Last post on Oct 25, 2013 at 5:57 AM
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Pontiac Bonneville, Transmission, Sedan
#59 of 80 Confusing 2000 Pontiac Bonneville SE
Jul 07, 2010 (6:27 pm)
Hello, I am looking for some advice. I have had my Bonne for a year & a half and my tranny seems to get worse the longer I have it. I have done the fluid & filter change regularly. As of late my throttle position sensor has been acting up. I replaced it with a new one from the dealer & it seemed to help my tranny shift better. But now my car is idling high and my check engine light goes on and off by itself. This high idling problems has been prominent for the past 3-4 months. Sometimes I have to start my car a few times before I can pull off to reset the computer (I guess?) and my car typically will drive fine for awhile. I have noticed when I run shirt errands that it runs smoothly.
Is there any correlation between the throttle position sensor and transmission?
How likely is the problem my computer?
Could it just be my tranny?
------------I have replaced the shift solenoid and PCS------------------
#60 of 80 Re: Confusing 2000 Pontiac Bonneville SE [phoenix86]
Jul 08, 2010 (4:15 am)
Sounds to me you might have a vacuum leak. I believe those will sometimes set a code or light. But I think the code I heard didn't obviously appear to come from a vacuum leak, but when analyzed it made sense. This is why it's important to troubleshoot anything before replacing parts. The box parts stores have started shying away from just letting people buy parts after running the code checks on the cars for them. I've heard counter guys helping people analyze the meaning.
Check all around the perimeter of the upper intake manifold. Check all rubber hoses and connectors for cracks, softness, hardening, especially on sides toward hot motor where they might deteriorate and not be visible. The vacuum leaks can cause a high idle. With the upper intake, as it warms, it expands and may be sealing a leak or crack.
You can use a carburetor spray around the areas where leaks might be with the motor idling. If there's a leak the extra hydrocarbons sucked in causes a change in idle speed and sound.
#61 of 80 2003 bonneville tranny
Jul 23, 2010 (5:34 pm)
Need help I have 2003 Bonneville when I"m driving it comes in out of gear sometimes you just let off the gas and it goes back into gear other times u have to put her into netural then drive and she goes find this happening like every so often is the tranny shot?
#62 of 80 Re: 2003 bonneville tranny [cverbosky]
Jul 23, 2010 (5:44 pm)
How many miles and what kind of service in the way of trans fluid drains and filter changed?
Whst does the color of the transmission fluid on the trans dipstick look like?
I would say I've changed my 2003 leSabre at 35K and 70K. I put in Dexron VI which is a synthetic blend that replaces the original fluid Dexron IIIe (I think that's right, check the back of the glovebox manual). That means with a drain and fill that only about 50% of the fluid is replaced. That's good. New additive cleaners to pick up stuff collecting in places where it's affecting the operation but not a totally new 100% shock of lots of additives. I do not believe in the flushes that shops like to do.
#63 of 80 99 Bonneville shifting hard
Aug 31, 2010 (6:51 am)
My 99 bonneville runs great normally but at low speeds when the transmission shifts in and out of 1st/2nd/3rd gear multiple times in short succession (i.e. rush hour traffic) bad things happen. The transmission will shift hard and acceleration is hesitant or non-uniform in the higher gear. Once I let off the gas completely and ease on the petal the acceleration is OK (till the next shift). Basically I pretend like its a manual and try to time up letting off the gas at the shifts (15mph and 25mph). Then after my car sits overnight the problem goes away.
My mechanic replaced the ECU, ICM, manually checked the voltage levels (he had it for 2-3 weeks), and flushed the transmission fluid. After this did not fix the problem he told me that the transmission would likely need to be rebuilt eventually. After researching the issue I want to replace the crankshaft position sensor in any attempt to avoid rebuilding the tranny. Any knowledge you can share would be an enormous help as I am pretty much on my own to solve the problem.
#64 of 80 Re: 99 Bonneville shifting hard [ryankoglin]
Aug 31, 2010 (7:19 am)
When were your spark plugs and wires changed? How many miles are on the car now?
