The car is a 2010 sedan with 60000 miles. Firstly, it was only a P0106 error code, and I did not take care of it because I thought it is fine. Then, it becomes hard on idle (500~550 rpm). When I am waiting for the red light, it may pop out another SES code, which is the P2101, with VDC-off and slipping light on.
Took it to the dealer, the dealer can not diagnose what the problem is...
Any clue on the possible solution? Thanks.

 

A P2101 is defined by Infiniti as:
Bank 1 (passenger side) electric throttle control function does not operate properly.

Easy first steps:
• remove the rubber intake boot and check for anything that can prevent throttle body movement.
• check for any damage to the wire harness that connects to the throttle body
• unplug and plug in the throttle body wiring harness

To continue to troubleshoot you will need basic electricity skills and a multi-meter to check for voltages and continuity (resistance)

-OR-
You could take a gamble and replace the throttle body without troubleshooting and hope it works.

Here is a nice video that shows and explains the inside of the G37 throttle body;

 

Thanks for the info. I will bring it to the dealer and see what they can do...
BTW, are there any problems can be caused by the OBD reader? The last time I got the code, the technician told me keeping the OBD scaner plugged can lead to SES code...

 

I find that very hard (impossible?) to believe. Please ask the tech what the code it... I suspect they won't have an answer.

 

Try swapping left and right throttle bodys and see if code follows.

 

Good thought, but for some reason, the throttle bodies are wired differently.

On bank 1, pins 1+2 connect to the DC motor that moves the throttle body.
On bank 2, pins 1+2, connect to the throttle position sensor

 

I'm willing to bet that a thorough cleaning of the throttle bodies will help. The car is 10 years old. And if the dealer wasn't able to properly diagnose/repair the issue in the first place, and advised you to not leave the scan tool in, you might want to consider a new shop.

 

you could make wire extensions to connect to opposing side without having to take them out. Have you hooked up ohm meter to read each one at idle to see if readings

 

I have just got the call back from the dealer, they ask me to replace the throttle body for $1219... Is the repair cost reasonable?
BTW, is there any recommended aftermarket throttle body? Thanks a lot.

 

I have been to the dealer five times. The first time, I told them there are two codes in the car, but they only took care of the P0106 by conducting an ECU upgrade. However, the codes pop up again after couple days. So I went to them for the second time, since they didn't do a thorough check of what is going on in the car. They told me to replace the MAP sensor, and get it done during my third visit. For the forth, they told me the OBD reader I plugged in the car can cause various SES light (which is ridiculous obviously), so I get it unplugged and drive for one day until the SES light came up again when I was driving on the highway with 30 mph (traffics...). For the fifth visit, they want to charge me for another diagnose, which makes totally nonsense...
Just now, they got me the final diagnose result and ask me to replace the throttle body with $1219...

 

Thank you guys for the impressive suggestions, but I still decide to replace the passenger side throttle body, cause I really don't have the necessary gears and lacking the experience for the car stuff. I would like to find another shop for the replacement. Is there any recommended aftermarket throttle body I can use? The Infiniti parts are way too expensive. Also, is it okay to do it via YourMechanic.com?
Thanks.

 

The Infiniti part MSRP is $727 (from: https://parts.infinitiusa.com/p/Infi...119-JK20D.html)
It takes less than 30 minutes to replce it and then a "Idle air volume learning" needs to be done. (no special tools required)
So, I do think $1200 is way too much.

In my opinion as used throttle body (ebay, scrap yard) is better quality than any aftermarket.
There are a few on ebay right now for $20 - $70.

Did you check the throttle body wire harness for damage?

Your options as I see it:
• Purchase a used one from ebay, scrap yard, etc
• Change it yourself / Pay a local garage to change it.
• Follow the steps in the video below:
• If the throttle body was the issue, all should be good

The risk is if the dealer didn't properly diagnose the issue, you might still have a problem.
However, based on the code, I think your chances are good.

 

Thanks for your suggestion, I will try to get the part and get it done.
Just to make sure, the P2101 error does mean only the passenger side throttle body is a malfunction? Is there any chance both throttle bodies are down? And the part number for the passenger side is 16119-JK20D?
Thanks a lot!

 

Way too much. Definitely get a second opinion after resetting via the video posted. Definitely used over aftermarket

 

Correct. The parts diagram calls bank 1 the RIGHT BANK for some reason.
Good luck on your hunt!