AutoCodes – Generic – P12B6

P12B6 Code - Cylinder 2 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: P12B6 indicates Cylinder 2 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 4,763

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 P12B6 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 P12B6 - Cylinder 2 Injection Timing Advance - AutoCodes.com — P12B6 Code - Cylinder 2 Injection Timing Advance

What does this mean?

What are the Possible Causes of the DTC P12B6?

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 P12B6?

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 P12B6 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 P12B6 code?

Need more information on how to fix the P12B6 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P12B6 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P12B6 Chevrolet — Cylinder 2 Injection Timing Advance
P12B6 GMC — Cylinder 2 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 P12B6 Code

1. What are the common symptoms of OBDII code P12B6 (Cylinder 2 Injection Timing Advance)?

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

2. What are the possible causes of OBDII code P12B6?

- The code P12B6 may be triggered by issues such as faulty fuel injectors, a malfunctioning timing chain, damaged wiring, or a problem with the engine control module (ECM).

3. How can I diagnose the cause of OBDII code P12B6?

- Diagnosis typically involves using a scan tool to read the code, checking the cylinder 2 fuel injector, inspecting the timing chain, and testing the wiring and connections related to cylinder 2 injection timing.

4. Can I continue driving with OBDII code P12B6 present?

- It is not recommended to continue driving with this code present, as it can lead to further engine damage and potentially unsafe driving conditions.

5. How can I repair OBDII code P12B6?

- Repair options may include replacing the faulty fuel injector, repairing or replacing the timing chain, addressing any wiring issues, or reprogramming the ECM.

6. Are there any DIY tips for addressing OBDII code P12B6?

- While some basic diagnostics can be done at home, it is recommended to consult a professional mechanic for a proper diagnosis and repair of OBDII code P12B6.

7. Can a dirty fuel system cause OBDII code P12B6 to appear?

- Yes, a dirty fuel system can potentially lead to issues with cylinder 2 injection timing advance, triggering OBDII code P12B6.

8. Is it safe to reset the OBDII code P12B6 without addressing the underlying issue?

- Resetting the code without addressing the underlying problem may temporarily turn off the check engine light but will not fix the root cause of the issue, potentially leading to further problems down the line.

9. How long does it typically take to repair OBDII code P12B6?

- The repair time for OBDII code P12B6 can vary depending on the exact cause of the issue, but it may take a few hours to a full day to diagnose and repair the problem.

10. Can a faulty ECM be the sole reason for OBDII code P12B6?

- While a faulty ECM can contribute to the triggering of OBDII code P12B6, it is essential to thoroughly diagnose other potential causes such as fuel injector issues or timing chain problems before assuming the ECM is the sole reason.