AutoCodes – GMC – P1093 GMC

P1093 GMC Code - Fuel Rail Pressure Low During Power Enrichment

Quick Answer

The Engine Control Module (ECM) uses the Fuel Rail Pressure (FRP) Sensor to determine fuel pressure to the fuel injectors. Common causes include Blocked fuel filter, Faulty Fuel Rail Pressure (FRP) Sensor, Fuel Rail Pressure Sensor 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: P1093 GMC indicates Fuel Rail Pressure Low During Power Enrichment.
Common causes: Common causes include Blocked fuel filter, Faulty Fuel Rail Pressure (FRP) Sensor, Fuel Rail Pressure Sensor 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 4,368

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 03, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P1093 GMC Description

The Engine Control Module (ECM) uses the Fuel Rail Pressure (FRP) Sensor to determine fuel pressure to the fuel injectors. This is then compared to the calculated target fuel pressure as determined by the ECM. The ECM adjusts the FRP by modulating the duty cycle of the control driver of the fuel pressure regulator. Injector pulse duration is determined by the measured rail pressure and the target injection fuel into each cylinder. If a sensor circuit malfunction is detected, or the commanded fuel injection pump flow is not within the proper range for a given engine load and speed, the Diagnostic Trouble Code (DTC) will be set.

OBDII Code P1093 GMC - Fuel Rail Pressure Low During Power Enrichment - AutoCodes.com — P1093 GMC Code - Fuel Rail Pressure Low During Power Enrichment

What does this mean?

What are the Possible Causes of the DTC P1093 GMC?

Blocked fuel filter
Faulty Fuel Rail Pressure (FRP) Sensor
Fuel Rail Pressure Sensor harness is open or shorted
Fuel Rail Pressure Sensor circuit poor electrical connection

How to Fix the DTC P1093 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 does this mean?

Code Tech Notes

There is a Factor Service Bulletin for the following GMC models:
2001-2004 GMC Sierra
2003-2004 GMC Topkick C4500/C5500 Series
GMC Factory Service Bulletin OBDII Code P1093

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1093 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 P1093 GMC code?

Need more information on how to fix the P1093 GMC code? Get Access to Factory Service Manuals

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 P1093 GMC Code

1. What are the common symptoms of OBDII code P1093 GMC (Fuel Rail Pressure Low During Power Enrichment)?

The common symptoms include engine misfires, rough idling, loss of power, and hesitation during acceleration.

2. What are the possible causes of OBDII code P1093 GMC?

Possible causes include a faulty fuel pump, clogged fuel filter, fuel pressure regulator issues, or a fuel injector problem.

3. How can I diagnose OBDII code P1093 GMC?

Diagnosis typically involves checking the fuel pressure using a gauge, inspecting the fuel pump, fuel filter, and fuel injectors for any issues, and scanning for any other related trouble codes.

4. Can a dirty or clogged fuel filter trigger OBDII code P1093 GMC?

Yes, a dirty or clogged fuel filter can restrict fuel flow, leading to low fuel rail pressure and triggering the P1093 code.

5. What are some repair tips for fixing OBDII code P1093 GMC?

Repair tips may include replacing the fuel filter, testing and potentially replacing the fuel pump, checking and cleaning the fuel injectors, and ensuring proper fuel pressure regulation.

6. Is it safe to continue driving with OBDII code P1093 GMC present?

It is not recommended to continue driving with this code present, as it can lead to potential engine damage and decreased performance.

7. Can weather conditions affect the triggering of OBDII code P1093 GMC?

Extreme weather conditions, such as very cold temperatures, can sometimes affect fuel pressure and contribute to triggering this code.

8. How long does it typically take to repair OBDII code P1093 GMC?

The repair time can vary depending on the exact cause of the issue, but it may take a few hours to a full day to diagnose and fix the problem.

9. Will resetting the OBDII system clear OBDII code P1093 GMC?

Resetting the system may temporarily clear the code, but it will likely reappear if the underlying issue causing low fuel rail pressure is not addressed.

10. How much does it cost to repair OBDII code P1093 GMC?

The cost of repair can vary depending on the specific repairs needed, but it may range from a few hundred to over a thousand dollars, including parts and labor.