A request to Vibe owners

[ke4yyd]

A couple weeks ago I made a post about "hesitation" and folks chimed in to take to the dealer. I did that today and the service writers remarks was "they all do it". So I am asking all Vibe owners that can to make a simple test and post their results.Here is what needs to be done. On level ground, drive at about 37 mph and slowly accelerate to about 40 mph. Then gently release the accelerator to maintain 40 mph. When I do this the rpm drops and after a about a second resumes back to the appropriate rpm for that speed. There is a slight jerking of the vehicle as if the engine misses or more like a starving of fuel for a second. This can also occur while driving at a steady speed between 35 to 45 mph but not as pronounced. The service writer said something about the transmission shifting and engine vacuum.Thanks

[ZubenElGenubi]

I'll give it a try. That speed range is right about where my auto shifts into O/D, so I wonder if this might be a tranny issue for you.

[engineertwin2]

If you can't hear any odd air leaks, it may not be a vacuum leak. What it sounds to me is happening is that the transmission wants to shift to O/D, does so, and realizes it doesn't have enough torque to keep going at shifts back. Also known as gear hunting...While its more common when climbing hills, it is common for transmissions to 'hunt' for gears. This shouldn't be considered outside of the standard operating conditions. Often times, there could be a shift solenoid that is slightly out of tune or perhaps sticking.I'm guessing that you are most likely driving on a road with a 40 mph speed limit and it occurs as you approach the speed limit.Another thing that could be ocurring is that you could be catching the odd position between the throttle/load sensor and actual throttle opening. If the transmission shifts, it typically does so based on fluid conditions (pressures) inside the transmission. This could cause the upshift. However, if you then still have some pedal slightly pressed (ever so slightly) the engine may sense load, and tell the computer "we're speeding up, downshift" so the transmission goes right back to the same gear it was in.That would result in an rpm drop and a jerk...

[ke4yyd]

To add to the discussion, this phenomena appears when the tranny is in Overdrive. In overdrive before and after the rpm drop. Any "hunting" for the right gear should not occur when in overdrive and decreasing the throttle position at least to my logic. I have been driving autos with EC auto transmissions for 20 years and familiar with the moving in and out of overdrive phenomena. Never had anything like this occur.

[jake75]

I never noticed anything like this. Ask the service manager to take a test drive with you in a new Vibe from their lot.

[neenahvibe]

My vibe is only 2 weeks old with 500 miles and I already noticed the very problem you describe. It's like the tranny disconnects as it's hunting for a shift. In addition I'm already having the starting problem many others speak of on this forum as well. To make things worse it also sounds like the dealers see these defects every day and are passing them off as "this is the nature of the beast, learn to live with it". This is my first "new" car and I hope it's not a nightmare. Glad there's a site like this to air our issues.

[neenahvibe]

So would you recommend that we owners with this mallady just learn to live with it?

[Katscan]

Quote, originally posted by neenahvibe »My vibe is only 2 weeks old with 500 miles and I already noticed the very problem you describe. It's like the tranny disconnects as it's hunting for a shift. In addition I'm already having the starting problem many others speak of on this forum as well. To make things worse it also sounds like the dealers see these defects every day and are passing them off as "this is the nature of the beast, learn to live with it". This is my first "new" car and I hope it's not a nightmare. Glad there's a site like this to air our issues. If it was one thing I learned from my older car that I purchased brand new. If it doesnt feel right or you arent sure about a rattle or noise or anything, take it to the dealer to get it checked out while under warrenty. If they say there is nothing wrong make sure you keep the paperwork of the visit. When I got my brand new '99 Ford Escort ZX2 the AC on the darn thing was a bit picky, I would turn it on and could feel the power drain from the engine. It was so great that sometimes while sitting at a light I would have to pump the accelerator to keep the engine from stalling. Me being dumb, I passed it off as "normal" and did nothing. 2 years later it turns out that there was a problem with my AC as it stopped working and cost me over $500 in repairs ($200 was to fix one problem only to realize there were more) Had I taken my car to the dealer while it was still under factory warrenty Im sure I wouldnt have had to fix it 2 years later after the warrenty had expired.

[northvibe]

crap i forgot to check if mine did...ill check when i go out into downtown later today.

[ZubenElGenubi]

I tried your "driving test" several times and never noticed any hesitation or sudden rpm drops or increases. Once I'm in OD, I can slowly drop the speed to as low as 33-35 mph and it will remain in OD, albeit with very low torque. Unless I punch it, it will stay in OD as I slowly increase speed.I agree with jake75, if you can regularly reproduce this problem, take a service manager along for a ride.

[nygiantzz1]

I tried to duplicate your issue with my Vibe, but have no such problem. When I ease off the accelerator and level out at 40mph, the rpm's drop to around 1400 and stay there until I accelerate again. No hesitation and no drop below 1400rpms. I have a 2006 Base with 3400miles so far. you may want to have a different Pontiac dealer look at it, or as suggested, take the Service manager for a ride and show him. Good luck with it.

