AutoCodes – Generic – P154A

P154A Code - Intake Air Heater Feedback Circuit

Quick Answer

The Intake Air Heater (IAH) is located in the air inlet tube and is used to warm the incoming air to aid in starting the engine and for proper cylinder combustion. Common causes include Faulty Intake Air Heater, Intake Air Heater harness is open or shorted, Intake Air 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: P154A indicates Intake Air Heater Feedback Circuit.
Common causes: Common causes include Faulty Intake Air Heater, Intake Air Heater harness is open or shorted, Intake Air 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 12,063

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Jan 01, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P154A Description

The Intake Air Heater (IAH) is located in the air inlet tube and is used to warm the incoming air to aid in starting the engine and for proper cylinder combustion. The Glow Plug Control Module (GPCM) will command the IAH on when the engine coolant temperature is below 40°C (104°F). Power to the IAH is supplied by the battery positive voltage circuit. The IAH is connected to the GPCM by the following circuits. If there is a fault on any of these circuits a DTC will set.
- The IAH temperature signal circuit
- The IAH command 1 circuit
- The IAH command 2 circuit
- The IAH voltage signal circuit
- The IAH current signal circuit
- The IAH feedback signal circuit

OBDII Code P154A - Intake Air Heater Feedback Circuit - AutoCodes.com — P154A Code - Intake Air Heater Feedback Circuit

What does this mean?

What are the Possible Causes of the DTC P154A?

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

How to Fix the DTC P154A?

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 P154A 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 P154A code?

Need more information on how to fix the P154A code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P154A code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P154A Chevrolet — Intake Air Heater Feedback Circuit
P154A GMC — Intake Air Heater Feedback Circuit

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 P154A Code

What does the OBDII code P154A mean?

1. The P154A code indicates an issue with the Intake Air Heater Feedback Circuit, which monitors the performance of the air heater system in diesel engines. 2.

What are the common symptoms of the P154A code?

Symptoms may include difficulty starting the engine in cold weather, reduced engine performance, and the check engine light illuminating. 3.

What causes the P154A code to appear?

Common causes include a faulty intake air heater, damaged wiring or connectors in the feedback circuit, or a malfunctioning engine control module (ECM). 4.

Can I drive with the P154A code active?

While the vehicle may still be drivable, it could experience poor cold-weather starting and reduced fuel efficiency. Prompt diagnosis and repair are recommended. 5.

How do you diagnose the P154A code?

Diagnosis involves inspecting the intake air heater, checking for damaged or corroded wiring, testing the feedback circuit, and verifying operation of the ECM using a scan tool. 6.

What repairs can fix the P154A code?

Repairs may include replacing the intake air heater, repairing or replacing damaged wiring, cleaning corroded connectors, or reprogramming or replacing the ECM. 7.

How much does it cost to fix the P154A code?

Repair costs vary but typically range from $150 to $500, depending on whether the issue is with the heater, wiring, or ECM. 8.

Can a dirty air filter cause the P154A code?

No, a dirty air filter does not directly cause this code. The issue is specific to the intake air heater feedback circuit. 9.

Will clearing the code fix the problem permanently?

No, clearing the code will only reset the check engine light temporarily. The underlying issue must be repaired to prevent the code from returning. 10.

Is the P154A code specific to diesel engines?

Yes, this code is typically found in diesel engines that use an intake air heater to aid in cold-weather starting.