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Lou P. master tech
Lou P. master tech, Mercedes Technician
Category: Mercedes
Satisfied Customers: 3726
Experience:  15 years master certified 100% fix rate and have access to factory radio codes, wiring, and instructions.
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Instrument cluster/dash lights flashes ON and OFF smart key

Customer Question

Instrument cluster/dash lights flashes ON and OFF smart key won't turn in the ignition switch
JA: Is the car in "Park" or "Neutral?" Do you know if your car has a "wheel lock" feature?
Customer: Wheel lock?
JA: Tell me a bit more about what's going on so he can help you best.
Customer: Vehicle doesn't start
JA: Are you hoping to fix this yourself?
Customer: I intend to.
JA: Is there anything else the Mercedes Mechanic should be aware of about your Mercedes?
Customer: What happened to the long narrative I wrote?
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Mercedes Mechanic about your situation and then connect you two.
Submitted: 5 months ago.
Category: Mercedes
Expert:  Kevin replied 5 months ago.

Hi I'm Kevin all the symptoms you describe suggest that the battery is low I would recommend charging or replacing battery before going any further

Customer: replied 5 months ago.
I have already done that still didn't work.
Customer: replied 5 months ago.
Is there any fuses block or fusible link that I have missed?
Expert:  Kevin replied 5 months ago.

I don't have this info on your model il opt out another tech will have this

Expert:  Lou P. master tech replied 5 months ago.

Hello, i can assist, first off and most importantly what year and model are you working with and do you have more than one ignition key?

Customer: replied 5 months ago.
No, only one key 2002 S430 the one with the push start button on the shifter but not working.
Expert:  Lou P. master tech replied 5 months ago.

ok there was a issue with the old dash clusters that would have an internal short, they were a huge issue back in the day, BUT they would not inhibit starting, so let me ask a few other questions,

  1. do the locks work with the key fob
  2. can are any exterior lights on with the headlight switch in the OFF position
  3. does the radio and exterior lights turn on if you turn them on?
Customer: replied 5 months ago.
1 Fob don't lock or unlock the doors
2 No
3 Radio doesn't come on, exterior light do come on with switch but blinks like Dash lights
Expert:  Lou P. master tech replied 5 months ago.

Ok, sorry for my delay I got pulled away. There is a voltage issue in the car. Do you have a test light AND a multimeter ?

Things we need to check

  • Is battery installed correctly and the voltage 12.0 or above
  • You have 3 fuse boxes. Left and right of engine bay and under back seat on passenger side behind panel by the feet , use a test light and make sure power is present at all fused and document the fuse numbers that do not have power. We may have a blown PREFUSE that will kill power to the fuse boxes. So we are not simply looking for a blown fuse. Bonus if we find any but we are concerned with the fuse boxes having power.
  • When you verify power at fuse boxes with a test light then use the meter on one fuse and see if the voltage matches the battery voltage.

These tests will tell us what may be happening. Let me know what you find and we can proceed. Lou P.

Customer: replied 5 months ago.
PREFUSE? CAN YOU PLEASE MAPOUT THE LOCATIONS OF THESE PREFUSES. YOU'RE 100% CORRECT ABOUT SOMETHING IS CUTTING MY POWER SUPPLIES BECAUSE WHENEVER I DISCONNECT THE BATTERY CABLE AND REATTACH IT THE AIR SUSPENSION COMPRESSOR COMES ON FOR EXACTLY A MINUTE THEN IT SHUTS OF AND NEVER TO COME ,UNTIL I REPEAT SAID PROCESS.
Customer: replied 5 months ago.
Hello
Expert:  Lou P. master tech replied 5 months ago.

Hello so sorry for the delay, i had my little sisters wedding out if town since last thursday , i really apologize, are you still wanting my help?

Customer: replied 5 months ago.
Customer: replied 5 months ago.
Please read my previous thread.
Expert:  Lou P. master tech replied 5 months ago.

i did, and again my apologies.

Expert:  Lou P. master tech replied 5 months ago.

the info you provided just tells me there may be a fault with the air ride system. i still need you to check for power at all the fuses with the key on to see if we have power everywhere , those are easier then accessing the prefuse boxes

Customer: replied 5 months ago.
The key doesn't work at all Lou.
Customer: replied 5 months ago.
The only thing that works on this vehicle is the valet key.
Expert:  Lou P. master tech replied 5 months ago.

sorry, i forgot that part but this is still an important test as fuse get power from straight battery as well, so if there is a fuse that is missing power that should have power then we trace that to the source, even though the key does not turn i still need to know this info.

Customer: replied 5 months ago.
The smart key looks like my ex-wife beautiful and virtually useless to me.
Expert:  Lou P. master tech replied 5 months ago.

