Tuesday, June 10, 2008

The Saab Direct Ignition (DI) System, most models

Hello again,

Following my list of 3 common Saab failures that will leave you on the side of the road, I wanted to discuss the direct ignition system found on your Saab. If you have a 9000 turbo (91-98), NG900 turbo (94-98), 9-3 (99-02), or 9-5 (99-present), then your car incorporates the direct ignition technology developed by Saab in the late 80's.

Direct Ignition... it just sounds fancy, right?

As you know (or may not know), Saab prides itself in turbo charging. Turbochargers increase engines efficiency by forcing air into the engine, which ultimately creates more power. By doing this, it is possible to make a 4 cylinder perform at the level of many v6 and v8 engines, providing not only power, but fuel economy (everybody say yeeeah!). The advances of turbocharging, and Saabs innovation with turbochargers, outgrew the performance and ability provided by distributor style ignition systems, so Saab developed the DI system to work with its new Trionic systems. The DI also cleans the plugs after you shut the car off. It runs through a 5 second burn off cycling, in which time it ignites all the plugs with very hot spark to clean the ignition surfaces of the plug!.

A Direct Ignition cassette, this one is red which indicates that this is a T5 system

What the DI system does is eliminate all of the common ignition components found on conventional ignition systems for a more... turbo friendly? ignition system. The ignition system is managed by Saabs Trionic software, which comes in two (technically 3) versions, Trionic 5 and Trionic 7. The MY93 9000's had a special version of T5 different from all others (94-98).

Also, for owners of 2003+ 9-3's, your Saab has a coil pack ignition system, which has 1 individual coil pack per cylinder and is operated by Saabs Trionic 8 system. I have yet to deal with this system enough to comment on any failure trends.

The DI system is housed within the DI cassette which sits on top of your engines spark plugs and ignites them with an electrical charge generated within the cassette. It is essentially a computer. It also can read knock and spark temperature through the spark plug itself, a capability distributor style ignition systems would never be able to incorporate.

Here we see the inner workings of a T5 DI cassette

Now, why is all of this important to you? These DI's commonly fail, and the vehicle will cease to operate immediately upon failure. The most common failure pattern I tend to see with them is an overheating of the small pocket of oil inside of the DI, which will then spill out into the circuitry. I'm not sure which comes first in this case, the chicken or the egg, but either it overheats and spills, frying the circuits, or spills from the circuits overheating.

What causes this?

No really, I'm asking you.

What I'm saying is that there is not really a common point at which these DI's fail. I've heard tell of a friend of mine putting on a brand new one from Saab, and it failing a week later. My 1994 9000 Aero made it 200k miles on its original DI cassette, yet some only go 60k. The DI is not a service item, and is never replaced by Saab unless it fails. I personally keep a spare on hand at all times in my trunk, because you really are at the mercy of it when you're driving.

A T7 Black DI, you can also see the boots which sit on the spark plugs

Replacing a DI is simple and only takes a matter of minutes, failures can often be identified by the smell that a DI puts off after failing, one of a burnt electronic nature. The lesson here is check your DI, there is a date code stamped on the label underneath. It will read something like 0250. The first two digits indicate the year, and the last two indicate the week. 0250 would mean a DI made in 2002 on the 50th week. Remember though, this does not indicate when the DI was installed, just when it was produced. If you have an older DI, I would suggest purchasing a spare to keep, just in case.

I keep both T7 and T5 used DI's on hand, price for T5 used DI's is $150 and $125 for T7 DI's. The two must not be interchanged, as they are meant to work specifically with the T5 or T7 system. As I already mentioned, T5 DI's are red and T7 are black. If any of you Saab-o-philes feel otherwise about DI interchangeability, this is not the place to discuss it.

However, this is. =)

There is also a recall on T7 DI cassettes, I will check your car for this during service to see if it has been done.

Anywho, I'll be doing some less common jobs over the next few days (vent flap motor on a 87 9000 Turbo with Automatic Climate Control, a transmission flush and filter replacement on a c900 automatic, and a Manifold Absolute Pressure sensor on a 9-5), I will post about all of that by the end of the week when they are completed.

Take care until next time,
-Chad

37 comments:

Sebastian said...

