AutoCodes – GMC – P0412 GMC

P0412 GMC Code - Secondary Air Injection Solenoid Relay Control Circuit

Quick Answer

The Powertrain Control Module (PCM) controls the relay by grounding the control circuit via an internal switch called a driver. Common causes include Faulty Air Pump inoperative, Air bypass solenoid harness is open or shorted, Air bypass solenoid circuit poor electrical connection. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means: P0412 GMC indicates Secondary Air Injection Solenoid Relay Control Circuit.
Common causes: Common causes include Faulty Air Pump inoperative, Air bypass solenoid harness is open or shorted, Air bypass solenoid circuit poor electrical connection.
Severity: Moderate - service should be scheduled soon.
Can I drive?: The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

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Code Popularity 5,051

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0412 GMC Description

The Powertrain Control Module (PCM) controls the relay by grounding the control circuit via an internal switch called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line which the PCM monitors. When the PCM commands a component ON, the voltage of the control circuit should be low (near 0 volts). When the PCM commands the control circuit to a component OFF, the voltage potential of the circuit should be high (near the battery voltage).
The relay controls the high current flow to the AIR injection pump integral bypass valve. This allows the PCM driver to only have to control the relatively low current used by the relay.

OBDII Code P0412 GMC - Secondary Air Injection Solenoid Relay Control Circuit - AutoCodes.com — P0412 GMC Code - Secondary Air Injection Solenoid Relay Control Circuit

What does this mean?

What are the Possible Causes of the DTC P0412 GMC?

Faulty Air Pump inoperative
Air bypass solenoid harness is open or shorted
Air bypass solenoid circuit poor electrical connection

How to Fix the DTC P0412 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 P0412 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.

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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 P0412 GMC Code

1. What are the common symptoms of OBDII code P0412 in a GMC vehicle?

- Common symptoms include illuminated Check Engine Light, rough idling, decreased engine performance, and potential emissions issues.

2. What does the OBDII code P0412 GMC indicate?

- The code P0412 indicates a malfunction in the Secondary Air Injection Solenoid Relay Control Circuit.

3. What are some possible causes of OBDII code P0412 in a GMC vehicle?

- Possible causes include a faulty secondary air injection solenoid relay, damaged wiring or connectors in the circuit, or a malfunctioning PCM.

4. How can I diagnose the cause of OBDII code P0412 in my GMC vehicle?

- A thorough inspection of the secondary air injection system, including the solenoid relay and its circuitry, is recommended. Checking for damaged wires or connectors and testing the relay's functionality can help pinpoint the issue.

5. Can I continue driving my GMC vehicle with OBDII code P0412?

- It is not recommended to drive with this code unresolved, as it may lead to further damage to the emissions system and affect the vehicle's performance.

6. How can I repair OBDII code P0412 in my GMC vehicle?

- Repair may involve replacing the faulty secondary air injection solenoid relay, repairing damaged wiring or connectors, or reprogramming the PCM if necessary.

7. Is it possible to reset the Check Engine Light caused by OBDII code P0412 in a GMC vehicle?

- Resetting the Check Engine Light can be done using an OBDII scanner after addressing the underlying issue triggering the code.

8. Are there any DIY tips for troubleshooting OBDII code P0412 in a GMC vehicle?

- DIY tips include visually inspecting the relay and circuit for any visible damage, checking for loose connections, and ensuring proper grounding of the components.

9. How much does it typically cost to repair OBDII code P0412 in a GMC vehicle?

- Repair costs can vary depending on the specific cause of the code, but it may range from $100 to $300 for parts and labor.

10. Can a mechanic help me with diagnosing and repairing OBDII code P0412 in my GMC vehicle?

- Yes, a qualified mechanic with experience in diagnosing and repairing automotive electrical systems can assist in resolving OBDII code P0412 in your GMC vehicle.