Hi all,

This just happened about 30 minutes ago. Went to refuel and put a full tank of 98 in the car. Car is a 1996 e320 w210, m104 engine.

After i had finished, went to start and the immobilizer lights flash. Car then cranks but no start.

Turning the ignition off -> on and waiting 30 seconds, the lights stop. Turning ignition off -> on once more, the car starts .

Any idea what could possibly cause this? Some sensors in the fuel tank? I can't find any other threads on this anywhere online.

While its not super urgent as the car does eventually start, i would like to know what causes this and fix it asap.

Thanks,

Max

Anyone? Wanting to get this resolved.

This happened to me when I was running errands using the '96 E300 I had for a while. What cleared the problem, for me, was using the blade key in the driver's door to cycle the locking system. After that I never used the wireless remote again, and instead used a for real, physical key and never again had problems.

I don’t have any tips for you but all I can say is immobilizer problems scare me. I can visualize my 97 c280 (also m104) getting junked because of a malfunctioning immobilizer system.

I cannot see how refueling could mess up the immobilizer. The only connection I can think of is the pneumatic lock system. The power locks are related to the immobilizer. I’ve discovered this by messing with my door lock switches and accidentally triggering the alarm. It’s all intertwined with the door lock button on the dash. And one of the vacuum actuators is on your fuel door. That is a stretch…I really cannot see how opening your fuel door and putting gas in triggers the immobilizer.

Is there some kind of switch that checks to see if somebody siphons your gas?

Is this problem repeatable? Or has it only happened once?

Is it possible there is some kind of electronic problem in your key? Maybe turning the key is shorting out the board in the fob? Or maybe you went in your trunk and activated the security system through the antenna loop around the key? There is a way to deactivate the immobilizer this way n my c280 but I’m not sure if the 96 has this. The idea was that if you had the blade only key you need a way to deactivate the alarm before getting in the car. Of course my silly car doesn’t have a key hole on the drivers side.

__________________
79 300TD “Old Smokey” AKA “The Mistake” (SOLD)
82 240D stick shift 335k miles (SOLD)
82 300SD 300k miles
85 300D Turbodiesel 170k miles
97 C280 147k miles

Just happened again today when i went to refuel, but not the week prior.

I have a spare key, perhaps ill try with this one and see if it changes anything.

Same with my car, for whatever reason the key hole is on the passengers side (RHD car) but it would be drivers side for a LHD car.