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Discussion Starter · #1 ·
I had my car drop in to limp home mode this morning. Stopped at traffic lights and the car stalled, started OK but revs will drop off completely and stall if I let them, CEL and TCS both lit up. The CPS and DI are both only about 18-24 months old so it is unlikely that it is them and the car has been running perfectly up until this. I did almost run out of petrol yesterday and would have only gone about 2 miles since refilling so could it be some [expletive deleted] from the bottom of the tank that has caused it?

Using my son's car now so not running the Saab. Not sure when I can get to Saab to get checked out with a tech2 so had hoped to do a bit of diagnostics myself first - any suggestions?

Martin
 

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The only DIY I can suggest is that you clean the throttle body. If the butterfly in that, which is electrically driven, does not follow the expected opening given by the throttle pedal position, you will get a limp home. Usual reason for not following is crud in the body.
 

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Discussion Starter · #3 ·
The only DIY I can suggest is that you clean the throttle body. If the butterfly in that, which is electrically driven, does not follow the expected opening given by the throttle pedal position, you will get a limp home. Usual reason for not following is crud in the body.[/b]
Any guides available on how to do this - mechanic skills are limited but willing to give it a go especially as I have a few days off next week
 

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My car went into limp mode, then stalled when it nearly ran of petrol mounting Shap on the M6. I stopped on the hard shoulder waited 10 mins, then it restarted and stayed in limp mode, I drove it the 1.5 miles to the nearest service station, filled up, on re-starting again car became normal, never happened again. Personally I think the ECU thought there was no fuel in the car (SID was reading 0 miles, despite it reading 21 miles before the incident happened!!!!)

Mr Perceptive
 

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The ECU wouldn't have shut the engine down due to lack of fuel, the pump runs regardless.

As for cleaning the throttle body, you'd need to take of the intake pipe to it, open the flap using your fingers and wipe around the area, if the body is in limp home, you will need to reset the body and error codes, which can only be done by a TECH II AFAIK.
 

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The following link will guide you to information as to resetting the limp home on the throttle body

Reset Limp Home


To reset the CEL and clear all codes remove Fuse 17 (ECU) from the fuse panel adjacent to driver's door. After 5 minutes reinsert. If CEL comes on again and throttle body goes back into limp home mode then you have a problem that will need a SAAB technician and a TECHII to resolve (probably). If the CEL remains out and the throttle body does not go back into limp home mode then you had a temporary glitch.

One drawback is that removing fuse 17 also clears the ECU of all adaptation settings and the car will have to learn your driving modes again - not really a problem - do a search on the forum for the quick method of resetting adaptation. Some will say you need to leave fuse 17 out for a long time but this is not necessary - 5 minutes is enough and I speak from personal experience.
 

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Discussion Starter · #7 ·
OK, so I have to remove the plastic cover around the oil filler cap to gain access and remove the intake pipe to check out/clean the throttle body - somebody suggested carb cleaner, do I spay that inside or what? Is there anything else I need to remove before I am able to reset the unit?
 

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Discussion Starter · #8 ·
Thanks for the info - code was not a great help as was very general, the garage said it could have been muck in the fuel line. Limp home now reset and all seems to be ok. Only time will tell.
 
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