2013 CLS - Gearbox Issue?

[E55BOF]

It's a 2013 CLS (Dyslexia Lures KO... ), a 350 CDI on 70K miles.

I've had what may be a variation of limp mode, three times so far in 3000 miles; it feels like limp mode, from what I've read, but see what you think.
It happens right from the cold start. Pulling away, the car revs higher than normal before shifting up, and only accelerates on light throttle; no torque worth mentioning. It revs to about 2500-3000 rpm, no higher, and barely accelerates beyond about 2000. I floor the pedal, and it still barely accelerates, and there's no downshift.

The first couple of times, I pulled over after a mile or so, switched off, then switched on again, and normal operation was restored.

This last time, I was on the way to the office in heavy, fast-moving motorway traffic, and as the car would eventually creep up to 80-85 mph, I left it like that and kept going. I wouldn't say I was using any more throttle cruising steadily at that speed than normal. It wouldn't change down at all on the paddles, and when the speed dropped enough for it to select sixth automatically, it wouldn't change up or down on the paddles, and was very reluctant to change gear at all. Downshifts as the speed dropped were quite harsh, too.

I came off the motorway after twenty miles, stopped and switched off, then restarted, but this time, no change. The rev counter flared by about 400-500 rpm once or twice on (automatic) gear changes, and there was still no power.

Seven hours later, next cold start, everything was normal. I've started it about half-a-dozen times since then; normal every time.

It's never thrown up an EML, and the iCarsoft found no fault codes (current, stored or pending) in the transmission ECU or the shift control module. Could that happen with a failing electroplate?

It's not battery-related; the car had a brand-new battery less than 1000 miles ago to cure (which it did) difficulty in getting it out of Park after a cold start. I don't think it's a low fluid problem, as the fault is very intermittent.

Does anybody have any ideas?

 

[Tanny100]

Definitely limp mode matey. My car is currently doing the same after an ECU remap. I have reduced power, almost no turbo boost at all, cannot rev past 3k rpm (feels like a rev limiter), car does not shift up as it should. Off and on again and it’s back to normal.

As to the cause - I don’t know. Star will tell you I’ve learnt. My generic scanner doesn’t show any codes either.

Mine I think is related to my map.

 

[E55BOF]

Thanks for that; you may well be right. The iCarsoft is not a generic scanner, though; it is Mercedes-specific. What did STAR tell you about yours? How often does it do it, and does the problem only ocur on a cold start?

Who did your remap? Mine has been remapped too, by MSL; they know what they're doing, as thousands of satisfied customers will testify, and they've done lots of OM642s, so it may not be down to the remap.

 

[Tanny100]

Thanks for that; you may well be right. The iCarsoft is not a generic scanner, though; it is Mercedes-specific. What did STAR tell you about yours? How often does it do it, and does the problem only ocur on a cold start?

Who did your remap? Mine has been remapped too, by MSL; they know what they're doing, as thousands of satisfied customers will testify, and they've done lots of OM642s, so it may not be down to the remap.

Aah well I’ve not had a chance to have it diagnosed with Star yet. It’s just something I’ve read whilst researching.

I’m currently waiting on Superchips to get back in touch and hopefully put the car back to stock as soon as possible as I’m certain my car is going into limp mode due to a bad map.

 

[Tanny100]

Just read your post again properly mate. I’m certain my issues are map related as I got the error code P062F which is an EEPROM fault I.e. the writable part of the ECU. Superchips came out and cleared it but the car is still going into limp mode intermittently since then.

 

[E55BOF]

Wish I had an error code to go on...

 

[markjay]

Take it to Wayne Gates in Harrow (West London)?

 

[E55BOF]

Next Monday. Terry's as baffled as I am at the moment, due to the lack of a fault code. His first thought was gearbox electroplate, but that should throw up a code; a full STAR may come up with something the iCarsoft can't detect. I can't think it's anything other than electrical.

I'm carrying the iCarsoft in the car at the moment, with the cable permanently in the diagnostic socket; if it happens again, I'll plug it straight into the unit before I switch off and see if there's anything there.

 

[phobos]

Hi E55BOF, it does look like an TCM issue as the the gearbox is not allowing to shift. One thig I would test as well, just to put mind at ease. I have issues before where I thought the there was sometyhing goin on with the TCM on my car as the shifts were harsh and something it would kangoroo ( especially accelarating after a traffic light - not racing just a brisker accelaration ) and I was convinced that it was TCM..
It turns out my turbo actuator was playing up. Replaced it and all is well.

During this time, there were NO codes / errors picked up my STAR.

 

[suty455]

fwiw my blocked DPF caused the exact same issue

 

[E55BOF]

The DPF is not and never has been blocked.

It's almost three months and two thousand miles, and the glitch hasn't recurred.

 

[suty455]

The DPF is not and never has been blocked.

It's almost three months and two thousand miles, and the glitch hasn't recurred.

Fine didnt say it was but its the exact same issue and same engine box etc, when it did a dpf clean previously it behaved very similarly as well but it would of course pass 3k, perhaps you didnt complete a clean cycle on the last shutdown and it got itself in a loop, when it had a dpf cold starts were awful for the first 10 minutes it idled faster than norm at 900 ish rpm and gear changes were harsh 1-2 on a trailing throttle plus it changed at 1500+ rpm more like 2000, perhaps you are now doing more miles to allow it to clean more frequently, I dunno just describing my own experience.

 

[E55BOF]

Did it again today, but sort of mirror image... Definitely not limp mode. Responding normally to the throttle, except it was revving higher than normal and wouldn't drop below 2000 rpm, or change up into 7th on the paddles (I was doing about 65). I don't normally use Sport mode; the box was in Eco mode.

This time I tried changing modes, which I hadn't before. Sport mode - fine; into Manual mode - no Manual mode... Back to Eco mode - still doing it.

Pulled over, turned off, restarted, and all was well. Still no fault codes.

 

[suty455]

have seen it mentioned that the DPF sensor can cause similar issues as it reads the DPF as blocked but it is not

 

[E55BOF]

I really do not think that the issue can be in any way related to the DPF. How could that cause selection of Manual mode on the gearbox to play up, no letter 'M' on the instrument display and no change of gear with the paddles? The problem is intermittent, and almost certainly electrical, and within the gearbox and gear selection mechanism.

 

[Larkone]

Until you get in on STAR and get the live data read you are just guessing

 

[E55BOF]

The difficulty there is that it happens very rarely, about once in a thousand miles or so, and unless when it does happen I can keep the engine running until I can get it on a STAR, after the next restart it will be fine again.

 

[AndrewOl]

This is very similar to what went on with my 2006 GL. No eml, no codes on icarsoft. When Pentangle plugged Star in they could see codes in the TCU indicating an electroplate fault. The car was running normally but the codes were stored. Electroplate failures on the early 7g boxes are fairly common, mine occurred shortly after a gearbox service which is not unusual. Thought the later boxes were more reliable. I have a 2010 car now and hoping not to go through that pain again.

 

[E55BOF]

I'm thinking the same problem with mine, and it, too, had a transmission service fairly recently - February 2020, but less than 10K miles ago, at MSL immediately before the last remap. Provided it doesn't start to play up more frequently, when it goes in for routine service in February I'll get Terry Gates to read the codes, and I won't be too surprised if it needs the electroplate doing.

 

[AndrewOl]

Just out of interest, my A207 has the same engine. The 236 early version euro 5. Has the remapping you have done been worth it? MSL get a good name and say they can get another 50bhp out of it which I think it would make it feel quite quick. It’s ok now so a bit torn. Were you back for more or did you have issues with the map?