I’ve just had a French MOT equivalent on my car (a 2007 W164 ML63) and it’s failed due to an emissions issue. On a code reader it presenting fault code 3699 which says ‘Fuel Pressure Regulation Limit Exceeded’. A quick look at the possible cause of this leads to a number of possibilities with the fuel pumps and surrounding components. I had 2 new fuel pumps installed four years ago (20,000 ago miles, pre covid era) so I suspect it isn’t these specifically at fault. However, I have no access to additional diagnostics to investigate further where I now am (south of France) and I can’t afford to start experimenting with replacement parts that might fix it.
So my question is, has anyone else experienced this and what was the resolution if not the pumps themselves? I’m suspecting (hoping) that maybe replacing the fuel filters might be the resolution. They’re hard to get hold of and the price seems to flux significantly based on OEMs vs limited replacement parts (and their lack of).
Views and advice from anyone that’s had similar is appreciated. I’ve got two months grace to resolve it with the French system. I just don’t have the budget to try random options and hope.
Thanks in advance.
So my question is, has anyone else experienced this and what was the resolution if not the pumps themselves? I’m suspecting (hoping) that maybe replacing the fuel filters might be the resolution. They’re hard to get hold of and the price seems to flux significantly based on OEMs vs limited replacement parts (and their lack of).
Views and advice from anyone that’s had similar is appreciated. I’ve got two months grace to resolve it with the French system. I just don’t have the budget to try random options and hope.
Thanks in advance.
