Why is idle relearn not working on your Nissan car? You are not the first to experience this problem. Other people have encountered it and have ways to go about it.
The most common causes of the Nissan idle relearn problem include stored DTCs, faulty vehicle components, and incorrect idle relearn procedures. Unless you resolve these issues, you will never perform this task successfully.
This article focuses on the causes and how to fix the Nissan idle not working problem. We will also outline the appropriate relearning procedure. Read on for detailed information.
What Is Idle Relearn On Nissan Vehicles?
Idle relearn on Nissan vehicles is a procedure for reprogramming the vehicle’s computer memory to idle at a specified speed or RPM. Without it, the car can rug arbitrarily, causing unnecessary engine wear and tear. Also, the engine will be less efficient. That leads to low mileage per gallon and excess carbon emissions. In other words, your vehicle cannot pass a smog test without a relearn.
A relearn procedure at idle is necessary after replacing or cleaning the electronic throttle body. Over time, this engine component can wear out or get dirty. Cleaning it is a long process that requires caution and the use of the right product to achieve it.
Other vehicles also need idle relearn after replacing the battery. Disconnecting the battery from the car can erase the data on the car’s computer about your driving habit. So, a relearn may also be necessary for such situations.
What Causes The Idle Relearn Not Working On Nissan?
The Nissan idle relearn may fail due to different reasons. Unless you check and resolve those issues, your every effort will be in vain. The following are the most common causes of failure:
Incorrect Preconditioning The Vehicle For The Relearn Procedure
The relearn procedure on Nissan vehicles can fail when you don’t precondition the car appropriately. The car computer aborts the process once you don’t meet the following conditions:
- The battery voltage at idle should be more than 12.9V.
- Engine coolant temperature should be between 70-95 degrees Celsius or 158-203 degrees Fahrenheit.
- The park or neutral position switch is ON.
- Ensure the electronic load switch is OFF – turn off the air conditioner, headlights, rear window defogger, and heated seats.
- Turn the steering wheel to a neutral position – a straight-ahead position.
- Transmission is in a full warm-up temperature – you may need to drive your vehicle for at least 10 minutes to achieve this.
Besides checking all conditions above, you should ensure there are no vacuum leaks by checking engine hoses, PVC system, oil dipstick, and filler cap seals for damage.
The high temperature in the engine compartment can take a toll on these plastic and rubber tubes. These are the most common causes of relearning failure. So, you have to check them to ensure they are in working order.
Do not attempt the Nissan idle relearn procedure if the check engine light is on. Use an OBD2 scanner to read any stored DTCS. If you find any code related to the mass airflow sensor, manifold absolute pressure, or incorrect idle speed, do not perform idle relearn. Resolve these issues before the relearn procedure.
Rough idling is one of the engine faults that will turn on the check engine light. You can never achieve a successful relearn if you don’t address this issue. You should diagnose the car to identify what causes the rough idling and resolve it.
The following are the common causes of rough engine idle:
- Dirty fuel injectors
- Faulty spark plugs, spark plug wires, and ignition coils
- Clogged or blocked air filter
- Jammed Positive Crankcase Ventilation (PVC) valve
- Damaged Exhaust Gas Recirculation (EGR) valve
- Faulty oxygen sensor
- Head gasket leak
- Fuel pump failure
- Dirty, clogged up, or malfunctioning electronic throttle body
Incorrect Idle Relearn Procedure
The Nissan idle relearn procedure requires caution and proper timing. If done incorrectly, failure is a guarantee. So, you should follow all the steps and track time appropriately. A stopwatch is necessary to time yourself during the relearning process.
How To Diagnose This Problem
Diagnosing the idle relearn problem in Nissan involves checking the possible causes and resolving any identified issues. Proceed as follows:
- Check that you meet all the vehicle preconditioning requirements and perform the idle relearn again. Also, you have to ensure you are using the appropriate procedure and timing everything correctly.
- Check for any possible causes of vacuum leaks. Ensure no physical damage on the engine hoses, oil dipstick, and filler cap seals before attempting idle relearning again.
- Check the vehicle for any faults that cause rough idling. You may need to diagnose all possible causes, one by one, to identify the culprit and resolve the problem.
- Diagnose the vehicle using an OBD2 scanner if the check engine light or service engine soon dashboard symbol is on. Resolve all DTCs related to mass airflow sensor, manifold absolute pressure, or incorrect idle speed.
How To Do A Nissan Idle Relearn Correctly
The Nissan idle relearn is a three-part procedure. You have to do Accelerator Pedal Released Position Learning, Throttle Valve Closed Position Learning, and Idle Air Volume Learning. Let’s outline the steps under each section.
Accelerator Pedal Released Position Learning:
- Do not depress the accelerator pedal.
- Turn the ignition key to the ON position for at least 2 seconds without starting the engine.
- Turn it back off for another 10 seconds.
- Turn the ignition key back ON for 2 seconds without starting the engine.
- Turn the key to the OFF position for 10 seconds. This step completes the first part of the idle relearn procedure.
Throttle Valve Closed Position Learning:
- Do not depress the accelerator pedal.
- Turn the ignition key to the ON position for 10 seconds without starting the engine.
- Turn the key back to the OFF position and listen for the throttle body producing a whining sound. The sound is sometimes not audible. So, believe that it is happening. Give it a few seconds before proceeding to the last part.
Idle Air Volume Learning:
- Start the engine and step on the accelerator to warm the engine to operating temperature with the vehicle in park and steering in a straight-ahead position. Also, turn off AC and other electrical consumers.
- Check the battery voltage at idle. It should read 12.9V or more.
- Let the vehicle reach the warm-up temperature. Stop the engine and turn the ignition key to the OFF position for 10 seconds.
- Do not depress the accelerator.
- Turn the ignition key to the ON position without starting the engine and wait for 3 seconds.
- Press the accelerator pedal down five times within 5 seconds and wait for another 7 seconds. AT this point, the check engine light should start flashing.
- Hold the accelerator pedal down for 20 seconds and release it after 3 seconds when the check engine light stops flashing.
- Start the engine and let it idle.
- Depress the accelerator to increase the engine’s RPM and observe if it settles to a constant idling speed each time you do that. The check engine light should also go off for a successful Nissan idle relearn.
Nissan car owners report idle relearn procedure not working. The problems may be incorrect relearning steps or faulty car components. If you run into the same issue, diagnose the possible causes and resolve them, as described in this article. Once done, you should successfully perform idle relearn.