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Discussion Starter #1 (Edited)
Hi there, I've done a couple of searches but I'm really stuck as to what's making my lovely Saab 9-5 2-0t Automatic (2004) stall when brakes are applied.

My first notion was that the Cranckshaft Position Sensor was screwed (again), but the symptoms are different this time around.

The symptoms:
- Shifter is in "Park"; engine will not start unless I apply a little gas.
- Engine runs fine when started, but as soon as I apply the brakes the engines rpm drops until it stalls.

While looking around in the engine bay I notice that:
If I disconnect the vacuum line the engine runs fine, I can apply brakes and the engine does not stall. As so as I connect the vacuum lines the engine stall (if it's in idle and brake is applied). I've supplied a couple of pictures to show which vacuum line I disconnected.

Any suggestions as to what could be the main issue would be greatly appreciated!!!

KS
 

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Hi there, I've done a couple of searches but I'm really stuck as to what's making my lovely Saab 9-5 2-0t Automatic (2004) stall when brakes are applied.

My first notion was that the Cranckshaft Position Sensor was screwed (again), but the symptoms are different this time around.

The symptoms:
- Shifter is in "Park"; engine will not start unless I apply a little gas.
- Engine runs fine when started, but as soon as I apply the brakes the engines rpm drops until it stalls.

While looking around in the engine bay I notice that:
If I disconnect the vacuum line the engine runs fine, I can apply brakes and the engine does not stall. As so as I connect the vacuum lines the engine stall (if it's in idle and brake is applied). I've supplied a couple of pictures to show which vacuum line I disconnected.

Any suggestions as to what could be the main issue would be greatly appreciated!!!

KS
Sounds like you might ave a faulty check valve, replace it and see if it runs better
 

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Discussion Starter #3 (Edited)
Sounds like you might ave a faulty check valve, replace it and see if it runs better
I've just been down at the local dealer to ask about the Check Valve, according to him there is no such thing as a "Check valve" on a Saab 9-5 2.0t 2004 Automatic, He meant I should get a tube with a couple of "bells" on it, i dont have a part number for it, but basically Im replacing the tube and bell attached in my first post.

Sorry for my apparent ignorance on the matter.

Thanks for your reply.
 

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I've just been down at the local dealer to ask about the Check Valve, according to him there is no such thing as a "Check valve" on a Saab 9-5 2.0t 2004 Automatic, He meant I should get a tube with a couple of "bells" on it, i dont have a part number for it, but basically Im replacing the tube and bell attached in my first post.

Sorry for my apparent ignorance on the matter.

Thanks for your reply.

Those "bells" are check valves ... replace that, it is a good start.

You also could have a leak in your brake booster ... not nearly as much fun as the part you are looking at replacing. :roll:
 

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Discussion Starter #5
Those "bells" are check valves ... replace that, it is a good start.

You also could have a leak in your brake booster ... not nearly as much fun as the part you are looking at replacing. :roll:
Excellent! I guess I need to keep my fingers crossed!

Thanks for your insights!

I'll report back when the fix (hopefully) is complete.
 

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Discussion Starter #6
Just replaced the check valve, and the problem persists :cry:

SaabScott initially suggested that it could also be the brake booster. I've purchased a error code reader and the output of this reader is:

P1230 - Throttle position (TP) sensor 1 & 2 - range/ performance problem
P0102 - Mass or volume Air Flow Circuit Low Input


Anyone?
 

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Discussion Starter #7 (Edited)
This is getting stranger and stranger by the minute. After posting the last entry I erased the error codes, turned the ignition and the engine started

First at 4000 rpm then all the way to 1000 on idle (looked to me as if my Saab was trying to find the correct idle speed). All well so far.

Then I went for the mandatory test run, after the first full throttle attempt the check engine light was lit, but it would still idle but on a very low speed, maybe 500 rpm. When I got home I did a new scan with my newly aquired toy and read out:

P1251
- control module low output

Do I have an electrical or a mechanical (or both) problem?
 

