuel Injector 12 harness is open or shorted, Fuel Injector 12 circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 2,270

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Apr 13, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P021F Description

The Powertrain Control Module (PCM) can detect when unintended fuel injection occurs by monitoring fuel rail pressure and engine speed. If this condition occurs, the engine will typically die and not start. There will be exhaust smoke during cranking and no fuel rail pressure will be developed during cranking. This Detected Trouble Code (DTC) will be active during cranking if this condition exists. Progressive cylinder damage may occur if the engine is operated for an extended period of time with this condition. This fault code is logged when the PCM determines that unintended fuel injection has occurred. The PCM sets the OBDII code when determines that unintended fuel injection has occurred.

OBDII Code P021F - Cylinder 12 Injection Timing - AutoCodes.com — P021F Code - Cylinder 12 Injection Timing

What does this mean?

What are the Possible Causes of the DTC P021F?

Faulty Fuel Injector 12
Fuel Injector 12 harness is open or shorted
Fuel Injector 12 circuit poor electrical connection
Faulty Crankshaft or Camshaft Position Sensor

How to Fix the DTC P021F?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P021F code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Information for Specific Makes

P021F Dodge — Fuel Injector 12 Performance

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.