Auto opening boot -sometimes doesn't

[bluespit]

I have a 2009 w204 estate with the power operated tailgate open and close. It always closes ok but sometimes it doesn't open. It always tries to open, from the remote, door button and tailgate lock. But sometimes it opens only about 10mm then stops or recloses. Sometimes works second time, sometimes takes 3 or more goes.

Any ideas please?

Cgeers

 

[brandwooddixon]

A common cause of this is that the gas struts become weak.

I'm not too sure about estates, but my CL had the same problem.

The motor mechanism is attached to one side of the boot, this means that the strut on the opposite side has to work harder and as it becomes weakened through age they offer less assistance to the motor.

The boot then doesn't open squarely putting more strain on the motor, which will cut out.

A sure sign of a weakened strut is that if you give the mechanism a helping hand (and not much mind) the boot will open fully.

Struts are about £15 and an easy DIY fit (around 5 minutes) requiring a small flat blade scre driver to remove the clips on the original. My dealers always keeps the struts for the offending side in stock, although to be fair they're the same on each side it's just that the clip fits the other way around on the opposite side.

 

[bluespit]

Hmm, if I try to help it at the tailgate handle it usually just closes again but I guess a strut is a cheap fix to try first

Thanks for the pointer

Any others?

 

[Mark@RMK]

It could just need re normalising with STAR. It resets its shut and open sensors and re calibrates it!

Mark

 

[brandwooddixon]

Hmm, if I try to help it at the tailgate handle it usually just closes again ...QUOTE]

Don't grip the handle if that has an opening switch in it. Just grip the door elsewhere and give it a little tug to see if it helps.

 

[television]

I think you have a dirty micro switch on the door lock , or is the sensor 380 dirty/faulty

The gas struts can fail in the cold weather 150

 

[brandwooddixon]

One point to make when fitting new struts. Have a look at the orientation of the body mounted end and compare it to the new one before fitting. I had to move the circlip around on one of mine when I replaced both, as even though it was sold as the offside strut it had the circlip in the nearside position.

 

[whitenemesis]

The 219 power operated boot is normalised in a similar fashion to the windows/sunroof, one doesn't require STAR. Could it be the same for the 204?

 

[bluespit]

Thanks for the above suggestions, can you tell me where the possible dirty micro switch is please? I'll try the suggestions this weekend.

Cheers

 

[television]

The switches are built into the locks, I was thinking about this last night in bed and one other member had this trouble, but I cannot find the post.

This door has to open in a pre determined time or it will close again.

Its very simple to remove a gas strut by just unhooking the spring clip then try pushing it against a wall and you should not be able to compress it at all.

Now if the car was put on STAR it should bring up what is wrong and it could save a lot of work

 

[brandwooddixon]

To be truthful, if you grip the edge of the boot as it pops open and all it needs is a light assistance to open then I'd go with weak struts. It only takes a moment to try. Stand at the back of the car trigger the remote opener and see.

When the struts are weak the boot will pop open a short way to the point where strut assistance is required. If it can't open beyond that point within a set time then it will give up and close again. You'll hear the motor straining before it gives up.

 

[bluespit]

Update

Since posting I've been opening the boot with the remote key and a gentle helping hand and it's worked every time. I'll keep doing this for a week or so and then I shouldmknowmfor certain. New gas struts likely though. Thanks for the heads up chaps. £15 from Mercedes? I'll be amazed!

 

[brandwooddixon]

Okay, well maybe £20. I'd have to find out my receipt to know for sure.