AutoCodes – GMC – P020A GMC

P020A GMC Code - Cylinder 1 Injection Timing

Quick Answer

The Engine Control Module (ECM) has the ability to learn injector timing performance. Common causes include Faulty Fuel Injector 1, Fuel Injector 1 harness is open or shorted, Fuel Injector 1 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: P020A GMC indicates Cylinder 1 Injection Timing.
Common causes: Common causes include Faulty Fuel Injector 1, Fuel Injector 1 harness is open or shorted, Fuel Injector 1 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 388

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 Mar 22, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P020A GMC Description

The Engine Control Module (ECM) has the ability to learn injector timing performance. When the engine is at operating temperature, throttle closed and in deceleration fuel cut-off mode, the ECM will pulse each injector individually and measure the changes in rotational speed of the crankshaft using the input from the crankshaft position sensor. The ECM will run this diagnostic at one fuel rail pressure operating point for each injector. The ECM stores the injector timing value. The Diagnostic Trouble Code (DTC) will be set when the time to build up sufficient current to open the injector is below or above a predetermined threshold.

OBDII Code P020A GMC - Cylinder 1 Injection Timing - AutoCodes.com — P020A GMC Code - Cylinder 1 Injection Timing

What does this mean?

What are the Possible Causes of the DTC P020A GMC?

Faulty Fuel Injector 1
Fuel Injector 1 harness is open or shorted
Fuel Injector 1 circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P020A GMC?

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 P020A GMC 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.

Need more information about the P020A GMC code?

Need more information on how to fix the P020A GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

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Information for Specific GMC Models

P020A 2014 GMC Sierra — Cylinder 1 Injection Timing
P020A 2015 GMC Sierra — Cylinder 1 Injection Timing
P020A 2016 GMC Sierra — Cylinder 1 Injection Timing
P020A 2017 GMC Sierra — Cylinder 1 Injection Timing
P020A 2018 GMC Sierra — Cylinder 1 Injection Timing

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.

Frequently Asked Questions about P020A GMC Code

What does the OBD-II code P020A mean for a GMC vehicle?

P020A indicates an issue with the injection timing for Cylinder 1, usually related to the fuel injector circuit or timing control.

What are the common symptoms of code P020A in a GMC?

Symptoms may include rough idling, misfires, reduced power, poor fuel economy, or difficulty starting the engine.

What causes the P020A code to appear?

Potential causes include a faulty fuel injector, wiring issues, a bad injector driver in the PCM, or inadequate fuel pressure.

Can driving with the P020A code damage my GMC's engine?

Yes, prolonged driving with this code can lead to misfires, increased emissions, and potential engine damage.

How can I diagnose the P020A code in a GMC?

Start by inspecting the wiring and connectors for Cylinder 1's fuel injector, then test the injector itself and check for PCM-related issues.

How do I fix the P020A code on my GMC?

Repairs may include replacing the faulty fuel injector, repairing damaged wiring, or reprogramming/replacing the PCM if needed.

Is the P020A code specific to GMC vehicles?

No, P020A is a generic OBD-II code that can appear in various makes and models, but the diagnostic steps may vary slightly.

Are there any tools required to diagnose the P020A code?

Yes, tools like an OBD-II scanner, multimeter, and fuel pressure gauge can help pinpoint the issue.

How much does it cost to repair a P020A code on a GMC?

The cost depends on the root cause but can range from $150 for wiring repairs to over $500 for injector or PCM replacement.

Can a dirty fuel injector cause the P020A code?

Yes, a clogged or dirty injector can disrupt proper injection timing and trigger this code. Cleaning or replacing the injector may solve the issue.

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