So the other week we had a Mercedes C 230 Kompressor come in that wouldn’t start. The key wouldn’t turn in the ignition but when you inserted the key, it acted like you had turned the key. We connected the Mercedes Star Tester and we had an ignition switch code for KL15 constantly on.
Mercedes ignition switches commonly have a problem similar to this caused by excessive heat and cold and the main microchip on the circuit board of the ignition switch can fail. Now, you can take your Mercedes to the dealership and let them rake you over the coals, because the myth is, if it has to do with the security of the vehicle, up to an including a simple key, you need to take it to the dealer. We don’t like to follow the rules as far as overpaying for a repair so we went to work, figuring a way around this little problem.
Our customer was a huge help and provided us with a resource that we definitely will be using in the future. With the sincerely appreciated help of Murphy at Euroluxury Auto, in Ontario Canada, we were able to diagnose and discover the problems. Whenever you have two separate problems at the same time in the same subsystem, the diagnosis difficulty factor increases exponentially. Here, we had the chip problem on the ignition switch shown here and we also had an additional problem.
While we were diagnosing the ignition switch we disconnected it. Upon doing this, the ignition (KL15) power stayed on. NO MATTER WHAT we did. Even if we disconnected the battery, and reconnected it, the ignition stayed on. The lights stayed on and the steering wheel was always unlocked, even with the battery disconnected(this was a blessing because we were still able to push the car around).
After discussing the problems with Murphy at EuroLuxury, we determined that the module in the power distribution block, under the hood on the drivers side contains a module with a circuit board and integrated circuits. Upon disassembling the module (and removing the rats nest of wiring(this thing has 20 plug connections)) we found corrosion on the circuit board. Murphy said he has one on hand and is shipping one tomorrow so hopefully we’ll get this puppy running and a smile back on our customer’s face. I’ll keep you posted as this is a developing story.
We received the SAM midule(as its called) and after plugging in the polethera of connections, we are happy to report that the vehicle now starts and runs as it should. Now as this vehicle was sitting for some time and picked up at discounted sitting prices, it still needs a bit more work to be roadworthy but not to worry, because driving this puppy around all fixed up at thousands, if not tens of thousands less than a brand new car, the owner will be able to save for the house he wants to buy. He understands that repairing the vehicle you already own is the most economical choice a vehicle owner can make.
See you on the road my friends,