Date: 13 Apr 2007 14:46:38 -0700 From: "pzi" <pzinospamnet> Subject: Re: 9-3 viggen - Throttle Motor. Full PWM in Closing Direction
On Apr 12, 4:45 pm, Colin Stamp <col.dust...nospamp.plus.com> wrote: > On 12 Apr 2007 14:20:02 -0700, "pzi" <p...nospamnet> wrote: > > > > >On Apr 11, 4:09 pm, Dave Hinz <DaveH...nospaml.com> wrote: > >> On 11 Apr 2007 08:30:34 -0700, pzi <p...nospamnet> wrote: > > >> > I get check engine light with two fault codes: 1260 and 1251 after I > >> > took the cylinder head off to change the head gasket. > >> > The first one 1260 is the "Throttle Return Spring. Too Low Force" and > >> > the second one 1251 is "Throttle Motor. Full PWM in Closing > >> > Direction". I understand the first one but what is PWM in the > >> > second? > > >> Take a look at the spring on the left side of your throttle assembly, > >> where the cable from the pedal goes in to it. There's a spring there > >> which can be adjusted. lift up the tail on the left /bottom (little tab > >> of spring sticks out), rotate the black plastic assembly in the > >> direction that adds spring tension. Start with one notch. Not sure I > >> can describe the base setting of mine without pictures. > > >> > When this happens I feel a bit of rough operation of the accelerator > >> > pedal. I think this may be the accelerator pedal wire dirty or > >> > damaged. Strange is that this does not happen all the time - all > >> > clear for 30 min of driving and then it is. I read the codes and > >> > clear them and its ok for next 30 min. Any other ideas? > > >> I'd say that since you have the means to read and clear the codes, > >> adjust the mechanical problem that you can, and see if the other code > >> goes away. The throttle assembly isn't too much of a PITA to replace > >> but it's not cheap. The local specialist told me "sometimes resetting > >> it takes care of things" but obviously that doesn't address the root > >> cause of why it jumped a notch in the first place. > > >> Let us know what you find, please. More data we have on this beastie > >> the better. > > >> Dave Hinz > > >I took the electrical connectors apart (limp solenoid, 10pin throttle) > >sprayed with electrical cleaning spray and put them back and the ride > >to and from work went without any faults at the cpu. > >I was very gentle with the car and did not accelerate too much like I > >did the first time (full throttle to say 100mph). I will try that > >again on the weekend when I don't need the car to commute to work. > >Thank you all for comments - I feel like I am learning from you guys! > > >Also, Is there a good description of the Saab throttle body operation? > >I am kind of lost with butterflies, limp homes, etc. I am interested > >in the limp home mostly since I may have distrubed it. > > >cheers - Peter > > Well basically, it's like this... > > The cable from the pedal operates the pedal arm. This turns sensors so > the ECU knows how much power you want. The ECU then controls the > throttle motor which actually opens the throttle disk (the butterfly). > The pedal spindle and the throttle spindle should be separate from > one-another normally, so with the ignition off, you should be able to > move the pedal arm and the throttle spindle won't follow that > movement. > > In limp-home mode, the solenoid does something which locks these two > spindles together, so the throttle just follows the pedal position, > and the motor can't make any difference. > > I've just had a look in the manual, and what I didn't realize before > is that the throttle body actually latches itself into limp-home mode > when the solenoid is triggered, and it needs to be manually re-set. If > you just clear the error codes without re-setting limp-home mechanism, > "trouble codes P1263 or P1251 will be generated". > > So, it looks pretty certain that your throttle body is latched into > limp-home mode. > > Here's the procedure to reset it. > > http://www.stamp.plus.com/temp/Limp_home_reset_1.jpghttp://www.stamp.plus.com/temp/Limp_home_reset_2.jpg > > When you've finished, moving the pedal arm with the ignition off > shouldn't cause the throttle spindle to move. > > Cheers, > > Colin. Great! - I think I was missing the reset. BTW what is the manual that your pictures come from? I reqularly check google and ebay for signs of computer based manuals for saab with no luck.