AutoCodes – GMC – P021A 2018 GMC Sierra

P021A 2018 GMC Sierra Code - Cylinder 7 Injection Timing

Quick Answer

The Engine Control Module (ECM) has the ability to learn injector timing performance. Common causes include Faulty Fuel Injector 7, Fuel Injector 7 harness is open or shorted, Fuel Injector 7 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: P021A 2018 GMC Sierra indicates Cylinder 7 Injection Timing.
Common causes: Common causes include Faulty Fuel Injector 7, Fuel Injector 7 harness is open or shorted, Fuel Injector 7 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 198

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 P021A 2018 GMC Sierra 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 P021A 2018 GMC Sierra - Cylinder 7 Injection Timing - AutoCodes.com — P021A 2018 GMC Sierra Code - Cylinder 7 Injection Timing

What does this mean?

What are the Possible Causes of the DTC P021A 2018 GMC Sierra?

Faulty Fuel Injector 7
Fuel Injector 7 harness is open or shorted
Fuel Injector 7 circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P021A 2018 GMC Sierra?

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 P021A 2018 GMC Sierra 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 P021A 2018 GMC Sierra code?

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Need Help with the Code?

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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 P021A 2018 GMC Sierra Code

1. What are the common symptoms of OBDII code P021A in a 2018 GMC Sierra related to Cylinder 7 Injection Timing?

The common symptoms include engine misfires, rough idling, reduced power, and potentially increased fuel consumption.

2. What are the possible causes of OBDII code P021A in a 2018 GMC Sierra?

Possible causes of this code could include issues with the fuel injector, wiring or connector problems, a faulty engine control module (ECM), or a problem with the fuel injection timing sensor.

3. How can I diagnose the issue causing OBDII code P021A in my 2018 GMC Sierra?

Diagnosis typically involves using a scan tool to retrieve the code, checking the related components such as the fuel injector and wiring, performing a visual inspection for any obvious issues, and potentially conducting further tests to pinpoint the exact cause.

4. Can I still drive my 2018 GMC Sierra with OBDII code P021A related to Cylinder 7 Injection Timing?

It is not recommended to drive the vehicle with this code present, as it can lead to further damage to the engine and potentially worsen the issue.

5. How can I repair OBDII code P021A in my 2018 GMC Sierra?

Repair options may include replacing the faulty fuel injector, repairing any wiring or connector issues, replacing the ECM if necessary, or addressing any problems with the fuel injection timing sensor.

6. Will resetting the OBDII code P021A in my 2018 GMC Sierra fix the issue?

Simply resetting the code may temporarily clear the warning light, but it will not fix the underlying problem causing the code to trigger. It is important to diagnose and repair the issue to prevent it from reoccurring.

7. Are there any maintenance tips to prevent OBDII code P021A in a 2018 GMC Sierra?

Regular maintenance, such as using high-quality fuel, keeping up with oil changes, and ensuring proper fuel system function, can help prevent issues that may trigger this code.

8. How much does it typically cost to repair OBDII code P021A in a 2018 GMC Sierra?

The cost of repair can vary depending on the exact cause of the issue, the parts needed for replacement, and labor costs. It is advisable to consult a professional mechanic for an accurate estimate.

9. Can a DIY enthusiast fix OBDII code P021A in a 2018 GMC Sierra?

While some experienced DIY enthusiasts may be able to diagnose and repair this issue, it is recommended to seek assistance from a qualified mechanic due to the complexity of the potential causes and repairs involved.

10. Is OBDII code P021A in a 2018 GMC Sierra a common issue?

While not extremely common, this code related to Cylinder 7 Injection Timing can occur in vehicles, including the 2018 GMC Sierra, due to various factors affecting the fuel injection system.