I'm battling a bizarre electrical issue and I'm unsure how to resolve it, even after reading every forum post available regarding the issue and troubleshooting / testing the issue for weeks. From my research I've gathered the issue (SRS, ABS, Horn and Wiper Failure) is usually due to a relay - or a fuse, a break in the circuit (15) or a failing multi function switch - and occasionally - low voltage.


I've triple checked every fuse under the hood, in the passenger compartment - and in the trunk as well as tested every relay (they all click when power is applied) but the issue persists.

I've replaced the multi function switch - neither the old one or the new one does anything when turned - but I've noticed the car will not start if it is disconnected - so I'm pretty sure that isn't the problem.


I have noticed a bit of strange behavior though:


- Fuses 52 and 58 have no power - even after being replaced with new fuses

- I'm getting P0620 - even though I'm getting 14.3+ volts from the alternator 12.6 from the battery (the alternator was replaced within the past few weeks)

- I'm also getting the 'display visit workshop' along with the SRS ABS Horn & Wiper Failure

- My Aux Water pump has zero power to it


I really have no idea what else I can try at the moment - any suggestions, tips or ideas are GREATLY appreciated.

Apologies - it is my ESP and SRS - NOT SRS and ABS (I mixed up my acronyms when posting and there does not seem to be a way to make an edit other than this)

First you need to get a MB scanner.. iCarsoft MB V1.0 can be picked up for a little over hundred bucks... Every time you unplug and plug something in , it throws a code.. A generic OBII scanner won't get it.. You'll probably find, you lost the com link to the front SAM.. Read and clear ALL the codes.. Then cross your fingers..

Thanks! @stevestar99

Question...

So I know there is the front SAM under the engine bay fuse box... as well as something people call the 'front SAM fuse box' which is inside the part with the external battery charger connection which contains heavy duty high voltage "unserviceable" fuses shown here:




I'm going to pull and clean the connections for the front SAM under the fuse box on the right hand side of the car and see what happens...


but I was wondering your thoughts on opening up that module on the left and doing some continuity testing

It's a waist of time... Without a MB scanner... You'll never, never, never, ever.. clear any faults... If you plan on working/fixing your car.. you must, got to have , no way around it, have a MB scanner.. Like I said, the more stuff you unplug, the more faults you are stacking up... That includes fuses...