Hi, your blog is really interesting. Thanks!
Since you are an expert on Saabs I have a question: I have a '99 Saab 9-3 2.0L Turbo. Earlier this month the coil pack broke down, so it was replaced but the car started shaking while driving so the coil pack was replaced again.
Today while driving the car lost all power and according to the mechanic the coil pack is broken again.
What would cause a coil pack to break down again in these cirumstances? Putting on another coil pack does not seem like the solution and the problem might occur again. Is there some electrical configuration which needs to be set when installing a new coil pack?

Many thanks and best of luck with your cycling.

klbar2008 said...
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John said...

Hi, John here. My wife has a 9-3 convertible 1999. Check engine light is on all the time. ran a dignostic and it has something to do with the ignition. Could the Ignition Cassette be the cause of the check engine light? Thanks for you time

klbar2008 said...
This comment has been removed by the author.
Jordan said...

hello jordan here..i have a 2001 saab 93 and my car seems to not wanna start after its at a normal operating temp.It'll start no problem when cold..Could there be short circuit in the direct ingnition. A friend said that could b a FI problem..Just had air fuel and oil filter replaced..any help is appreciated!the mechanic cant figure it out either
thanks jordan

klbar2008 said...
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Patrick said...

Will just one out of four coils in the cassette fail to make the car run on three cylinders?

klbar2008 said...
This comment has been removed by the author.
Jose said...

Hi! I have a 2001 93 se turbo and I have a problem with the accelerator, every time I let off the gas it makes a gurgling or butterfly sound can someone help. Thanks!!

Jose said...
This comment has been removed by the author.
http://www.youtube.com/klbar2005 said...
This comment has been removed by the author.
vif said...

Good Morning,
I have been trying to find some information about Saabs failing to start after coffee spilling into ignition. My wife avoided hitting a deer by stopping abruptly but had her coffee spill. We hoped the ignition would dry out and allow the car to start, but that hasn't happened. Have you run across this problem before?
Thank you
Reed@veryimportantfish.com

http://www.youtube.com/klbar2005 said...
This comment has been removed by the author.
Auto said...

As for Saab, the Swedish car from General Motors, servicing is essential especially because Saabs are known to be pricey and therefore more attention has to be given and retained.

Saab Service Adelaide

klbar2008 said...
This comment has been removed by the author.
Auto said...

Saab is the exclusive automobile royal warrant holder as appointed by the King of Sweden. It was originally a division, established in 1944, of the Swedish Aeroplan company.

saab service

cars admire said...
This comment has been removed by the author.
kilimanjaropics said...

Hi
I am a serious SAAB lover. I have a 1990 SAAB 900s that I have had for years, but recently started developing a lot of problems. The most recent is after starting and getting warm the engine will stall and will not start for a few minutes. This happens while it is standing or driving. It just knocks out. To date I replaced the fuel filter, new spark plugs and a set of wires, checked the Throttle Position Sensor. New coil wires. New Alternator. Nothing has worked and I am hemorrhaging money trying to find a local mechanic who can honestly work on it and identify the problem. I did replace the fuel pump about less than a year ago, but now I wondering if the mechanics really did replace it because he said he replaced the fuel filter and it turned out to be the same old filter when I had it changed recently. It's hard to find an honest mechanic in this troubled economy where I live. Your thoughts would be appreciated.

Thanks
David

Yess! said...

I have a 2004 9-5 Saab arc. We think its the DIC. occassionaly when we stop the car seems to shudder. we got the error code for the crank position sensor and for misfires. we replaced the position sensor but the engine light is still on. We're trying to check all other alternatives so what are the chances I just need to replace the spark plugs?

Boompa said...

Old and blog-challenged,so bear with me.
Just bought a 2002 9-3 from an out-of-town used car dealer through auction. Said service was due in December at about the current mileage.
On the drive home, the check engine light came on - on a Sunday.
After freaking out, found a Auto Zone and they ran the diagnostic.
Codes came up as misfiring 4th cylinder. I haven't pulled the plugs yet to check, but would this indicate a problem with the DI?
Thanks!

d.b. said...

does anyone know where I can purchase a crankshaft position sensor for a 1990 SAAB (standard shift) 900s? Seems the company that made this item stopped. Thansk?