............i cannot laugh as my wife will wonder why..... do not get me in trouble tonight :)

Customer: replied 5 months ago.
The Two front SAMS has power, I haven't checked the rear SAM yet .
Expert:  Lou P. master tech replied 5 months ago.

ok, it is very important though to know what fuses specifically do not have power if you find any. you must use a test light on each one, please keep that in mind.

Customer: replied 5 months ago.
I Will have to tackle that task tomorrow Lou ,please don't disappear on me,the vehicle is in a Shop I manage. And by the way you can have my ex-wife I hope you have a lot of money because she's going to dismantle it for you. I'll keep in touch.
Expert:  Lou P. master tech replied 5 months ago.

omg lol, lets focus on the car lol, i will not disappear on you , if i have to leave for an extended time i will surely notify you and get you to another expert.

Customer: replied 5 months ago.
Hey Lou ,are you there?
Customer: replied 5 months ago.
Rear Sam all the fuses has power except for the LIGHT GREEN FUSE 5AMPS NO POWER.
Expert:  Lou P. master tech replied 5 months ago.

here

Expert:  Lou P. master tech replied 5 months ago.

did you also verify that all the fuses have 12.3 or so volts as the same as the battery? how did you test the fuses just so we are on the same page.

Customer: replied 5 months ago.
Right SAM
Orange 5 amps fuse 2.0 volts
Purple 15 amps fuse 2.0volts
Black pair fuse 15 and 40 fuse both battery voltage
Grey four in role 5amps 2.0 volts,10amps 0.1 volts,7.5amps 0.1volts and 15amps 0.1volts.
And these other fuses are not color coded
15amps battery volts, 20amps fuses both has 2.0 volts 40amps three in role, middle two has 0.0 which are ground I believe. The last 40amps has battery volts.
Customer: replied 5 months ago.
sir ,I did.
Customer: replied 5 months ago.
Hey Lou, I have verified that all SAMS has power from battery and all fuses are powered.
Expert:  Lou P. master tech replied 5 months ago.

ok then we need a scan tool so check fault codes, it needs to be a mercedes star diagnostic machine. we must have a communication systems fault then, the only thing i can think of without codes is to check the rear fuse box connections, remove the rear fuse box and unplug the connectors and check for corrosion.

Customer: replied 5 months ago.
The rear Sam ?
Customer: replied 5 months ago.
Is there a way for the star DAS TO WORK ON THIS VEHICLE WITHOUT THE IGNITION BEING IN THE ON POSITION, ?KEEP IN MIND THAT THE KEY DOESN'T WORK
Customer: replied 5 months ago.
Drive side Sam was replaced with same part number and same year model.
Expert:  Lou P. master tech replied 5 months ago.

not drivers side sam, rear sam that is attached to the rear fuse block, and the star diag should still connect with the sam and eis modules with the ignition off.

Expert:  Lou P. master tech replied 5 months ago.

ok so just to confirm,. you do have the battery installed correctly as far as positive and negative cables are concerned? and also the cables are tight so you cannot twist them correct?

can you tell me if this issue happened all of a sudden or what?

this is taking too long, we should have found something by now. something is not adding up.

Customer: replied 5 months ago.
I was about to set the damn thing ,but the damn vehicle is so damn beautiful, plus I live in Texas I wouldn't know what law I would be breaking.
Expert:  Lou P. master tech replied 5 months ago.

lol, dont do that haha

Customer: replied 5 months ago.
On fire, I meant
Expert:  Lou P. master tech replied 5 months ago.

oh i know what you meant

Expert:  Lou P. master tech replied 5 months ago.

so when did this start? what happened to the car right before this started?

Customer: replied 5 months ago.
I really don't know, but I think the battery ran down and since then I have replaced with new one and yet no luck.
Customer: replied 5 months ago.
The PREFUSES YOU were talking about,where are their location ?
Customer: replied 5 months ago.
There is a little junction box on passenger side floor board with something like a giant fuse on it. Please give me some info on this.
Expert:  Lou P. master tech replied 5 months ago.

that is the prefuse box to the front sams, if you have power at the fuses like i asked you then all the prefuses are ok. what is the current voltage at the battery?

Customer: replied 5 months ago.
12.4v
Expert:  Lou P. master tech replied 5 months ago.

ok, now check from the positive terminal to the body sheet metal.

Customer: replied 5 months ago.
Samr
Customer: replied 5 months ago.
Same voltage
Customer: replied 5 months ago.
But one thing I have notice is, when I turn on the headlights, the driver side lights blink on and off and does the rear taillights.passenger side works normal.
Customer: replied 5 months ago.
Buddy where are you?
Expert:  Lou P. master tech replied 5 months ago.

Sorry I have the kids from 3:30 until bed time. Did you try to read any codes in the eis module or Sam modules?