AutoCodes – GMC – P00C9 GMC

P00C9 GMC Code - Fuel Pressure Regulator High Control Circuit Low Voltage

Quick Answer

High-pressure fuel is regulated by the high-pressure fuel pump actuator, which is a part of the high-pressure fuel pump. Common causes include Faulty High-Pressure Fuel Pump, High-Pressure Fuel Pump harness is open or shorted, High-Pressure Fuel Pump electrical circuit poor 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: P00C9 GMC indicates Fuel Pressure Regulator High Control Circuit Low Voltage.
Common causes: Common causes include Faulty High-Pressure Fuel Pump, High-Pressure Fuel Pump harness is open or shorted, High-Pressure Fuel Pump electrical circuit poor 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 2,247

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 May 16, 2022

Description
Possible Causes
How To Fix
Tech Notes ▶
Cost to Diagnose
FAQs
Comments
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Code P00C9 GMC Description

High-pressure fuel is regulated by the high-pressure fuel pump actuator, which is a part of the high-pressure fuel pump. The high-pressure fuel pump actuator is a solenoid valve. The Engine Control Module (ECM) provides battery voltage on the actuator high control circuit and ground on the actuator low control circuit. Both circuits are controlled through output drivers within the ECM. When deactivated, both drivers are disabled. When activated, the high control circuit driver energizes the high-pressure fuel pump actuator, and the low control circuit driver Pulse-Width Modulates (PWM) the low control circuit to the ground. The ECM monitors the voltage on the circuits to detect a failure. The Diagnostic Trouble Code (DTC) will set if the ECM detects a short to ground in the high-pressure fuel pump actuator high control circuit.

OBDII Code P00C9 GMC - Fuel Pressure Regulator High Control Circuit Low Voltage - AutoCodes.com — P00C9 GMC Code - Fuel Pressure Regulator High Control Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P00C9 GMC?

Faulty High-Pressure Fuel Pump
High-Pressure Fuel Pump harness is open or shorted
High-Pressure Fuel Pump electrical circuit poor connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P00C9 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

User Submitted Video

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P00C9 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 P00C9 GMC code?

Need more information on how to fix the P00C9 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

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Information for Specific GMC Models

P00C9 2014 GMC Sierra — Fuel Pressure Regulator High Control Circuit Low Voltage
P00C9 2015 GMC Sierra — Fuel Pressure Regulator High Control Circuit Low Voltage
P00C9 2016 GMC Sierra — Fuel Pressure Regulator High Control Circuit Low Voltage
P00C9 2017 GMC Sierra — Fuel Pressure Regulator High Control Circuit Low Voltage
P00C9 2018 GMC Sierra — Fuel Pressure Regulator High Control Circuit Low Voltage

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 P00C9 GMC Code

1. What are common symptoms of OBDII code P00C9 in a GMC vehicle?

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

2. What could cause the OBDII code P00C9 to trigger in a GMC vehicle?

- The code P00C9 typically triggers due to a fault in the fuel pressure regulator control circuit, resulting in low voltage.

3. How serious is the OBDII code P00C9 in a GMC vehicle?

- The code P00C9 should be addressed promptly to prevent potential damage to the engine and ensure optimal vehicle performance.

4. What are some DIY repair tips for resolving the OBDII code P00C9 in a GMC vehicle?

- DIY repair tips include checking the wiring and connections related to the fuel pressure regulator, testing the regulator for proper function, and clearing the code with an OBDII scanner.

5. Can a faulty fuel pressure regulator cause the OBDII code P00C9 in a GMC vehicle?

- Yes, a malfunctioning fuel pressure regulator can cause the code P00C9 by disrupting the control circuit and leading to low voltage readings.

6. Is it safe to continue driving with the OBDII code P00C9 illuminated in a GMC vehicle?

- It is not recommended to drive with the OBDII code P00C9 present, as it can affect the vehicle's performance and potentially cause further damage.

7. How can a mechanic diagnose the OBDII code P00C9 in a GMC vehicle?

- A mechanic can diagnose the code P00C9 by using an OBDII scanner to read the fault codes, testing the fuel pressure regulator and control circuit, and inspecting related components.

8. What are the typical repair costs associated with fixing the OBDII code P00C9 in a GMC vehicle?

- Repair costs for the OBDII code P00C9 can vary depending on the exact cause of the issue, but they may range from $200 to $500, including parts and labor.

9. Are there any preventive measures to avoid the OBDII code P00C9 in a GMC vehicle?

- Regular maintenance, such as fuel system inspections and timely replacements of fuel pressure components, can help prevent the occurrence of the OBDII code P00C9.

10. Can resetting the OBDII code P00C9 in a GMC vehicle make it go away permanently?

- Resetting the code may temporarily turn off the check engine light, but if the underlying issue is not addressed, the code is likely to reappear. It is crucial to diagnose and fix the root cause of the problem.