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Weird throttle problem.

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Old 11-09-2012, 05:09 PM
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N80
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Default Weird throttle problem.

I just replaced my battery yesterday and now the throttle in my 07 Enthusiast is acting weird. It only happens at low speed, like in a parking lot. Right when I start to depress the gas pedal it is like an on/off switch rather than linear. I have always found the gas pedal on this car and my wife's 07 G35x to be way to sensitive but this is much worse.

At low speeds I have to be extremely careful or it surges forward. I feel like I'm learning how to drive a manual all over again. Once I get going there is no problem and shifting up through the gears seems normal.

The thing that concerns me is that I'm out of town for a track weekend right now. I don't think it is going to be an issue as long as nothing else happens or gets worse.

Any ideas what is going on? Did I change something when I changed batteries? Would an ECU reset help?
Old 11-09-2012, 07:24 PM
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binder
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throttle body relearn. Search it on here or on google. There is quite a list of things to do but it's not real hard.
Old 11-10-2012, 03:36 PM
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N80
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I think you're right. No problems on track today so I'm not going to mess with it tomorrow either. The procedure looks like a pita....there should be a button.
Old 11-12-2012, 10:04 AM
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N80
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I did the first steps (2sec on 10 sec off, etc) no help. Looks like I'm going to have to do the whole elaborate procedure. Kind of ticks me off that it is this difficult to get the car to function properly just because the battery was disconnected.

At the track it was no big deal. Driving in a parking lot is pretty close to dangerous. It will chirp the tires unexpectedly.

Curious if one of the various OBD plug in devices can be used to reset this?
Old 11-12-2012, 11:43 AM
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I feel your pain; I'm having the same problem as you. I removed the neg terminal cable to the battery to install an aftermarket hub/QR and ever since the throttles been messed up. I've tried the throttle body relearn process a few times, but none of it has given me any results and the problem still persists. At the moment, i have the neg cable removed again and letting it sit for a few hours and going to reconnect and hopefully it resets the ecu and *crosses fingers* the problems are gone?

As OP said, is there any way to plug in a device to fix this?

Anyone have other possible solutions to the issue?

I'll be following this thread
Old 11-12-2012, 11:57 AM
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N80
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I wonder how much the dealership charges to do this? It would tick me off to no end to have to pay to get it done but the reset process looks difficult to execute correctly.

Quite frankly, I'm surprised that this is not a liability issue. The car is very difficult to drive slowly and is very unpredictable.
Old 11-12-2012, 03:59 PM
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Just as an update, I left my neg terminal cable unplugged for close to 5 hours and i just reconnected it now and let the car warm up for about 5 minutes to operational temperature. Took it for a test run and it seems as if the "surging" of the throttle has cleared itself (gone away). I'll update again if anything comes up, but it seems good right now after a 5 mile test low at low speed (15-25), mid (30-45), and freeway speeds (60-90); no more extra sensitive throttle response.
Old 11-13-2012, 05:30 AM
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binder
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Originally Posted by N80
I did the first steps (2sec on 10 sec off, etc) no help. Looks like I'm going to have to do the whole elaborate procedure. Kind of ticks me off that it is this difficult to get the car to function properly just because the battery was disconnected.

At the track it was no big deal. Driving in a parking lot is pretty close to dangerous. It will chirp the tires unexpectedly.

Curious if one of the various OBD plug in devices can be used to reset this?

Make sure you meet all the requirements in the FSM. If you are missing 1 thing the procedure will look like it works but there will be no change. There is a list of about 10 things that must be "true" before it will work properly and hold the new changes. I know a lot of people don't have the car to proper operating temp and the other major one is having a check engine light. Either of those will not allow it to reset. When I get home I'll screen cap the picture out of the manual unless you can just download it. I don't have the manual on my laptop (although I thought I did).
Old 11-14-2012, 05:59 AM
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Jeff, I would appreciate that. I don't have the FSM for this car....got one for my 06 G35 6MT but it might not have the same codes/procedures. I think I can download the FSM for my Z somewhere but have not searched for it yet.

Stitch, what is the verdict? Did the unplug work? I took the neg terminal off mine this moring and will hook it back up this afternoon. Hope it works. So busy right now don't have time to do the reset procedures.....especially since it will invariably take multiple tries to get it right.

