Engine-CodesChrysler – P1128 Chrysler

P1128 Chrysler Code - Closed Loop Fueling Not Achieved Bank 1

Quick Answer

The P1128 Chrysler code indicates that the closed-loop fuel control system on Bank 1 is not achieving the desired fuel mixture. Common causes include Faulty oxygen sensor, Vacuum leaks, Fuel system issues. 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
P1128 Chrysler indicates Closed Loop Fueling Not Achieved Bank 1.
Common causes
Common causes include Faulty oxygen sensor, Vacuum leaks, Fuel system issues.
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 19, 2024
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Code P1128 Chrysler Description

The P1128 Chrysler code indicates that the closed-loop fuel control system on Bank 1 is not achieving the desired fuel mixture. In a closed-loop system, the engine control module (ECM) uses information from oxygen sensors to adjust the air/fuel mixture to achieve optimal combustion. When this code is triggered, it means that the ECM is unable to achieve the correct fueling on Bank 1, which can lead to poor engine performance, reduced fuel efficiency, and increased emissions.

OBDII Code P1128 Chrysler - Closed Loop Fueling Not Achieved Bank 1
P1128 Chrysler Code - Closed Loop Fueling Not Achieved Bank 1

Common Causes of P1128 Chrysler

  1. Faulty oxygen sensor
  2. Vacuum leaks
  3. Fuel system issues
  4. Mass airflow sensor malfunction
  5. Exhaust system leaks

Symptoms of P1128 Chrysler

  1. Decreased fuel efficiency
  2. Rough idling or stalling
  3. Engine misfires
  4. Check Engine Light illuminated
  5. Poor acceleration

How to Fix P1128 Chrysler

  1. Diagnose the issue using a scan tool to pinpoint the exact cause of the problem.
  2. Inspect and test the oxygen sensor on Bank 1 to ensure it is functioning correctly.
  3. Check for vacuum leaks and repair or replace any damaged hoses.
  4. Inspect the fuel system for clogs or leaks and address any issues found.
  5. Test the mass airflow sensor and replace if necessary.

Cost to Fix P1128 Chrysler

The typical repair costs for addressing the P1128 Chrysler code can range from $200 to $500, including parts and labor. However, actual costs may vary depending on the specific diagnosis and repair needed, as well as labor rates at different auto repair shops. It's recommended to get a detailed estimate from a qualified mechanic before proceeding with the repair.

Tech Notes for P1128 Chrysler

Start by checking the battery charge and terminals, and alternator charging. If the battery and alternator are OK, the Totally Integrated Power Module may be damage.

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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 P1128 Chrysler Code

No Frequently Asked Questions about P1128 Chrysler Code found.

Discuss the causes and fixes for P1128 Chrysler OBDII Code

  • I really need help

  • What exactly is your problem what is the the model and year of your Chrysler.

  • tengo un CHRYSLER 300C 2006 5.7 acavo de cambiar aceite,bujias,filtro de aire, y me aparece este codigo que nose que pueda ser, el carro corre muy bien execto cuando voy a yegar a aser un alto el motor tiene un poco de vibrasion nose que es lo que pueda ser!

  • Primero inspeccione todas la connecciones y partes que quito para remover las bujias. Si todo esta bien, entoces le va a tener que cambiar el sensor de oxigeno.

  • my 2008 dodge grand caravan just shuts off unexplainably when idling smoothly it just stops it starts right back up and runs fine until the next time ,if I'm driving and it shuts off it just causes a momentary hitch. then keeps going.

  • Did you ever get help?

  • My 2008 Chrysler Town & Country is turning off when I come to a full stop. When driving it stalls and tugs. If I am stopped, when I press on the gas to go, it stalls. It doesn't do it all the time it happens once in a while. I notice it does it a lot more and tugs harder when it stalls when I use my A/C. I get the P0339 code. I have changed the Cram and Crank sensors. Then it gives me the P1128 code and the then it goes aways and gives me the P0339 code again. It's weird.

  • Unfortunately there are many things that could cause the engine to stall, both codes may come ON as a result of the engine stall, but may not be the cause. Next step is checking what is missing when the engine stall, could be fuel pressure, spark or air. You may need to install a fuel pressure gauge to check that.

  • ok, thanks. Will try.

  • Hi. We've been having the similar problem with our 2008 Dodge Grand Caravan. It stalls randomly but starts right back up. The codes p1128 and p0339 displayed. So far we've changed all plugs, wires, coil, crank sensor, cam sensor and after each change the service lights will go away but it will continue to stall randomly. Any ideas what it could be?

  • Hi. Did u find a solution to your problem?

  • Try changing the ignition switch (weird, but it was a problem with that!), had the same problem on my wife's jeep liberty and that solved it.

  • Any solution to the P1128 and P0339 codes?

  • Try fixing the P0339 code first.

    P0339 Chrysler - Crankshaft Position Sensor Intermittent

    Read more: http://www.autocodes.com/p0...

  • after more test than you could imagine, I fixed this problem by replacing the coil pack, 2007 Pacifica.
    the code P1128 accompanied along with P0339 (crank sensor- not needed) and P0300 (random misfire) and C121C (torque request signal denied) all corrected by changing the coil pack... I had also changed the 02 sensors and crank sensor with no result, the original problem was stalling,,, the engine ran great and would just die for no apparent reason, it died so often it was nearly un-driveable .

  • Great information Bob. Thank you for sharing!!!

  • I have a 2007 Chrysler 300 2.7. It drives smoothly

    . As soon as i slow down to a stop it starts to shake. The engine light is on and flashes then stops off and on.
    We have changes spark plugs, coils, manifold intake gasket, o2 sensor, canister purge valve. It is still having the problem. What else can it be??

  • For your model year the fuel injectors or the fuel pump are the more common cause of the problem. You could have a clogged fuel injectors. I recommend start by using a fuel injector cleaner additive and high octane fuel for a couple of days and monitor to see if that make any difference.