W209 CLK stuck in Drive

[icbatbh]

Hi all,

Had my 2006 CLK350 for a few weeks now, and have covered just under 1,000 miles with no issues until this morning.

When I was driving I noticed that the car wasn't changing up from either 3rd or 4th gear. I switched from 'comfort' to 'manual' mode but was unable to manually change gear (there was a 'D' on the display instead of the usual gear number). I came to a stop at some traffic lights and after that the car would not pull away. It was revving quite high (about 3k rpm) but would not exceed about 5mph. I pulled to the side of the road and tried to put it in park but the gear stick wouldn't move, it was stuck in the drive position. I could turn the engine off, but not the ignition and I couldn't remove the key either. After about 5 minutes I started the car and everything seemed to work fine again.

The car is booked in at my local indie tomorrow anyway as I'm getting another key for it, and I'll get them to check the fault codes but just wondering if anyone has a rough idea of what the problem is. Eg whether it's a minor component or if the gearbox is going to grenade itself.

 

[IanW]

This sounds like the problem I had with my CLK at the start of this year. IIRC, the fault codes pointed to the ESL (electronic shift lock/lever) - the electronics and solenoids below the gear shift lever.
Apparently a common problem with the older versions where the gear lever position is sensed by a potentiometer and metal 'fingers' scraping against it. Mine (and I suspect yours) use optical position sensing.
Being unable to remove the key or get out of drive is because the ESL has not released the relevant solenoids.
I was able to remove the ESL (after dismantling the centre console), re-solder a number of joints that looked suspect and re-calibrate the position of the optical position sensor using my iCarsoft fault code reader. Touch wood, it hasn't failed again.
I believe people like ECUTesting offer a test and repair service for the ESL units. Alternatively, you might be able to acquire a second hand unit - that was what Star Services of Reading suggested. The M-B parts catalogue shows the ESL as being a 'theft-coded' device, but it isn't.
I doubt that you have any problem with the gearbox at all.
Ian.

 

[icbatbh]

This sounds like the problem I had with my CLK at the start of this year. IIRC, the fault codes pointed to the ESL (electronic shift lock/lever) - the electronics and solenoids below the gear shift lever.
Apparently a common problem with the older versions where the gear lever position is sensed by a potentiometer and metal 'fingers' scraping against it. Mine (and I suspect yours) use optical position sensing.
Being unable to remove the key or get out of drive is because the ESL has not released the relevant solenoids.
I was able to remove the ESL (after dismantling the centre console), re-solder a number of joints that looked suspect and re-calibrate the position of the optical position sensor using my iCarsoft fault code reader. Touch wood, it hasn't failed again.
I believe people like ECUTesting offer a test and repair service for the ESL units. Alternatively, you might be able to acquire a second hand unit - that was what Star Services of Reading suggested. The M-B parts catalogue shows the ESL as being a 'theft-coded' device, but it isn't.
I doubt that you have any problem with the gearbox at all.
Ian.

Thanks for the information I'll bear this in mind. Would a problem with the ESL cause the car to not shift correctly as well, or would this likely only cause the shift lever to stay locked? I'm guessing both problems are related.

Quick update. Took the car for a drive and the gearbox worked beautifully in all three modes. I even put the car into Park several times and it didn't get stuck.

I noticed an oil patch on the ground where I'd parked. Opened the bonnet and there is indeed an oil leak, with a fait bit of oil on the alternator. I'm now wondering if this somehow affected the output which in turn interfered with the elevtronics in the autobox?

 

[IanW]

Would a problem with the ESL cause the car to not shift correctly as well, or would this likely only cause the shift lever to stay locked? I'm guessing both problems are related.

I don't recall mine failing to change gear correctly, but then I drove it very little until I'd fixed the problem - though I do recall it being intermittent. Fault codes will shed more light.

Opened the bonnet and there is indeed an oil leak, with a fait bit of oil on the alternator. I'm now wondering if this somehow affected the output which in turn interfered with the elevtronics in the autobox?

My engine is an M113, which leaks like a sieve, so everything under the bonnet has to work when covered in oil!
I don't have 'comfort' + 'manual' modes; mine are 'comfort' and 'sport', but I did notice that if D+/D- stopped working, then it would be locked in Drive.
Also, my car has a secret hole in the central storage bin - insert a biro, push and it releases the 'Drive' locking solenoid. I gather later CLKs may not have the feature. A BIC is now a permanent feature of my in-car toolkit!

Ian.

 

[icbatbh]

Just an update in case anyone encounters the same issue in the future. It's a problem with the transmission control unit, which has had to be sent off to be fixed. Will update further with cost to rectify as it's gone to my local independent garage.