Just did this to my 2011 with 81k miles on it yesterday following the below writeup for the G37

http://www.myg37.com/forums/d-i-y-insta ... odies.html

Same procedure. I used a microfiber rag and some throttle body cleaner from Autozone. cost me all of $5. the dealer charges $200+ for this service. My throttle bodies were gummed up bad, the entire backside and all around the butterfly valve were black and crusted.I did move the butterfly valve to clean underneath, and truthfully i think this is almost required when doing this service. i kept everything connected while working and Idle was fine afterwards.

Before cleaning i was getting major hesitation from a stop, as well as shuddering everytime i would come to a stop at a light, almost stalling the car. Now the hesitation is gone, less delay in shifts, no stalling, shuddering is gone. if your M is getting up there in miles i highly recommend doing this! All you need is a 10MM socket wrench, a 5 Hex head, and some needle nose pliers. took me about an hour, 30 mins per side in my driveway.

Thanks for posting that! Those of us who use Sea Foam in the vacuum line, crank case, and fuel tank have to remember that those procedures do NOT clean the throttle body. Personally, I was always worried about removing the TB as I have read horror stories about idle issues, etc after doing this yourself. That tutorial specifically states to NOT disconnect anything on the TB when you remove it, which I am sure I would have done so that I could take the TB to my work bench to clean it.
Very helpful info!

This may help someone that disconnects or messes up the calibration with the throttle body. They are instructions for the G35/37/Z but they may work for the M seeing as the ECU reset worked as well.

EDIT: Confirmed these instructions will work for the M... Factory Service Manual Pages EC-147 - EC-150

These instructions are from the Motordyne Plenum Spacer Installation Manual:

Important Preconditioning:

Make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.

• Battery voltage: More than 12.9 V (At idle)
  Engine coolant temperature: 70 - 105°C (158 - 221°F)
  Selector lever: P or N
  Electric load switch: OFF
  (Air conditioner, headlamp, rear window defogger)
  On vehicles equipped with daytime light systems, if the parking brake is applied before the engine is
  started the headlamp will not be illuminated.
  Steering wheel: Neutral (Straight-ahead position)
  Vehicle speed: Stopped
  Transmission: Warmed-up

You must perform all of the learning procedures in the order outlined in the instructions.



Official Instructions directly from factory service manual:

IDLE AIR VOLUME LEARNING

Idle Air Volume Learning is a function of ECM to learn the idle air volume that keeps engine idle speed within
the specific range. It must be performed under the following conditions:

• Each time electric throttle control actuator or ECM is replaced.
• Each time VVEL actuator sub assembly or VVEL control module is replaced.
• Idle speed or ignition timing is out of specification.

PRECONDITIONING

Make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.
• Battery voltage: More than 12.9 V (At idle)
• Engine coolant temperature: 70 - 105°C (158 - 221°F)
• Selector lever: P or N
• Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, if the parking brake is applied before the engine is
started the headlamp will not be illuminated.
• Steering wheel: Neutral (Straight-ahead position)
• Vehicle speed: Stopped
• Transmission: Warmed-up

ACCELERATOR PEDAL RELEASED POSITION LEARNING - First Step

Accelerator Pedal Released Position Learning is a function of ECM to learn the fully released position of the
accelerator pedal by monitoring the accelerator pedal position sensor output signal. It must be performed each
time the harness connector of the accelerator pedal position sensor or ECM is disconnected.

1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.

THROTTLE VALVE CLOSED POSITION LEARNING - Second Step

Throttle Valve Closed Position Learning is a function of ECM to learn the fully closed position of the throttle
valve by monitoring the throttle position sensor output signal. It must be performed each time harness connector
of electric throttle control actuator or ECM is disconnected or electric throttle control actuator is cleaned.

1. Start the engine. NOTE: Coolant temperature is less than 25°C (77°F) before engine starts.
2. Warm up the engine until engine coolant temperature reaches 65°C (149°F).
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Check that throttle valve moves during the above 10 seconds by confirming the operating sound.

AIR VOLUME LEARNING - Final Step

1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
4. Repeat the following procedure quickly five times within 5 seconds.
- Fully depress the accelerator pedal.
- Fully release the accelerator pedal.
5. Wait 7 seconds, fully depress the accelerator pedal for approx. 20 seconds until the MIL stops blinking
and illuminates.
6. Start engine and warm it up to normal operating temperature.
7. Let it idle for 20 seconds.
8. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the
specifications.

I got hit with a cold otherwise I would have done this today...maybe next weekend. I don't plan to remove it, I just plan to clean it with a rag and my hand/finger (lifting the butterfly valve). The outside of my TB's were generally pretty clean when I was doing the PCV replacement, but I didn't look behind the butterfly valve.

IlyaKol wrote:I got hit with a cold otherwise I would have done this today...maybe next weekend. I don't plan to remove it, I just plan to clean it with a rag and my hand/finger (lifting the butterfly valve). The outside of my TB's were generally pretty clean when I was doing the PCV replacement, but I didn't look behind the butterfly valve.

the fronts of mine were really clean too, but the back were black with the majority of the build up around the edges of the back of the valve. once you have the intake tubes off its 4 bolts. and they hang free pretty easily. just make sure you take the time to line them up when you put them back on with the O ring.

I have a 2012 M37 with 27K miles that was experiencing some hesitation on tapered acceleration.

Yesterday I followed the instructions in this thread to clean the throttle bodies. I unbolted them from the plenum, thoroughly cleaned the back side with TB cleaner and a soft rag and then re-assembled. I did NOT disconnect the electrical connectors.

The hesitation problem went away and performance seemed like new again. Today, I drove it and all was well. But, the car went into limp mode on the return trip home and throws a P1239 error code (Throttle Position Sensor).

Looking for suggestions to clear this issue.

Make sure it's all connected, obviously, and did you do all of the relearns, etc. for good measure?

Problem solved!!!

I cleared the error code and went through the calibration procedure above.

Runs like a champ...

Thank you to all who contributed to this thread.

did mine around the same mileage, probably 77k. that along with the trans reflash on my 2011 made it much more enjoyable to drive.

Just cleaned my throttle bodies and took it for a quick little drive. Very impressed with how much more responsive the car is when you touch the gas. (going to wipe ecu learned behavior at lunch)

My car has 98k on it and the TBs had never been cleaned. (had to break the factory threadlocker)

The only issue I encountered was dropping a TB bolt down in to my steering rack somewhere, but lucky the import mechanic i use is a 100yds away from my office. Got 2 spare bolts from him only to find the OE bolt when I got back.