AutoCodes – GMC – P12C0 GMC

P12C0 GMC Code - Cylinder 7 Injection Timing Advance

Quick Answer

The Engine Control Module (ECM) has the ability to learn injector timing performance. Common causes include Contaminated or improper fuel quality, Worn base engine components or differences in cylinder compression, Faulty Fuel Injector. 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: P12C0 GMC indicates Cylinder 7 Injection Timing Advance.
Common causes: Common causes include Contaminated or improper fuel quality, Worn base engine components or differences in cylinder compression, Faulty Fuel Injector.
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 1,296

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 Sep 11, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P12C0 GMC Description

The Engine Control Module (ECM) has the ability to learn injector timing performance. With the engine at operating temperature and in closed throttle decel 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 (CPS). The ECM will run this diagnostic under three different fuel rail pressures for each injector. The ECM will adjust the timing of fuel delivered by each injector to obtain the desired RPM increase. The ECM stores the injector timing value required to increase the crankshaft speed by the desired RPM. If the ECM cannot control an increase in RPM for a given injector the appropriate code will set for that injector.

OBDII Code P12C0 GMC - Cylinder 7 Injection Timing Advance - AutoCodes.com — P12C0 GMC Code - Cylinder 7 Injection Timing Advance

What does this mean?

What are the Possible Causes of the DTC P12C0 GMC?

Contaminated or improper fuel quality
Worn base engine components or differences in cylinder compression
Faulty Fuel Injector
Fuel Injector harness is open or shorted
Fuel Injector circuit poor electrical connection

How to Fix the DTC P12C0 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 P12C0 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 P12C0 GMC 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 P12C0 GMC Code

1. What are the common symptoms of OBDII code P12C0 GMC (Cylinder 7 Injection Timing Advance)?

- Common symptoms include engine misfires, rough idling, decreased fuel efficiency, and potential engine stalling.

2. What are the possible causes of OBDII code P12C0 GMC?

- The code may be triggered by issues such as a faulty fuel injector, a clogged fuel filter, a problem with the fuel pump, or a malfunctioning engine control module (ECM).

3. How can I diagnose the source of OBDII code P12C0 GMC?

- Diagnosing the code typically involves using an OBDII scanner to read the code, conducting a visual inspection of the fuel system components, and performing tests on the fuel injector and related components.

4. Can a dirty fuel system cause OBDII code P12C0 GMC to appear?

- Yes, a dirty fuel system can contribute to the triggering of this code, as it may affect the proper fuel delivery to the cylinder, leading to timing advance issues.

5. How can I repair OBDII code P12C0 GMC related to Cylinder 7 Injection Timing Advance?

- Repair options may include cleaning or replacing the fuel injector, replacing the fuel filter, checking and potentially replacing the fuel pump, and ensuring proper fuel system maintenance.

6. Is it safe to continue driving with OBDII code P12C0 GMC active?

- It is not recommended to continue driving with this code active, as it can lead to further engine damage and potential safety hazards due to rough running conditions.

7. Can a DIY enthusiast fix OBDII code P12C0 GMC on their own?

- Depending on the individual's skill level and access to tools, some DIY enthusiasts may be able to address this code by following proper diagnostic procedures and repair instructions.

8. Will resetting the OBDII system clear OBDII code P12C0 GMC permanently?

- Resetting the OBDII system may temporarily clear the code, but if the underlying issue causing the code is not addressed, it is likely to reappear after some driving cycles.

9. How can a professional mechanic assist in resolving OBDII code P12C0 GMC?

- A professional mechanic can conduct a thorough diagnosis, perform advanced tests on the fuel system, and provide expert repair solutions to effectively resolve the Cylinder 7 Injection Timing Advance issue.

10. Are there any recalls or technical service bulletins related to OBDII code P12C0 GMC?

- It is recommended to check with the manufacturer or authorized service centers for any recalls or technical service bulletins related to this specific OBDII code to ensure proper resolution.