AutoCodes – GMC – P2318 GMC

P2318 GMC Code - Ignition Coil 7 Control Circuit Low Voltage

Quick Answer

The ignition system on this engine uses ignition coils with integrated power transistors. Common causes include Faulty Ignition Coil 7, Ignition Coil 7 harness is open or shorted, Ignition Coil 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: P2318 GMC indicates Ignition Coil 7 Control Circuit Low Voltage.
Common causes: Common causes include Faulty Ignition Coil 7, Ignition Coil 7 harness is open or shorted, Ignition Coil 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 356

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 31, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P2318 GMC Description

The ignition system on this engine uses ignition coils with integrated power transistors. The Engine Control Module (ECM) controls the spark event for each cylinder through individual ignition coil control circuits. When the ECM commands the ignition control circuit On, electrical current flows through the primary winding of the ignition coil, creating a magnetic field. When a spark event is requested, the ECM commands the ignition control circuit Off, interrupting current flow through the primary winding. The collapsing magnetic field created by the primary winding induces a high voltage in the secondary winding, which is connected to the spark plugs. The Diagnostic Trouble Code (DTC) will be set when the control circuit commanded by the ECM state does not match the actual state.

OBDII Code P2318 GMC - Ignition Coil 7 Control Circuit Low Voltage - AutoCodes.com — P2318 GMC Code - Ignition Coil 7 Control Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P2318 GMC?

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

How to Fix the DTC P2318 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 P2318 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 P2318 GMC code?

Need more information on how to fix the P2318 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P2318 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P2318 2014 GMC Sierra — Ignition Coil 7 Control Circuit Low Voltage
P2318 2015 GMC Sierra — Ignition Coil 7 Control Circuit Low Voltage
P2318 2016 GMC Sierra — Ignition Coil 7 Control Circuit Low Voltage
P2318 2017 GMC Sierra — Ignition Coil 7 Control Circuit Low Voltage
P2318 2018 GMC Sierra — Ignition Coil 7 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 P2318 GMC Code

1. What are the common symptoms of OBDII code P2318 GMC?

- Common symptoms include rough idling, engine misfires, loss of power, and illuminated check engine light.

2. What can cause the ignition coil 7 control circuit low voltage error code?

- Possible causes include a faulty ignition coil, damaged wiring or connectors, a failed ignition control module, or issues with the PCM.

3. How can I diagnose the issue related to code P2318 GMC?

- You can use a diagnostic scanner to pinpoint the exact cause of the problem by checking for related codes, conducting a visual inspection of wiring and connectors, and performing circuit tests.

4. Can a DIY enthusiast repair the ignition coil 7 control circuit low voltage issue?

- Repairing this issue may require some expertise, as it involves electrical components. It's recommended to consult a professional mechanic for proper diagnosis and repair.

5. What are some repair tips for resolving OBDII code P2318 GMC?

- Repair tips may include replacing the faulty ignition coil, repairing damaged wiring or connectors, ensuring proper grounding, and checking the ignition control module's functionality.

6. Is it safe to continue driving with the ignition coil 7 control circuit low voltage error code?

- It is not recommended to drive with this code present, as it can lead to further damage to the engine and emissions system. It's best to address the issue promptly.

7. How much does it typically cost to repair OBDII code P2318 GMC?

- Repair costs can vary depending on the extent of the issue and the specific components that need to be replaced. It's advisable to get a professional estimate for an accurate cost assessment.

8. Can a bad spark plug cause code P2318 GMC to trigger?

- While a bad spark plug can contribute to ignition issues, code P2318 GMC specifically relates to the control circuit of ignition coil 7. It's important to address the root cause of the error code.

9. Will resetting the check engine light make OBDII code P2318 GMC disappear?

- Resetting the check engine light may temporarily clear the code, but if the underlying issue is not addressed, the code is likely to reappear. It's crucial to diagnose and repair the problem.

10. How long does it typically take to repair the ignition coil 7 control circuit low voltage issue?

- The repair time can vary based on the complexity of the problem and the availability of parts. A mechanic can provide an estimated repair time after diagnosing the issue.