Because it seems to struggle after shifting, I'd suspect them first.
Or, check each of the coils for corrosion in the sparkplug towers and on the prongs that insert into them underneath. Check the resistance on each and make a list. You can take the coils off one at a time easily. Sometimes coils give trouble when hot only. That's difficult to test for.
You "mechanic" replaced the ICM, or I would have you check the connector on the end of it.
When the car is doing this, stop. Turn the car off. Restart. See if it continues. I believe there was a problem with a computer control item that would reset.
I would also take off and clean my MAF sensor without touching the two wires inside. Use a cleaner for MAF from auto store. I did use a camel hair artist brush when the wires were wet.
After car has given the problem. Stop. Take off the engine cover and pull the vacuum hose off the FPR. See if liquid fuel comes out of the hose or if you get a strong gas smell out of the hose. The fuel pressure regulators sometimes leak extra fuel.
Beyond that, you might have a fuel pump pressure problem. Sometimes pumps lose pressure when the pump gets warm after use and the fuel warms after being out in the hot ambient temps. If it doesn't do this driving when it's cooler, I'd take loan of a fuel pressure gauge with a long enough hose I can tape it to the outside of the windshield with duct tape and drive. See your typical pressures and see if there's a change when you car acts up.
Beyond this I think you're at the wrong shop. The shop didn't diagnose. He hung new parts. Expensive.
I think you need an up-to-date transmission shop that can watch the pressure control module and the various solenoids in the transmission during the shifts while driving it. A dealership who does transmissions would do this with their Tech II, I believe. A quality transmission shop also will have the same or better capability.
Crankshaft position sensor?
How many miles?
Has it ever stalled for you? And then restarted easily or required a period of cooloff to restart?
I think you would have mentioned a stall problem and you didn't. I would put CPS lower on the list.
The EGR valve migh be acting up or sticking open slightly. It can be removed and checked. I believe it should have set a code for you and set the check engine light if it was not working properly.
#65 of 80 trans interchange
Sep 05, 2010 (2:11 pm)
will a 95 & 97 pontiac bonneville transmission interchange
#66 of 80 94 bonnieville
Dec 14, 2010 (7:36 am)
#67 of 80 Torque converter and solenoid replaced but engine light come on
Dec 16, 2010 (7:34 pm)
I just got my 99 Bonneville back from the shop yesterday. I took it in after a series of issues that started with a violent jerking after low speed coasting and stepping back on the throttle. It did this twice in a row, so I dropped it off at a local shop and they didn't come up with any fault codes. I drove it on home and used the car for another month, but noticed a few peculiar shifts especially after coasting out of a corner and stepping back on the gas.
Monday I went to town in it and the Check Engine light came on, and it started shifting hard and a couple of time it just didn't seem to want to go after shifting. I dropped it back off at the shop and this time they informed me it was a torque converter and solenoid fault code which made since to me because of the way it was acting. They replaced these parts.
I got the car back yesterday and all seemed well for the first 12 miles and the Check Engine light came back on, but it runs and shifting perfect. I took it straight back and they plugged it in and the transmission guy said it was the same code as before. He said he thought it hadn't had the computer reset.
Does that make sense?
He reset it and also said, "drive it and if the light comes back on it might be the throttle sensing..." or something like that. My wife took it to town today and after about 90 mile (we live way out) the light came back on again.
It runs, shifts, and drives perfect, and just had a tune up about 200 miles ago.
Does it make sense that out of the blue there is now a throttle sensor issue, or did they put in faulty parts?
#68 of 80 Re: Confusing 2000 Pontiac Bonneville SE [imidazol97]
Apr 10, 2011 (3:05 pm)
the high idling could be just the out side air temp. i live in North Dakota and when i start my car in the morning it will idle at around 1500 RPMs. you can drop the idle by taping the gas to snap it out of the warm up idle. it would do this when it is 30 degrees or colder it seems with my car at least.