So I'm driving my 03 F150 SuperCrew for now.
Old 11-14-2012, 06:20 AM
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Crap, I got home late last night and forgot. The 06 reset procedure is the same as the 03. I downloaded the 03 manual from a link I found on this site. Again, if I don't forget I'll try to get a screen cap of that page in the manual when I get home.
Old 11-14-2012, 10:40 PM
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As far I know, I haven't had a problem with the throttle ever since i replugged the neg cable back in. Did it work for you OP?
Old 11-15-2012, 04:08 AM
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No. Left it unplugged for 8 hours. No change at all.
Old 11-15-2012, 09:05 AM
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Idle Air Volume Learning

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 under any of the following conditions:


Each time electric throttle control actuator or ECM is replaced.
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 12.9 V (At idle)
Engine coolant temperature: 70 - 100 °C (158 - 212 °F)
Park/neutral position (PNP) switch: ON
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
For A/T models with CONSULT-III
Drive vehicle until "ATF TEMP SE 1" in "DATA MONITOR" mode of "A/T" system indicates less than 0.9 V .
For A/T models without CONSULT-III and M/T models
Drive vehicle for 10 minutes .

OPERATION PROCEDURE

Without CONSULT-III

NOTE:
It is better to count the time accurately with a clock.

It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit has a malfunction.
Perform EC-77, "Accelerator Pedal Released Position Learning". See: Powertrain Management\Computers and Control Systems\Accelerator Pedal Position Sensor\Testing and Inspection
Perform EC-77, "Throttle Valve Closed Position Learning". See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Programming and Relearning\Throttle Valve Closed Position Learning
Start engine and warm it up to normal operating temperature.
Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.
Turn ignition switch OFF and wait at least 10 seconds .
Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds .
Repeat the following procedure quickly five times within 5 seconds .
Fully depress the accelerator pedal.
Fully release the accelerator pedal.
Wait 7 seconds , fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stops blinking and turned ON.
Fully release the accelerator pedal within 3 seconds after the MIL turned ON.
Start engine and let it idle.

Wait 20 seconds .

Rev up the engine two or three times and make sure that idle speed and ignition timing are within the specifications.
If idle speed and ignition timing are not within the specification, Idle Air Volume Learning will not be carried out successfully. In this case, find the cause of the incident by referring to the DIAGNOSTIC PROCEDURE.

DIAGNOSTIC PROCEDURE

If Idle Air Volume Learning cannot be performed successfully, proceed as follows:


Check that throttle valve is fully closed.
Check PCV valve operation.
Check that downstream of throttle valve is free from air leakage.
When the above three items check out OK, engine component parts and their installation condition are questionable. Check and eliminate the cause of the incident. It is useful to perform EC-132, "TROUBLE DIAGNOSIS - SPECIFICATION VALUE". See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Monitors, Trips, Drive Cycles and Readiness Codes\Specification (SP) Value
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.

Last edited by Neimad; 11-15-2012 at 09:12 AM.
Old 11-15-2012, 09:07 AM
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EC-77 Accelerator Pedal Released Position Learning

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


Make sure that accelerator pedal is fully released.
Turn ignition switch ON and wait at least 2 seconds .
Turn ignition switch OFF and wait at least 10 seconds .
Turn ignition switch ON and wait at least 2 seconds .
Turn ignition switch OFF and wait at least 10 seconds .
Old 11-15-2012, 09:08 AM
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Throttle Valve Closed Position Learning

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


Make sure that accelerator pedal is fully released.
Turn ignition switch ON.
Turn ignition switch OFF and wait at least 10 seconds . Make sure that throttle valve moves during above 10 seconds by confirming the operating sou
Old 11-15-2012, 09:09 AM
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Silly FSM, do the prep steps, then do the last two posts, then the rest. I just copied and pasted it, sorry for the mess.
Old 11-15-2012, 10:04 AM
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N80
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Thanks man. I sure hope this works.
Old 11-15-2012, 12:41 PM
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there ya go. so a lot of little things need to be correct before it will work.
Old 11-15-2012, 01:00 PM
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N80
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I'm going to give it a shot tomorrow afternoon.

[rant ] I am amazed that this happens just as a result of loss of battery power. Really unbelievable. But it is even more shocking that is the process the service technicians have to use! How can there not be a way to access the ECU via computer and reset things that way?[/rant ]

[semi-related rant] I assume most of this is a product of 'fly-by-wire' throttle control. To be honest, I have always hated 'fly-by-wire' throttles. I've never driven a modern vehicle that gives as good a throttle feel as a regular 'analog' throttle (throttle cable control). But, I've never owned a Porsche or a BMW either so that might be why.[/semi-realted rant]

Anyway, thanks again and wish me luck.
Old 11-27-2012, 02:42 PM
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Tried it again. All conditions met. Timed with the aid of an assistant. No help. In fact, the MIL (CEL) would never flash at all.

The problem is driving me crazy.

Dropped by dealership and talked to guy at service desk. Showed him the procedure in the FSM. He said the ECU would have 'learned' all this on its own after a fairly small amount of miles. He had no idea what the problem was....but I don't think he was a technician or the service manager. About all he would commit to was that I needed to make an appointment.

Doubt I'll get out of there for under $100...... if I'm lucky. I'm beginning to have doubts that they'll be able to fix it. I'm very, very frustrated. This should not happen simply from disconnecting the battery.


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