AutoCodes – Generic – P158B

P158B Code - Idle Air Control Actuator 1

Quick Answer

The Engine Control Module (ECM) monitors the Idle Air Control Actuator 1. Common causes include Faulty Idle Air Control Actuator, Idle Air Control Actuator harness is open or shorted, Idle Air Control Actuator 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: P158B indicates Idle Air Control Actuator 1.
Common causes: Common causes include Faulty Idle Air Control Actuator, Idle Air Control Actuator harness is open or shorted, Idle Air Control Actuator 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 5,322

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 01, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P158B Description

The Engine Control Module (ECM) monitors the Idle Air Control Actuator 1. The ECM sets the OBDII code when the Idle Air Control Actuator 1 is not to factory specifications.

OBDII Code P158B - Idle Air Control Actuator 1 - AutoCodes.com — P158B Code - Idle Air Control Actuator 1

What does this mean?

What are the Possible Causes of the DTC P158B?

Faulty Idle Air Control Actuator
Idle Air Control Actuator harness is open or shorted
Idle Air Control Actuator circuit poor electrical connection

How to Fix the DTC P158B?

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 P158B 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 P158B code?

Need more information on how to fix the P158B code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P158B code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P158B BMW — Idle Air Control Actuator 1
P158B MINI — Idle Air Control Actuator 1

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 P158B Code

1. What are the common symptoms of OBDII code P158B (Idle Air Control Actuator 1)?

- Common symptoms include rough idling, stalling at idle, decreased fuel efficiency, and potential engine misfires.

2. What can cause OBDII code P158B to trigger?

- This code is typically triggered by a faulty idle air control actuator, wiring issues, or a malfunction in the engine control module (ECM).

3. How can I diagnose the cause of OBDII code P158B?

- Diagnosing the issue may involve checking the idle air control actuator for proper operation, inspecting the wiring for damage, and using a scan tool to monitor the ECM signals.

4. Can a dirty throttle body cause OBDII code P158B?

- Yes, a dirty throttle body can restrict airflow and cause issues with idle control, potentially leading to the triggering of code P158B.

5. What are some repair tips for addressing OBDII code P158B?

- Repair tips may include cleaning or replacing the idle air control actuator, checking and repairing any damaged wiring, and ensuring proper connection to the ECM.

6. Is it safe to continue driving with OBDII code P158B present?

- While the vehicle may still be drivable with this code, it is not recommended to ignore it as it can lead to further engine performance issues if left unresolved.

7. Can resetting the ECM clear OBDII code P158B?

- Resetting the ECM may temporarily clear the code, but if the underlying issue is not addressed, the code is likely to reappear once the problem resurfaces.

8. How much does it typically cost to repair OBDII code P158B?

- The cost of repairing this code can vary depending on the specific cause, but it may range from $100 to $500 or more, including parts and labor.

9. Will OBDII code P158B cause a vehicle to fail an emissions test?

- Yes, this code can cause a vehicle to fail an emissions test due to its impact on engine performance and emissions control systems.

10. Can a DIY enthusiast fix OBDII code P158B, or is it best left to professionals?

- Depending on the level of expertise and access to tools, some DIY enthusiasts may be able to address the underlying issues causing this code. However, for more complex diagnostics and repairs, it is recommended to seek professional assistance.