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Saab Electrical Problems

208 Views 7 Replies 6 Participants Last post by  Mimmi
Good morning, fellow Saab drivers,

Could you help me or think along with me regarding the following problem?

I own a Saab 9-3 Sport-Estate, 2006 model, Diesel, with 150hp. It's a Swedish car.

Sometimes, I am unable to start the car. I receive messages on my screen indicating that the traction control is not functioning and there is a stabilizer warning. I have to turn the key multiple times before the car starts, and it only starts when the warning messages do not appear.

After a while, I noticed that the check engine light does not illuminate when I turn the key to the "on" position. When the check engine light does not come on, I am unable to communicate with the engine control unit (ECU), and this seems to be the reason for the warning messages.

Since then, I have learned that I don't need to turn the key all the way to determine if the car will start or not. Instead, I just need to turn the key to the "on" position multiple times until the check engine light comes on, and then the car will start.

I have watched several YouTube videos where people remove fuses, but those methods did not work for me.

I have also observed that the car starts more quickly when the weather is cold or when the car has not been driven for several hours. This leads me to conclude that temperature has an effect on whether the ECU powers on or not, though I'm uncertain why.

I have tried to locate the ground cable of the ECU, but I have been unable to find it. In most YouTube videos, the ECU was easily visible when they opened the hood, but mine is located in front of the right wheel, almost at ground level.

At this point, I am at a loss as to where to look for a solution. My last option is to take it to a garage, but I'm concerned about potentially incurring significant expenses as they investigate the problem.

To sum it up:

  1. The car doesn't start when the check engine light does not come on (possibly indicating the ECU not waking up or functioning).
  2. When the check engine light does illuminate, the car starts and operates normally.
  3. Temperature appears to have an influence.
I should also mention that the car was not used during the winter in Sweden and got buried under 1.5 meters of snow. I'm worried that moisture or the cold might have affected the ECU, considering its close proximity to the ground.

Furthermore, someone else replaced the battery, and I am unsure what type of battery was installed previously. Currently, I have an Exide Premium 85AH 12V 800A(EN) battery in the car, but I'm unsure if this is the correct type.
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1 - 8 of 8 Posts
You need to scan the car for codes, preferably with a Tech2 scanner.
It could be your ECU, but it seems just as likely that it could be your ignition switch. Hopefully a scan will reveal something useful.
You need to scan the car for codes, preferably with a Tech2 scanner.
There are no codes stored. But i only scanned with a regular obd2
I'd check carefully ECU and ECU wiring looms.
I once had this happen on a different NG9-3.

Disconnecting the battery for 1 minute made all the problems go away.

I did pull out every fuse and relay in the underhood electrical centre and clean up or replace any corrosion on the contacts.
It does sound like a wiring or ECU issue. You are correct about not seeing the CEL = no comm with engine computer. The colder temperatures could be allow the wiring or solder points within the ECU to make enough of a contact for communication to occur.

It's best to take a look at the wiring diagram.

On another note, checkout this youtube series. It may help you troubleshoot the issue as it sounds somewhat similar.
OP has DIESEL, which ECU is located WORST POSSIBLE PLACE and dirt/clay/sand/water mixture will make a hole in ECU and mixture will destroy PCB permanently.
ECU wiring looms are idiotic placed, they run 180 degree right from ECU.
1 - 8 of 8 Posts