370z Common Issues: Idle Learning

Symptom

Unstable idle and p0300 Misfire Codes.  Sometimes this can occur of the throttles are not correctly balanced.  In a 2 throttle system it's important that the computer knows what an equal amount of air is between the two throttles particularly at idle.

As a result of an imbalance the engine idle can feel rough and be unstable, during driving you may experience P0300 for random cylinder misfire, you may also see the Fuel Trim Short Term are unbalanced from side to side.

The Fix

This can be fixed using the ECM tool feature called Idle Learning.

1. Connect to the ECU using your vehicle interface and software.
   
   
2. Detect the vehicle
   
   
3. Select the option for "ECM Tools"
   
   
4. First Reset the ECU and wait for that to finish.
   
   
5. Now start the car and allow it to come up to temperature.  The doors and hood should be shut as well.
   
   
6. Choose idle learning.
   
   
7. Wait for the process to complete.  During this time the engine will make small fluctuations to the throttle blades and look at the resulting MAF values to determine what is an equal value for both banks.
   
   
8. Once it's done you can turn off the car and disconnect your cable.
   
   
9. You're all done!