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Discussion Starter #8
An update, it turns out that the mechanical limb mode was tripped.

Following this excellent guide on resetting this mechanical limb

http://www.youtube.com/watch?gl=HK&hl=zh-HK&v=nlqyT9eNMuU

and resetting the error codes makes my car as new, that is, until I go for "full" acceleration, then the error codes show up again (and a clicking sound on the left hand side), leading me to think that perhaps it's the throttle body that's the issue?

Error codes this time around was
P1251 - control module low output
P1260 - Saab Throttle Return Spring Too Low Force
http://saabworld.net/f144/p1260-throttle-return-spring-25087/

Any Suggestions would be greatly appreciated.
 

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Discussion Starter #9
An update, it turns out that the mechanical limb mode was tripped.

Following this excellent guide on resetting this mechanical limb

http://www.youtube.com/watch?gl=HK&hl=zh-HK&v=nlqyT9eNMuU

and resetting the error codes makes my car as new, that is, until I go for "full" acceleration, then the error codes show up again (and a clicking sound on the left hand side), leading me to think that perhaps it's the throttle body that's the issue?

Error codes this time around was:
P1251 - control module low output
P1260 - Saab Throttle Return Spring Too Low Force
http://saabworld.net/f144/p1260-throttle-return-spring-25087/

Any Suggestions would be greatly appreciated.
 

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Discussion Starter #10
An update, it turns out that the mechanical limb mode was tripped.

Following this excellent guide on resetting this mechanical limb

http://www.youtube.com/watch?gl=HK&hl=zh-HK&v=nlqyT9eNMuU

and resetting the error codes makes my car as new, that is, until I go for "full" acceleration, then the error codes show up again (and a clicking sound on the left hand side), leading me to think that perhaps it's the throttle body that's the issue?

Error codes this time around was
P1251 - control module low output
P1260 - Saab Throttle Return Spring Too Low Force
http://saabworld.net/f144/p1260-throttle-return-spring-25087/

Any Suggestions would be greatly appreciated.
 

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Discussion Starter #11
Update

An update, it turns out that the mechanical limb mode was tripped.

Following this excellent guide on resetting this mechanical limb

http://www.youtube.com/watch?gl=HK&hl=zh-HK&v=nlqyT9eNMuU

and resetting the error codes makes my car as new, that is, until I go for "full" acceleration, then the error codes show up again (and a clicking sound on the left hand side), leading me to think that perhaps it's the throttle body that's the issue?

Error codes this time around was
P1251 - control module low output
P1260 - Saab Throttle Return Spring Too Low Force
http://saabworld.net/f144/p1260-throttle-return-spring-25087/

Any Suggestions would be greatly appreciated.
 

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Discussion Starter #12
An update, it turns out that the mechanical limb mode was tripped.

Following this excellent guide on resetting this mechanical limb

http://www.youtube.com/watch?gl=HK&hl=zh-HK&v=nlqyT9eNMuU

and resetting the error codes makes my car as new, that is, until I go for "full" acceleration, then the error codes show up again (and a clicking sound on the left hand side), leading me to think that perhaps it's the throttle body that's the issue?

Error codes this time around was
P1251 - control module low output
P1260 - Saab Throttle Return Spring Too Low Force


http://saabworld.net/f144/p1260-throttle-return-spring-25087/

Any Suggestions would be greatly appreciated.
 

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Discussion Starter #13
I was unable to post yesterday (maybe I had to many posts in a row?!?)

Anyway, to recap what happened yesterday:

..resetting the error codes makes my car as new, that is, until I go for "full" acceleration, then the error codes show up again (and a clicking sound on the left hand side), leading me to think that perhaps it's the throttle body that's the issue?

Error codes this time around was
P1251 - control module low output
P1260 - Saab Throttle Return Spring Too Low Force

I removed the throttle body for a deep clean, and wouldn't you know, all my error messages are gone!

Thanks for all suggestions!
 
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