AutoCodes – GMC – P1089 GMC

P1089 GMC Code - Fuel Rail Pressure Performance During Deceleration Fuel Cut-Off

Quick Answer

The Engine Control Module (ECM) monitors for changes in fuel rail pressure when the vehicle is in a deceleration condition and the fuel injected quantity is at zero. Common causes include Faulty Fuel Injector, Faulty Fuel Pressure Regulator, Fuel Pressure Regulator harness is open or shorted. 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: P1089 GMC indicates Fuel Rail Pressure Performance During Deceleration Fuel Cut-Off.
Common causes: Common causes include Faulty Fuel Injector, Faulty Fuel Pressure Regulator, Fuel Pressure Regulator harness is open or shorted.
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 13,832

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 Jul 24, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1089 GMC Description

The Engine Control Module (ECM) monitors for changes in fuel rail pressure when the vehicle is in a deceleration condition and the fuel injected quantity is at zero. When scan tool parameter Deceleration Fuel Cut-Off is active, the fuel rail pressure should not deviate more than 2 MPa (290 PSI) from a calculated setpoint. If the fuel rail pressure deviates more than 2. MPa (290 PSI) from the calculated setpoint for approximately 10 seconds of cumulative deceleration (this may take multiple drive cycles), the Diagnostic Trouble Code (DTC) will set.

OBDII Code P1089 GMC - Fuel Rail Pressure Performance During Deceleration Fuel Cut-Off - AutoCodes.com — P1089 GMC Code - Fuel Rail Pressure Performance During Deceleration Fuel Cut-Off

What does this mean?

What are the Possible Causes of the DTC P1089 GMC?

Faulty Fuel Injector
Faulty Fuel Pressure Regulator
Fuel Pressure Regulator harness is open or shorted
Fuel Pressure Regulator circuit poor electrical connection

How to Fix the DTC P1089 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 P1089 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 P1089 GMC code?

Need more information on how to fix the P1089 GMC code? Get Access to Factory Service Manuals

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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 P1089 GMC Code

1. What are the common symptoms of OBDII code P1089 in a GMC vehicle?

- Common symptoms include rough idling, engine stalling, poor acceleration, and a decrease in fuel efficiency.

2. What are the potential causes of OBDII code P1089 in a GMC vehicle?

- Possible causes include a faulty fuel pressure sensor, a clogged fuel filter, a failing fuel pump, or issues with the fuel injectors.

3. How can I diagnose OBDII code P1089 in my GMC vehicle?

- Diagnose the code by checking the fuel pressure using a gauge, inspecting the fuel rail for leaks or blockages, and testing the fuel pressure sensor for proper functioning.

4. Can I drive my GMC vehicle with OBDII code P1089?

- It is not recommended to drive your vehicle with this code as it can lead to further engine damage and potential safety hazards.

5. How can I repair OBDII code P1089 in my GMC vehicle?

- Repair options may include replacing the fuel pressure sensor, cleaning or replacing the fuel filter, repairing or replacing the fuel pump, or addressing any fuel injector issues.

6. Is it possible for a DIY enthusiast to fix OBDII code P1089 in a GMC vehicle?

- While some repairs related to this code may be DIY-friendly, it is recommended to have a professional mechanic diagnose and repair the issue to ensure proper resolution.

7. How much does it typically cost to fix OBDII code P1089 in a GMC vehicle?

- The cost of repair can vary depending on the specific issue causing the code, but it may range from a few hundred to a few thousand dollars, including parts and labor.

8. Are there any preventive measures to avoid OBDII code P1089 in a GMC vehicle?

- Regular maintenance, such as fuel system inspections and timely fuel filter replacements, can help prevent issues that may trigger this code.

9. Can weather conditions affect OBDII code P1089 in a GMC vehicle?

- Extreme temperatures or humidity levels can sometimes exacerbate fuel system issues that lead to this code, so it's important to monitor your vehicle's performance in varying weather conditions.

10. Will resetting the OBDII code P1089 clear the issue permanently?

- Simply resetting the code may temporarily clear the warning light, but if the underlying issue is not addressed, the code is likely to reappear. It's crucial to diagnose and fix the root cause of the problem.