[VoodooVibe]

Quote, originally posted by ke4yyd »A couple weeks ago I made a post about "hesitation" and folks chimed in to take to the dealer. I did that today and the service writers remarks was "they all do it".I have another thought regarding your problem... It may not be a tranny issue at all. I assume you have a newer Vibe with the drive-by-wire throttle system. My Vibe is an '03 and does not have that, but my brother's '05 Altima does. I notice that when I'm driving his car, at very light throttle applications (i.e. just a tiny bit of throttle), the drive-by-wire sensor in the gas pedal cannot really decide whether it's being pushed down or not. So what it does it close the throttle, then open it again, and so on. Since my brother's car is a manual, it makes for a really annoying jerking sensation.But since yours is an auto, when it's locked up in OD, and the throttle gets closed, it would immediately unlock (but remain in 4th gear) and the RPM would drop down as you describe. So when you're slowly letting up on the gas pedal to maintain your speed, it probably thinks you're getting off the gas completely for a moment, but then adds throttle again (causing your RPM to increase and the tranny to lock up).Try driving with more than just a light throttle application and see if this problem still occurs when you get to OD. Obviously when driving with more throttle you'll notice that the tranny will take longer to get into OD, but see if the RPM still drops when it gets there. My bet is it won't. It's probably just the drive-by-wire garbage

[ke4yyd]

Never heard of this drive by wife stuff but from what you describe I thing you have hit the nail on the head.

[VoodooVibe]

Quote, originally posted by ke4yyd »drive by wifelol... Basically, drive-by-wire eliminates the steel throttle cable that traditionally connected the gas pedal to the butterfly in the throttle body under the hood. Now, the gas pedal just has a sensor on it, determines what percentage of throttle you're asking for, sends that info to the computer, and then the computer actuates a small motor that opens the butterfly to the requested amount. Needlessly complicated!There may be somthing you can do about your issue. All drive-by-wire systems need to be callibrated at the factory (i.e. - they need to know when the gas pedal is fully released, and when it is fully depressed) in order to work properly. Yours might not be callibrated correctly, or the sensor on the gas pedal might be defective. You may even need a whole new gas pedal assembly...Now the real challenge is getting the dealer to concur with the diagnosis

[ke4yyd]

LOL made several spell errors. Need to use the spell checker......

[neenahvibe]

I'm beginning to think the drive-by-wire system is the culprit as well. Was driving last night in the 35-40 range and suddenly I lost RPM's (from 3k down to about 1k). Took about 5 seconds for the car to return to normal RPM for that speed. Like the original poster, I don't feel like the dealer is going to lift a finger to resolve this because it happens so rarely. I work in the electronics field and I'm guessing the electronic sensor has some latent damage. From my own experience, it's very hard to test for failures when they occur sporadically. So my question is how does one get the dealer to replace parts only on a hunch? I could bring in numerous threads from this forum but they can say "it's all just a guess, show me proof". Guess I'll just keep following different discussions on both the Matrix and Vibe and see if I can build a case over time. My warranty is up in 35K or 35 months so I have some time.

[northvibe]

yup sorry to post late i have a 2004 (no dbw) and it does NOT do that. we should ask on the matrixowners.com to see if dbw trixes are doing it to or they have a new flash on the ecu to correct that

[ke4yyd]

I can make mine do it anytime. Starting at 35 mph, slowly acelerate to 40 mph and gently lift foot off acelerator to maintain 40 mph. However, I don't have more than about 1 to 2 seconds of hesitation.It occurs at other scenarios also when driving in the 30 to 40 mph range.

[ke4yyd]

I found this discussion on the toyota nation forums which sounds similar.http://www.toyotanation.com/forum/t140502.html

[jasonvibe]

Here is the reality of DBW. The motor that moves the throttle plate is never as fast as a your foot. So there needs to be something corrected in these DBW systems. DBW was invented for cars for better gas mileage. Some motorcycles have it. But without issues. I can only say my AWD does not have it. I am glad for that. To those who have it. COMPLAIN to the "feds". Stating it is "unsafe" for a car that won't go when it needs to. And this DBW system needs to "learn" how you drive, that some people mention...is a load of BS.

[VoodooVibe]

