Odd problem

[bembo449]

This has got me stumped , the 215 indicator flashes rapid inside the car but not outside when you turn left , diagnosed as a dodgy bulb holder as the use of the drivers side bulb holder cured it , got another bulb holder but the problem persists, no idea how thats possible

 

[LostKiwi]

If the drivers side bulb holder fixed it (which is known to be good) then if the fault reappears with 'new' one suggests the new one isn't that good?
What happens with the new (or old) one in the drivers side?

 

[bembo449]

You would think LK , i thought the same soooo i moved the drivers side one again but it still does , ive never known a car flash fast inside but not outside anyway , the new bulb holder works fine in the drivers side too

 

[bembo449]

Does the rapid flashing mean the earth to the bulb is poor or ??

 

[Oldspanners]

Does the rapid flashing mean the earth to the bulb is poor or ??

Measure the resistance to earth through the bulb and holder on both sides to compare.
Looks like there is enough current to light the bulb but not enough to persuade the control that there is a functioning bulb.

 

[bembo449]

I would like to avoid replacing the whole unit if poss pal , will do as you suggest and report back
Thanks

 

[bembo449]

Ive checked as instructed i get 1.2 on each holder with a bulb inserted, bulb are both the same too, only thing i can see is one holder is a 3 PBT the other is 4 PBT , both are PY21W thow

 

[bembo449]

My auto sparky says flasher unit or BSi whatever that is ?? Anyone know where either are on a 215 ,can they be checked using scan tool ??

 

[bembo449]

Plugged in MB2, got codes for both frm SAM units relating to indicators, deleted both codes , they dont return but the fault remains

 

[Wighty]

Is the flasher unit some sort of relay that is listed on the fuse charts?

 

[Martian]

Bembo,

A strange problem indeed - especially so as I do enjoy troubleshooting these 'esoterical' electrical issues - probably due to the fact that my background is with electronics!

As I have yet to venture into Mercedes ownership, (actively looking for a reasonable E Class), I am still very 'wet behind the ears' with regards to the various models but the electrics will be the same throughout the various model range!

If the problem still exists then please provide a little more detail and I am sure it can be sorted with minimal fuss, (famous last words), and if it were not for the current situation I would be more than pleased to meet up with my test gear as I believe we are both located in the same county!

I have had a bizzare problem with my SLK, (long since gone), where the indicators stayed on and didn't flash at all and that was a 'common' problem where the flasher relay contacts weld together and need to be cleaned.

A simple fix but the relay resides on a large circuit board next to the fuse box and took a bit of gaining access to!

The flasher circuit should still be simple, (as long as Mercedes are not using the ECM to pulse the indicators instead of a simple flasher unit), and will consist of 12v being fed to the flasher unit and the other feed will go to the indicator switch.

The switch will then complete the circuit, to ground, via the left or right indicator bulbs.

If you only have a single 'repeater' lamp on the dash that will be fed from a point after the flasher relay but before the indicator switch.

If you have a L and R indicator repeator on the dash then these will be fed post switch.

Your fault description does sound illogical - hence the need for a little more detail!

If it is a basic system the flasher will require a specific current passing through it to make it flash at the correct rate as it is usually a bi-metalic switch that breaks as the current, (that is passing through it), heats it up and the bulb goes out!

It then cools and remakes the connection and the bulb goes on - ad infinitum!

If you replace one of the bulbs with an led upgrade the current drawn will be far less and the bi-metalic strip will not get as hot so the time it disconnects will be much shorter - hence a much faster flash!!

Apologies for the essay!

 

[bembo449]

Right , the car came with this fault , actually Intermittent, one of the bulb holder terminals was partially missing which i thought explained the fault, so i swapped it with the drivers side and it worked ok , obvs this could just be a coincidence as i said its Intermittent, got hold of another bulb holder which works fine in drivers side but hasn't changed the fault in the passenger side , ive tested the holders and bulbs in both and all are consistent, so that leads me to believe its either a SAM fault or more likely the unit itself, i assume that the plug wiring is the same for each side so i was thinking about swapping the drivers unit to see if that faults

 

[Martian]

Apologies for my VERY basic analogy which, (for all intent and purpose), was relatively useless!

I believe there may be several SAM's on each vehicle - monitoring sensors and switching things on and off - similar to the module on my old SLK!

I would, therefore, be inclined to power cycle the vehicle, (thus resetting all of the SAM logic), and see if normal operation is resumed!

Presuming that disconnecting and then reconnecting the battery doesn't cause other issues of course!

Otherwise it will be difficult to diagnose further without schematics of the SAM - or at the very least a flow diagram showing indicator input signals, (left and right), and indicator output feeds, (left, right and repeater).

Common problems with modules are the connectors as they can suffer water ingress and corrosion but very unlikely causing your issue.

There will be power transistors and/or FET's in these modules, (they switch the high currents on and off), and replace the 'old fashioned relays and are used for high speed switching, (ignition, injectors, etc), and these generate heat and cause dry joints to form on the circuit boards.

I very much doubt if is a poor joint or connector but a quick test would be to put the faulty indicator on and then gently tap the module in question.

if there is an electromechanical issue the fault may well come and go as you tap it!!

And of course there is your standard heat and vibration issues, (a vehicle engine bay is not the ideal place for sensitive electronics)!

If towbar electrics are fitted I suspect that the SAM may accommodate that too as there will be an additional loading if the circuit and there would need to be a feed for the warning buzzer too!

Even my bikes, (back in the very early 2000's), had CANBUS technology so the writing was on the wall, (way back then), for the majority of roadside repairs!

Apologies for another essay - I will get back to vetting the various E Class ads once again!

 

[Oldspanners]

Right , the car came with this fault , actually Intermittent, one of the bulb holder terminals was partially missing which i thought explained the fault, so i swapped it with the drivers side and it worked ok , obvs this could just be a coincidence as i said its Intermittent, got hold of another bulb holder which works fine in drivers side but hasn't changed the fault in the passenger side , ive tested the holders and bulbs in both and all are consistent, so that leads me to believe its either a SAM fault or more likely the unit itself, i assume that the plug wiring is the same for each side so i was thinking about swapping the drivers unit to see if that faults

Need to get hold of a wiring diagram from someone with WIS as the units themselves are working.
Hopefully a corroded connector.

 

[Botus]

my fathers 211 gets extra bulb for redundancy... it still flashes but the speed changes... replaced the popped bulb and it slows down, but only one of the two bulbs actually flashes, very strange... (front indicator..)

 

[M80]

Are they both equal brightness when on emergency flash?
It would seem there isn't enough load to satisfy the SAM, I would be looking for resistance in the cct somewhere, the plug to the light unit perhaps.
Poor contact within the lamp holder, perhaps?

I have fitted low cost lamps that have caused similar, after replacing the pair for better all was ok.

 

[alexanderfoti]

Internal flasher on the dash flashes quickly when there is an external bulb issue (it thinks/ or actually has a bulb out), but the remaining functioning bulbs will flash at the normal rate. The internal one serves as a notice to the driver to check the bulbs.

 

[bembo449]

Was that directed at me Alex , it appears we have a hi jack in progress

 

[alexanderfoti]

Completely lost

 

[bembo449]

Its my thread pal , were you giving me advise or botus on his fathers 211 ??