Ive just done 30K in my MY2002 Aero, now at 118K, the only issues are that twice Ive had to have the throttle body reset and techtwoed (sounds like an owl!) to get out of limp home mode.
The first time it happened, a well regarded indy stated that the only option was to replace it at £400 - cant be reset, cant be cleaned, cant be repaired...I wasn't impressed and went away and have never gone back there.
I got it reset at another Indy who explained it may go in a mile or a year or never. It lasted about 12K and then went into limp home again. I decided to try a reset again and its been fine. So in total its cost me £40 to have two resets.
I was told first time around that the electronics had failed, well they must have repaired themselves cos theyve go on to give good service.
I accept that periodically I may pick up a limp home / CEL flag and am quite happy to pop into my new found (trusted) indy for a quick reset.
Reading around I see that the TB can be cleaned and put back into service, although as many people appear to replace them a bit like a consumeable.
My question is does anyone konow what periodically knocks the car into limp home mode? And if so is there anything you can do to mitigate that happening? I fully accept that it will have a finite life but sometimes the knee-jerk replace strategy isnt neccesary - do these things fail completely eventually or can you accept a regime of clean and reset?
Is it the electronics that go, or the butterfly valve mechanism? ECU.com will do one for £150 with a two year warranty, I'm not sure if its a superior device c.f. OEM but not too bad a deal.
p.s. I've weaned myself off Supermarket fuel (sod the nectar points) and will only buy fuel from an Oil Company (Shell etc) - would this help?
Any thoughts on what is for me anyway the only achilles heel on an otherwise excellent car appreciated.
The following information is normally relevant to earlier model year Saab 9-5 models and normally occur when fitting a new throttle body to the car.
This information may not be specifically relevant to you, but it may be worth checking that you have the latest software.
On rare occasions a new throttle body will go into limp-home mode and it is then assumed that the throttle body is faulty. Tech-II diagnostics report the following fault codes:
- P1231
- P1251
- P1260
- P1261
Saab advises that the problem is not with the new throttle body but with the vehicle. (This problem appears to be particularly prevalent on earlier model year cars, but may affect others.)
The reason is that the fault codes return and put the throttle body into limp home mode is becuase there is a software update for the engine management that is available and needs to be installed on your Saab. The Saab software update will prevent the ECU reporting erroneous problems with the new throttle body.
To resolve the problem it is the software on your car that needs to be updated. You need to speak with your Saab dealer or specialist about having the software update done. This will cure the problem that you have.
Like I say, not sure if this is entirely relevant in your case, since you appear to have an existing throttle body, but may be worth getting the software checked, if only to know that you are up to date.
Thats good info and would make sense. Previously my prefered Indy recommended a software refresh as a general good thing to do on the basis that there will be several updates from the factory that are worth having.
Ill enquire - may have it done at the same time as its upcoming service.
Cheers
There are one or two things that set the CEL off, including dirt in the TB that jams the butterfly and electronic/electrical problems.
The way the TB operates is thus:
You press the accelerator pedal and the cable runs up to the TB and rotates the first potentiometer (variable resistance).
The pedal position sensor sends a signal to the ECU which in turn makes the electric motor on the TB turn the butterfly. As the butterfly rotates, it also rotates a second potentiometer.
The two potentiometers are wired in series, such that as one increases in resistance, the other reduces in resistance. So the overall resistance should stay the same.
Obviously there will be a slight delay between you pressing the pedal and the butterfly responding. The software allows for this. The software upgrade just increased the time allowed for the butterfly to react and the overall resistance to settle down.
If the overall resistance goes out of range after the time allowed, the limp home solenoid is triggered and the pedal cable operates the butterfly directly.
The other common fault on the throttle body is for the solder joints on the edge of the circuit board, under the TB plastic cover, to crack. Re-melting them is a cure.
I started having problems with my 2003 95 Aero. It would run great for months at a time, and then fail into limp mode.
I went on line and learned how to reset it, which is really easy once you know what to do. So everytime it went into limp mode I would disconnect the battery and reset the TB, and it would be fine for months or even a year.
But then it got to the point that it was surging on the highway, and and failing all the time. It's a pain, because the idle would be so low that it stalled if I didn't keep my foot on the gas peddle to keep the RPM's up.
I ended up replacing it, the Saab parts guy sold me one at close to internet pricing, which was nice of him.
It runs great, knock on wood! I have over 265000 miles on my car, and the throttle body is the only major item I've had to replace so far.
Get it to someone who can service program the car, they will need to be a specialist or main dealer and can check to see if the software update is available. The simple course of action is that if there is an update get it done, if the car still keeps dropping into limp home after then it's probably a throttle body fault which requires a reconditioned part or a new one, or even second hand.
Have delt with this on 9.5 for last 3,000 miles. Went in and scraped the butterfly edges, cylinder walls of the TB and cleaned connecting hoses. Now, after that, can reset to clear CEL and TBS light and car runs O.K. for about 15 miles.....then the foot peddle will start feeling like the cable is binding and I can feel the friction back through the peddle.....I know when this starts that in about 3-10 miles the CEL and TBS light is going to come on...when they do, the foot peddle frees up and the car runs great on open road....only at a stop or long period of idle does it want to run rough or sometimes engine quits and have to restart and use foot peddle to increase idle. In the last 500 miles I now loose cruise control when the CEL kicks back on. Originally when the problem started I did not loose the cruise. There was quite a buildup of plac on edges of butterfly flap and after that cleaning the car really runs much better....Just cannot figure out how to handle the idle problem.