Quote, originally posted by jasonvibe »Here is the reality of DBW. The motor that moves the throttle plate is never as fast as a your foot. So there needs to be something corrected in these DBW systems. DBW was invented for cars for better gas mileage.Well, it's not exactly like that. The motor is actually an electric solenoid, and it's very fast. But that's not where the problem lies. The problem is with the sensor in the gas pedal itself, and it's callibration.The reason people feel like they "loose RPM" (to quote the thread starter) is because under very light throttle application, the sensor on the gas pedal reports to the computer that the gas is not being pushed at all (even though it is being pushed a little bit), so the computer commands the throttle to be closed.This is apparent on almost all DBW systems. I think they need to continue development work on eliminating false readings such as this one that occur under very light throttle. Then the system would actually work well. It's possible that the sensor on the gas pedal needs to be replaced for those of you that experience this problem all the time or to a high degree of severity. If you really want it replaced, just break it yourself lolI'm sure there's a way to recallibrate it as well. Anyone with an '05 or '06 service manual can probably check that out. I know on my brother's Altima, there's a procedure to teach the computer what the gas pedal sensor will read when the throttle is at 0 (foot off) and full (foot to the floor). With that information, it can properly determine how hard you're pushing the gas. It's possible that some DBW systems may not have been callibrated correctly at the factory, or that they need to be recallibrated due to a change in the position of the sensor or normal wear and tear of the gas pedal / sensor assembly.Also, the DBW is not for fuel savings. The butterfly opens and closes the exact same way as a conventional one. So there's no difference in fuel consuption. The reason why everyone uses it now is for greater control of the engine through the ECU and cost savings. By using a DBW system, the manufacturer now does not need a separate cruise control system, a separate traction control system, or a separate idle air control system. By adding DBW, they've just eliminated the cost of three separate systems. So that's just one reason why they use it. It also allows the computer to keep the rpm up when slowing down for emissions purposes or reduce throttle application when the traction control activates on cars that are so equipped.

[scherry2]

Quote, originally posted by neenahvibe »My vibe is only 2 weeks old with 500 miles and I already noticed the very problem you describe. It's like the tranny disconnects as it's hunting for a shift. In addition I'm already having the starting problem many others speak of on this forum as well. To make things worse it also sounds like the dealers see these defects every day and are passing them off as "this is the nature of the beast, learn to live with it". This is my first "new" car and I hope it's not a nightmare. Glad there's a site like this to air our issues. does wiconsin have a lemon law? if so return to the dealer and mention the lemon law and ask for a refund or fix the car. no dealer should say "they all do that" if the dealer says it again and refuses to fix your problems mention your going to call 1-800- pontiac ( i think thats the #)and log a complaint.

[ke4yyd]

After reading the DBW reset thread I tried it on my Vibe and it cured my problems. Hard to believe the dealer service manager is unaware of this cure.http://forums.genvibe.com/zerothread?id=25238

[azsapphire87]

Sounds like this is only a problem with the new cars as they have the "drive-by-wire" electronic throttle. I've got a traditional throttle and experience no problems.Now, it's just a guess, but try to get your hands on a diagnostic scanner. It might come up with an error code that you can fix.I just got myself an Innova Equus 3110 CanOBD2 scanner. Used it just before I took my Vibe in for a smog check (renewing the registration). No problem codes. VERY useful tool.

[ke4yyd]

I have a code reader which has not indicated any problems. However, the DBW reset has solved the problem.

[joatmon]

Quote, originally posted by ke4yyd »After reading the DBW reset thread I tried it on my Vibe and it cured my problems. Hard to believe the dealer service manager is unaware of this cure.http://forums.genvibe.com/zerothread?id=25238That's great that your problem is solved. Let us know if the problem re-occurs, supposedly these ECUs are learning, and it might relearn the problem periodically. I guess I'm not all that surprised the dealer didn't know to try the DBW reset. We wouldn't have known about it if northvibe hadn't found it on the celica forum and posted it here, so to northvibe and congrats on problem solved.

[azsapphire87]

I guess I can be glad I don't have the DBW.Still glad to know you've found a solution. Goes right along with Murphy's Law: "If it can go wrong, it WILL go wrong!" Also proves that having more systems can mean more problems.

[ke4yyd]

I talked to the service writer today, who told me at the beginning of this fiasco that all Vibes did that, about the Drive BY Wire fix I performed and he said he did not know what a Drive By Wire was.

[kevera]

ke4yyd,I've noticed something similar when I,m decelerating and I apply the brake slightly around 35-40kms the transmission seems to kick down a little,it feels like a hesitation,but it's actually the transmission.It's even more noticable when travelling down a hill and applying the brakes slightly at about the same speed.I know it's not exactly as you described in your post but It has happend to me.

[noguice]

Quote, originally posted by ke4yyd »After reading the DBW reset thread I tried it on my Vibe and it cured my problems. Hard to believe the dealer service manager is unaware of this cure.http://forums.genvibe.com/zerothread?id=25238That's great that your problem is solved. Let us know if the problem re-occurs, supposedly these ECUs are learning, and it might relearn the problem periodically. I guess I'm not all that surprised the dealer didn't know to try the DBW reset. We wouldn't have known about it if northvibe hadn't found it on the celica forum and posted it here, so to northvibe and congrats on problem solved.

The thread mentioned no longer exists. Could anyone tell me what the procedure for the re-calibration is? I am experiencing very similar issues with my '05 base auto and would like to give this a try.

[Derf]

This appears to be the mentioned Drive By Wire Reset link:
viewtopic.php?f=12&t=20191

[noguice]

This appears to be the mentioned Drive By Wire Reset link:
viewtopic.php?f=12&t=20191

Thanks, I finally stumbled on this myself. Gave it a shot, It really took care of the throttle lag, but unfortunately not the problem (jerking on slow acceleration/steady low RPM throttle) I was hoping to fix.