AutoCodes – Generic – P12C2

P12C2 Code - Cylinder 8 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: P12C2 indicates Cylinder 8 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 2,305

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 P12C2 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 P12C2 - Cylinder 8 Injection Timing Advance - AutoCodes.com — P12C2 Code - Cylinder 8 Injection Timing Advance

What does this mean?

What are the Possible Causes of the DTC P12C2?

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 P12C2?

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 P12C2 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 P12C2 code?

Need more information on how to fix the P12C2 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P12C2 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P12C2 Chevrolet — Cylinder 8 Injection Timing Advance
P12C2 GMC — Cylinder 8 Injection Timing Advance

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 P12C2 Code

1. What are the common symptoms of OBDII code P12C2 (Cylinder 8 Injection Timing Advance)?

- Common symptoms include engine misfires, rough idle, decreased fuel efficiency, and potentially a noticeable lack of power during acceleration.

2. What are the typical causes of OBDII code P12C2?

- The common causes of this code are faulty fuel injectors, issues with the fuel injection timing system, wiring problems, or a malfunctioning engine control module (ECM).

3. How can I diagnose the issue related to OBDII code P12C2?

- Diagnosis typically involves using an OBDII scanner to read the code and then conducting further testing to pinpoint the exact cause, such as checking fuel injector operation and inspecting wiring connections.

4. What are some repair tips for resolving OBDII code P12C2?

- Repair options may include replacing the faulty fuel injector, repairing wiring connections, recalibrating the fuel injection timing system, or reprogramming the engine control module.

5. Can driving with OBDII code P12C2 cause further damage to my vehicle?

- Continuing to drive with this code may lead to decreased engine performance, increased fuel consumption, and potential damage to the catalytic converter over time if left unresolved.

6. Is it safe to reset the OBDII code P12C2 using a diagnostic tool?

- While resetting the code may temporarily clear the warning light, it is important to address the underlying issue causing the code to prevent further engine problems.

7. How much does it typically cost to repair OBDII code P12C2 at a mechanic?

- The cost of repair can vary depending on the exact cause of the code, but it may range from $200 to $800 or more, including parts and labor.

8. Are there any preventive maintenance measures to avoid OBDII code P12C2 in the future?

- Regularly servicing your vehicle, using high-quality fuel, and promptly addressing any engine performance issues can help prevent the occurrence of this code.

9. Can OBDII code P12C2 be triggered by a faulty sensor?

- While a faulty sensor could potentially cause issues with fuel injection timing, it is more commonly associated with fuel injector or ECM problems.

10. How urgent is it to address OBDII code P12C2 once it appears?

- It is recommended to address the underlying issue causing the code as soon as possible to prevent further damage to the engine and ensure optimal vehicle performance.