Limp Home Mode - most likely causes

[philmeup007]

OK, I need some help diagnoising a problem. Overview: 1999, 9-5 Wagon, V6, 293,000 miles. I was accelerating to about 45 mph, when I heard what sounded like air escaping a tire for about 3 seconds. I assumed I had hit something and was losing a tire. Within about 10 more seconds I could feel the car slowing. Within about 3/4 of a mile, I was able to get it into a parking lot instead of being stuck by the road side. As I coasted to a stop, the engine died. It's now in Limp Home mode but will only stay running for about 3 seconds and then shuts down. I can't afford our local SAAB dealership so I have it with a mechanic "new" to Saabs (family friend). In the past I've had at DI Cassette go and the Traction Control module that resulted in the Limp Home Mode occuring. Where should we start?

[raquettelaker2]

Check all the intake tubes/hoses/boots for tears or leaks. I think it's not all that uncommon for the intake tube closest to the driver side front headlamp to actually tear underneath. Let us know what you find out!

[zachc]

yah check all yr IC hoses too. i blew one n my car threw itself into LHM.

[philmeup007]

Sorry for being a newbie. I've done my own brakes, waterpump, belts, and oil on the car for years, but what and where are the "IC" hoses?

[raquettelaker2]

Originally Posted by philmeup007

Sorry for being a newbie. I've done my own brakes, waterpump, belts, and oil on the car for years, but what and where are the "IC" hoses?

IC = Inter-cooler.

It's sandwiched in with the radiator. Follow the intake tube from the throttle body down to the bottom of the car and you'll find where it connects to the inter-cooler. There will be another hose on the other side of the car too that comes from the turbo.

[philmeup007]

May I also ask: If and when we find a leak in one of these hoses, what do I need to do to get it OUT of the Limp Mode?

[zachc]

reset the TB.

very easy. 5 min job.

go here....


http://photo.platonoff.com/Auto/2004...home_reset.jpg


oh. and clear your codes if any.

[philmeup007]

Since we don't have a computer to reset the codes, I assume that I can pull Fuse #17 (as discussed in other posts) for 5 mins?

[philmeup007]

New Information: When they pulled off the trailer this AM, he started is and said it ran; but ran rough! Weird, it wouldn't run for me. Also yesterday I pulled fuse #17 (for 5mins) to clear the codes and read in another post that once this is done it needs to run for 5 mins to "relearn" the driving modes. What does that mean?

Also, my guy DOES have a computer. These are the codes he got Multiple Misfire P0300 and Low Boost P1300. Also, pulled the front DI Cassette to look at the plugs and said that the Valve Cover gaskets were leaking so bad there was 2 inches of engine oil around the plugs, he was surprised it was even running. His suggestions were: Plenum Gasket, Valve Cover Gaskets, new Spark Plugs and Spark Plug wires. Then we will take it from there. Are we headed in the right direction? Is the Low Boost code mean that my Turbo is dead?

[Chris 9-5]

Originally Posted by philmeup007

Also, my guy DOES have a computer. These are the codes he got Multiple Misfire P0300 and Low Boost P1300. Also, pulled the front DI Cassette to look at the plugs and said that the Valve Cover gaskets were leaking so bad there was 2 inches of engine oil around the plugs, he was surprised it was even running. His suggestions were: Plenum Gasket, Valve Cover Gaskets, new Spark Plugs and Spark Plug wires. Then we will take it from there. Are we headed in the right direction? Is the Low Boost code mean that my Turbo is dead?

Does he have any Saab knowledge though?

You dont have spark plug wires for example..........

The DI cassette (or both) and old plugs could well be a source of the multiple missfires, but you will need to sort that oil leak out first probably.

I wouldn't worry about the turbo just yet lets get the "spark" right first

[Chris 9-5]

Ok lets talk ECU resets and Fuse 17.......

Our cars have a very clever engine management system, it constantly adapts to optimise efficiency, sometimes this will be at the cost of out right performance, say for example in heavy traffic........

But not all adaptation is bad, the ECU usually adapts to enhance the engine management to the conditions it is sensing.

To force the ECU to lose this "learnt" information you can pull fuse 17 or disconnect the batter but I'd say for at least 20 mins.

Now the ECU is fresh and ready to adapt again, you can go and drive it hard and then some people report the car feels initailly much livlier, of course it will adapt continually back to where it was.

Pulling the fuse or disconnecting the battery will also enable you to lose some fault codes causing a Check engine light, if the light comes back on, clearly the fault still exists - we wouldnt recommend simply pulling the fuse, but getting the fault code read first if you get a check engine light.

[philmeup007]

Yeah, sorry, no Saab knowledge, so I am kind of helping him along. He's good, just never worked on a Saab. Thanks for answering the questions tho.

In solving the oil leaking by replacing the Valve Cover gaskets, what other gaskets will we need? My guy mentioned a "plenum" gasket, but in my parts search on www.thesaabsite.com, I'm not sure I am finding right gasket.