Chad Lowers said...

@boompa: Yes, definitely DI.

Blairware said...

Simply SAAB is a bit TOO simple for my taste. Why put a SAAB Blog out there, tell everyone your expertise, and then leave every single inquiry unaswered (except for some bizarre answers from KLBAR from Egypt. Wasted time, waste of a read. The info on the DIC wast technically correct, but extremely basic. It's blogs and websites like this that turn people OFF to getting help on the internet. I won't otther with the question I have since the op wrote this in 09, or earlier, and never responded to anyone who asked questions. It's not even a very entertaining discussion, just a lot of sad stories from SAAB owners.

klbar2008 said...

Blairware
thanks alot for yours kind comment!!
now no more bizarre answers from KLBAR from Egypt. or Wasted time, and wasted read !!!!!!!!!!!!!!

Chad Lowers said...

I apologize if anyone feels like this is a wasted resource. It is a free source of information on the technical functionality of an advanced automotive electronic system, that is all. If you have questions and would like them to be answered in a forum style atmosphere, I suggest www.saabnet.com. I run the shop singlehandedly and work 60hrs a week doing so, so I rarely even notice there is a comment on here. Apologies for that, but paying customers in the shop are always priority.

cars admire said...

thanks alot Chad Lowers for your's
kind comment and i really would like to have a job with you in some
day!

Michael said...

Chad,

Your blog just saved me from wasting $550 on a DI recommendation from my dealer. Keep up the good work!

Blairware, where is your Saab blog or valuable contributions? Or do you like to just air your superiority over all things?

- Michael

Giggles said...

guys i hope this helps you guys out a little im no car pro but spent a ton of time trying to figure this out for myself . If you get a code of P0340 or P340 this would indicate that your CAMSHAFT sensor is bad not CRANKSHAFT sensor,but here's the kick. Many saabs including mines 1999 9-3 DO not have a CAMSHAFT sensor they are built in the DIC. So to make it easy the easiest thing to do is change your spark plugs and make sure they are resistor plugs and if that cheap fix doesn't work unfortunately your DIC is going bad and you will need to purchase a replacement. Hope this helps most of you guys.

love lost said...

dscrine tecuthGreat blog. I failed inspection for codes p1312 and p1334 but have no check engine light. Any ideas?

JD2145 said...

Hey, I've got a 98 saab 900se. While idle it wants to and sometimes does stall, like at traffic lights. I'm waiting in a pcv to come in which could b the problem but I'm wounding if this is common and possibly something else, something pricey. Please get back to me with what you know.
Thanks, Jon

Unknown said...

JD2145, I've had a similar problem with my 1999 9-3 SE. It did prove to be the direct ignition cassette which had an intermittent.

Patrick said...


Thank you for your clear explanation.
Maybe you know whether it is possible that the Di occasional piece (short circuit) and the fuse 26 engine management destroy?

patrick greetings from the Netherlands




Jeffrey Hering said...

Thanks for explaining the DI component. I have a 1996 900se convertible, 2.0. Love it and it looks brand new. I am looking to replace the DI system because I had the same problem with the engine acting very sluggish. I pulled the DI off and noticed a crack. So time to replace it, got 90K from it! My question is, should I replace the spark plugs at the same time?

gwsevt said...

@Jeffrey Hering I know it's a late response for you but maybe others will have the same question...so, yes absolutely you should always replace the plugs when replacing the DIC. Speaking from personal experience and research. Thank you @Chad Lowers for this. It is a very thorough, clear and informative explanation of the system what it does and why. Even after knowing much of the info (having replaced a unit or two) I learned quite a bit and it has demystified some of it for me. I for one like knowing the reason for things, helps me "get it". Anyone who wants more can go look for it and anyone who feels it's "too simple" can choose not to read it. The beauty of these blogs, forums and the internet search feature! :)

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Howard Blum said...

I get "brake, ABS, TCS OFF lights lit every 30 mins for a few mins and when I stop the engine rumbles. Could this be the DIC?

George Taylor-Tomic said...

I personally would pay for your consultation. If I had a particular issue with the SAAB I would ask for your opinion, and pay for that service. If you have a PayPal account I would pay directly into that. I'm sure I would save a lot of time and money dealing with you. Regards