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Weirdness after ECU reset?

Old Apr 21, 2011 | 12:30 PM
  #1  
MUMM RA's Avatar
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Weirdness after ECU reset?

After all these years of wanting...no longing for a G, I finally picked one up back in Febuary. It's an '05 6mt. Fresh!

I did an ECU reset by removing the battery cable(-) for about 12 hrs and things were running smooth. I didn't even really notice a change. Well today I noticed that when I accelerate and giving it anything more than half throttle, the rpm's go up then drop about a few hundred then climb again. WTF? For an example: Let's say the car in front of you slows down and turns. You slow down a bit but not enough to downshift and then give it gas to accelerate. This is when I notice it. It's kinda hard to explain.

Any idea whats wrong? Thanks guys!
 
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Old Apr 21, 2011 | 03:27 PM
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your clutch is slipping.
 
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Old Apr 21, 2011 | 09:48 PM
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Being a 6mt I don't think it's a clutch slip. Try this... all of it. It takes some practice but does work.

ECU Resetting Procedures

This link was provided earlier for a Basic ECU Reset, but in case it's ever broken I thought a hard copy on site might be appropriate. Perhaps even a spot on the FAQ board?

http://www.technosquareinc.com/350reset.htm

NOTE: Please read all instructions and be familiar with them before any attempts. Timing is extremely critical. If it is NOT DONE within the specified time, the ECU will not reset and the Check Engine Light (CEL) will continue to remain ON. There is NO margin of error. A stop watch or an analog clock with a second’s hand is mandatory.

<u>Basic ECU Reset</u>

Operations Procedures:

1. Confirm that accelerator pedal is fully released, turn ignition switch “ON” (NOT start) and wait 3 seconds.
2. Repeat the following steps (2a and 2b) procedures quickly five times within 5 seconds.
2a. Fully depress the accelerator pedal (HARD).
2b. Fully release the accelerator pedal.
3. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 10 seconds until the CEL starts blinking.
4. Fully release the accelerator pedal (while the CEL is still blinking)
5. Wait about 10 seconds.
6. Fully depress the accelerator pedal and keep it for more than 10 seconds.
7. Fully release the accelerator pedal (The CEL light will continue to blink).
8. Turn ignition switch to “OFF” position and now you can start the car. The CEL light should be gone. If the CEL light continues to remain ON, repeat the above steps. Remember, timing is EXTREMELY critical to resetting the ECU. You may even need someone's help to do this correctly.


Note: The following reset procedures are directly from the 2004 G35 Sedan Service Manual.

<u>Accelerator Pedal Released Position Learning</u>

Description:
Accelerator Pedal Released Position Learning is an operation 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 harness connector of accelerator pedal position sensor or ECM is disconnected.

Operation Procedure:
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.


<u>Throttle Valve Closed Position Learning</u>

Description:
Throttle Valve Closed Position Learning is an operation 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.

Operation Procedure:
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.


<u>Idle Air Volume Learning</u>

Description:
Idle Air Volume Learning is an operation to learn the idle air volume that keeps each engine within the specific range. It must be performed each time electric throttle control actuator or ECM is replaced, or if idle speed or ignition timing is out of specification.

Preparation:
Before performing Idle Air Volume Learning, 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 12.9V (At idle)
- Engine coolant temperature: 70 - 100 Degrees C (158 – 212 Degrees F)
- PNP switch: ON (Park/Neutral Position Safety Switch - AT only, MT fully depress clutch)
- Electric load switch: OFF (Air conditioner, rear window defogger, headlamps. Note: on vehicles equipped with daytime light systems, if the parking brake is applied before the engine is started, the headlamps will not be illuminated.)
- Steering wheel: Neutral (Straight-ahead position)
- Vehicle speed: Stopped
- Transmission: Warmed-up (For A/T models, drive vehicle for 10 minutes.)

Operation Procedure:
1. Perform "Accelerator Pedal Released Position Learning"
2. Perform "Throttle Valve Closed Position Learning"
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
7. Repeat the following procedure quickly five times within 5 seconds:
7a. Fully depress the accelerator pedal.
7b. Fully release the accelerator pedal.
8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stops blinking and turned ON.
9. Fully release the accelerator pedal within 3 seconds after the MIL turned ON.
10. Start engine and let it idle.
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the specifications:

Idle speed A/T: 650rpm, + or - 50 rpm (in P or N position)
Idle speed M/T: 650rpm, + or - 50 rpm (in N position)
Ignition timing A/T: 15 Degrees BTDC, + or – 5 Degrees BTDC (in P or N position)
Ignition timing M/T: 15 Degrees BTDC, + or – 5 Degrees BTDC (in N position)

13. If idle speed and ignition timing are not within the specification, Idle Air Volume Learning will not be carried out successfully. If idle speed and ignition timing are within the specification and Idle Air Volume Learning cannot be performed successfully, find the cause of the incident by referring to the following Diagnostic Procedure:

1. Check that throttle valve is fully closed.
2. Check PCV valve operation.
3. Check that downstream of throttle valve is free from air leakage.
4. When the above three items check out OK, engine component parts and their installation condition are questionable.
5. If any of the following conditions occur after the engine has started, eliminate the cause of the incident and perform Idle Air Volume Learning all over again:

- Engine stalls.
- Erroneous idle.
 
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Old Apr 21, 2011 | 10:29 PM
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I'm a 6mt too and my clutch went out a while back... I bet it's a slipping clutch.
 
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Old Apr 22, 2011 | 12:45 AM
  #5  
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Yeah... I've only experienced that on a loaner auto g. I do agree it's likely a slipping clutch issue if when the rpm's go up the car doesn't accelerate, and the problem is happening all the time and very repeatable. This can also happen more random like if the throttle body has been messed with, then the procedure above fixed it.

If you do go for a new clutch check out ACT or JWT. The OEM clutch isn't so great.
 
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Old Apr 22, 2011 | 09:05 AM
  #6  
MUMM RA's Avatar
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Sorry for the bad vid, but this is in third. How much longer do you guys think I have on this clutch? Its gonna take awhile to save up a grand or more!

http://www.youtube.com/watch?v=pBnShPMKUro&feature=youtube_gdata_player
 
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Old Apr 22, 2011 | 11:35 AM
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From: Boulder, CO
Good call lil beezy!

Yeah, slipping clutch for sure. Time is hard to tell because it depends how much you drive, how easy you drive it, etc.. you basically need to get it fixed asap. It's not safe to ignore it. Not cheap for sure but critical.
 
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Old Apr 22, 2011 | 08:10 PM
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Same thing started happening to me this past week. I modded my pop charger and noticed it more and more. I was thinking I had to retune my car. Are you guys sure it's the clutch slipping? there's no smell or anything. My mileage is near OP's too.
 
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