AutoCodes – GMC – P166C GMC

P166C GMC Code - Intake Air Heater Resistance

Quick Answer

The Engine Control Module (ECM) monitors the Intake Air (IA) Heater. Common causes include Faulty Intake Air (IA) Heater, Intake Air (IA) Heater harness is open or shorted, Intake Air (IA) Heater 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: P166C GMC indicates Intake Air Heater Resistance.
Common causes: Common causes include Faulty Intake Air (IA) Heater, Intake Air (IA) Heater harness is open or shorted, Intake Air (IA) Heater 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 1,482

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 Jan 06, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P166C GMC Description

The Engine Control Module (ECM) monitors the Intake Air (IA) Heater. The ECM sets the OBDII code when the Intake Air (IA) Heater is not to factory specifications.

OBDII Code P166C GMC - Intake Air Heater Resistance - AutoCodes.com — P166C GMC Code - Intake Air Heater Resistance

What does this mean?

What are the Possible Causes of the DTC P166C GMC?

Faulty Intake Air (IA) Heater
Intake Air (IA) Heater harness is open or shorted
Intake Air (IA) Heater circuit poor electrical connection

How to Fix the DTC P166C 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 P166C 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 P166C GMC code?

Need more information on how to fix the P166C GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P166C GMC code diagnosed by a professional: Find a repair shop in your area

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 P166C GMC Code

1. What are common symptoms of OBDII code P166C GMC related to Intake Air Heater Resistance?

The common symptoms include poor engine performance, rough idling, reduced fuel efficiency, and the illumination of the Check Engine Light.

2. What are the possible causes of OBDII code P166C GMC for Intake Air Heater Resistance?

The code may be triggered by a faulty intake air heater, damaged wiring or connectors, a blown fuse, or issues with the intake air temperature sensor.

3. How can I diagnose OBDII code P166C GMC for Intake Air Heater Resistance?

Diagnosis typically involves using an OBDII scanner to retrieve the code, checking the intake air heater system components for damage, and testing the resistance of the intake air heater.

4. Can I still drive my vehicle with OBDII code P166C GMC related to Intake Air Heater Resistance?

It is not recommended to drive the vehicle for an extended period with this code present, as it can lead to further damage and decreased engine performance.

5. How can I repair OBDII code P166C GMC for Intake Air Heater Resistance?

Repairing the issue involves replacing the faulty intake air heater, repairing or replacing damaged wiring or connectors, and ensuring proper connection of the intake air temperature sensor.

6. Are there any DIY tips for fixing OBDII code P166C GMC related to Intake Air Heater Resistance?

DIY tips include checking the fuse related to the intake air heater, inspecting the wiring for any visible damage, and cleaning the intake air heater system components.

7. Can a mechanic help me fix OBDII code P166C GMC for Intake Air Heater Resistance?

Yes, a qualified mechanic can diagnose the issue accurately, replace faulty components, and ensure proper functioning of the intake air heater system.

8. How much does it typically cost to repair OBDII code P166C GMC for Intake Air Heater Resistance?

The cost of repair can vary depending on the extent of the damage and the labor rates in your area, but it generally ranges from $200 to $500.

9. Will resetting the OBDII code P166C GMC make it go away permanently?

Simply resetting the code will not fix the underlying issue causing P166C GMC. It is essential to diagnose and repair the root cause to prevent the code from reoccurring.

10. Can a faulty intake air heater impact the overall performance of the vehicle?

Yes, a faulty intake air heater can negatively impact engine performance, fuel efficiency, and emissions, making it essential to address the issue promptly.