Engine-CodesInfiniti – P1148 Infiniti

P1148 Infiniti Code - Closed Loop Control Function Bank 1

Quick Answer

The P1148 code in Infiniti vehicles refers to an issue with the Closed Loop Control Function in Bank 1 of the engine. Common causes include Faulty oxygen sensor, Vacuum leaks in the intake system, Issues with the fuel injectors. 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
P1148 Infiniti indicates Closed Loop Control Function Bank 1.
Common causes
Common causes include Faulty oxygen sensor, Vacuum leaks in the intake system, Issues with the fuel injectors.
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.
Table of contents Created and updated by William Orellana on Aug 30, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P1148 Infiniti Description

The P1148 code in Infiniti vehicles refers to an issue with the Closed Loop Control Function in Bank 1 of the engine. In simple terms, the closed-loop control system is responsible for adjusting the air-fuel mixture in the engine to ensure optimal combustion and performance. When this system malfunctions in Bank 1, it can lead to a variety of issues that affect the vehicle's overall performance and efficiency.

OBDII Code P1148 Infiniti - Closed Loop Control Function Bank 1
P1148 Infiniti Code - Closed Loop Control Function Bank 1

Common Causes of P1148 Infiniti

  1. Faulty oxygen sensor
  2. Vacuum leaks in the intake system
  3. Issues with the fuel injectors
  4. Wiring or electrical problems in the closed-loop control system
  5. Exhaust system leaks or damage

Symptoms of P1148 Infiniti

  1. Decreased fuel efficiency
  2. Engine running rough or misfiring
  3. Check Engine Light illuminated
  4. Reduced engine power
  5. Increased emissions output

How to Fix P1148 Infiniti

  1. Diagnose the specific cause of the issue by performing a thorough inspection of the oxygen sensors, intake system, fuel injectors, and wiring.
  2. Replace any faulty oxygen sensors or damaged components in the closed-loop control system.
  3. Repair any vacuum leaks in the intake system and ensure proper sealing.
  4. Clear the error code and reset the engine control module.
  5. Test drive the vehicle to ensure the issue has been resolved and the code does not return.

Cost to Fix P1148 Infiniti

The cost of repairing a P1148 code in an Infiniti vehicle can vary depending on the specific cause of the issue. On average, the repair cost can range from $200 to $500, including parts and labor. However, it's important to note that diagnostic time and labor rates at auto repair shops can vary, so it's advisable to consult with a professional technician for a more accurate estimate.

Tech Notes for P1148 Infiniti

There is a Factory Service Bulletin for the following Infiniti models:
2004-2005 Infiniti FX35 2WD
2004-2005 Infiniti FX35 4WD
2004-2005 Infiniti G35 Sedan 2WD
2004-2005 Infiniti G35 Sedan 4WD
Infiniti Factory Service Bulletin OBDII Code P1148

The bulletin suggests reprogramming the Engine Control Module (ECM) first before replacing any parts.

Need more information about the P1148 Infiniti code?

Need more information on how to fix the P1148 Infiniti code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1148 Infiniti code diagnosed by a professional: Find a repair shop in your area

Information for Specific Infiniti Models

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 P1148 Infiniti Code

What does the OBD-II code P1148 mean for an Infiniti?

The P1148 code indicates a problem with the closed-loop control function for Bank 1, often caused by issues with the air-fuel ratio sensor or its circuit.

What are the common symptoms of the P1148 code in an Infiniti?

Symptoms may include the check engine light turning on, decreased fuel efficiency, rough idling, or poor engine performance.

What causes the P1148 code in an Infiniti vehicle?

Common causes include a faulty air-fuel ratio (A/F) sensor, damaged wiring or connectors, a malfunctioning engine control module (ECM), or exhaust system leaks.

How can I diagnose the P1148 code in my Infiniti?

Start by checking the air-fuel ratio sensor and its wiring for damage, inspecting for exhaust leaks, and using a scan tool to monitor sensor data.

Can I drive my Infiniti with the P1148 code active?

Driving with this code is not recommended as it may lead to reduced fuel efficiency, increased emissions, and potential damage to the catalytic converter.

How is the P1148 code repaired in an Infiniti?

Repairs may include replacing the air-fuel ratio sensor, repairing wiring or connector issues, fixing exhaust leaks, or reprogramming the ECM if necessary.

How much does it cost to fix the P1148 code on an Infiniti?

Costs can vary but typically range from $200 to $500 for parts and labor, depending on whether the air-fuel ratio sensor or other components need replacement.

Can a dirty air filter cause the P1148 code on an Infiniti?

While unlikely, a severely clogged air filter can affect engine performance and air-fuel ratio, potentially contributing to this code.

What tools are needed to fix the P1148 code on an Infiniti?

Essential tools include an OBD-II scanner, a multimeter for electrical testing, and basic hand tools to inspect and replace components.

Does the P1148 code always mean the air-fuel ratio sensor is bad?

No, the code can also be triggered by wiring issues, exhaust leaks, or ECM problems, so thorough diagnosis is essential before replacing parts.

Discuss the causes and fixes for P1148 Infiniti OBDII Code

Code P1148 Infiniti comments

No comments found for this page.