R129 MAS Module - car not starting / diagnostics not working

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Feb 9, 2010
Evening all,

i have a 1991 R129 300 SL-24 and have been incurring intermittent faults which cause the car to die and leaving me stranded. When trying to re-start the car it fires briefly on first attempt and then dies again. It can be a couple of days before the car starts again without any intervention. I managed to complete a 90 mile journey before it failed again. This is the third time that it has happened.

When doing the diagnostics on the MAS module (pin 14), i note that i don't get any faults coming up on the reader, nor do i get the single light to tell me that there are no faults. This leads me to think that there is an issue with the MAS module.

Has anyone had any issues like this before?

Kind regards


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