Anyone else have this problem on a '03 TL Type S. With car in gear and sitting at a stop, car will jerk forward when the AC system kicks in under the hood. Jerks with enough force to make the car move forward with foot on brake. Kind of feels like someone accidently nudging your bumper from behind. Seems more pronounced the longer the car has been driving.

 

I have the same but not with such force...
Not sure if its normal

 

Force will only make it move slightly forward. Sometimes you can feel it but it doesn't have enough force to make it move. Seems to happen any time I hear the AC system (fan maybe) kick in under the hood. Have you ever taken it in to have it looked at?

 

I've heard its a common problem ... I have it too and its quite pronounced. I'll probably get it looked at when they replace the timeing belt (coming up soon). Don't want them messing around if it ain't broken.

 

Yes, since day one. Compressor kicks-in and the cars lurches (brake pedal sinks a bit). I've attributed this to the fact that the brake booster works on engine vacuum; when the compressor kicks-in the vacuum drops as the RPM's drop momentarily causing a pressure difference in the booster. I could be wrong though...

 

Yeah... but I'm wondering if through wear and a faulty timeing belt tensioner (see TSB) that some of us are feeling this more pronouced lurch. I'm probably being way too anal.

 

its normal... but then again acura says that about everything of thier cars... even their F'd up tranny's...

 

Yea man, my 03-S has the same problem, since i got it from the dealer

 

This is a common complaint with the 2nd gen TLs. Definitely noticeable at a stop with your foot on the brake. But it is normal.

 

Any chance you were driving a manual before? I came from a manual, where you seldom have to use the brakes at a stop unless on a hill. I noticed it a ton. After a while, you don't notice it as much.

 

I get this in my 02 TL Type-S, and also from my 93 Camry LE V6. I always assumed it's normal when the AC kicks on.

-Victor

 

yep! happens to me too!! dont be surprised!

 

You're almost right.

When the compressor engages the engine's rpm will drop from the extra load on it. When this happens it is then raised due to an actuator being tripped when the A/C comes on. The actuator gives a signal to the Idle Speed Control Servo. This is to compensate for the loss in RPM's (and thusly horse power) because the A/C take "that" much power to use. It's just that the computer isn't programmed as specific as it could be to match the engine's "at idle" rpm (obviously it's a little over).

The brake pedal sinking is from the extra vaccum that the engine is producing now that it's at a higher rpm. More vaccum = more braking power.

Try driving a four cyl. car with an auto trans and have that sensor NOT work. You could puch the car faster than it will go by itself.

 

funny thing- at also happens on honda accords. THAT FACT pisses me off.. this is a friggin acura, small things like that should be corrected. On all accords (ex-v6) the trannies kick when coming to a full stop, acuras have corrected that. they should've fixed the a/c thing too.

i wonder if 04s do that.

 

funny thing- at also happens on honda accords. THAT FACT pisses me off.. this is a friggin acura, small things like that should be corrected. On all accords (ex-v6) the trannies kick when coming to a full stop, acuras have corrected that. they should've fixed the a/c thing too.

i wonder if 04s do that.

 

Wow what a relief knowing I'm not the only one this is happening too thought I was nuts looking for the phantom driver hitting me from behind .

 

Anyone been able to find a fix for this issue?

 

when this happens to me i usually look in my rear view cause i always think i got bumped from behind

 

Put more pressure on the brake peddle.

After I cleaned my throttle body, air manifold and reset the ECU the surging has seemed to go away.

 

Anyone besides the last poster find a fix for this issue?

 

there isnt a fix. Its just not using enough brake pressure. when the AC compressor kicks in the ecu throws a little more rpm to compensate, hence the surge. If you think you have something more than normal bring it to the dealer. It may be a trans/tq converter issue or a broken motor mount.

 

YEA, brake harder and it wont lunge forward.

 

Happens to me ocationally. I figured it was a load factor.

 

Same issue with my 03 Tl-p

 

Ohhhh! So that's whats causing that. I noticed it a day or so after I got my car. I checked my rearview to see if someone hit me! I never associated it with the A/C though.

Cool, I'm glad that's "normal."

 

I'm guessing that with the car in drive, and the rise in RPM from the computer compensating for load, it's as if you were to blip the throttle. The pressure you put on the pedal to stop an idling car is obviously less that what you would put to slow a car moving even 5 MPH. I get it when the cooling fans come on, but I've gotten so accustomed to it that the moment I see/hear/feel a drop in RPM I immediately push a little harder on the brake. Usually stops the car from looking like I'm a RWD starting a burnout, .

~Cheers~