W168 in limp mode

[area51]

Really hoping someone can help with this..

As per the title. I have a year 2000 A160 auto that has on two occasions gone into limp mode with a bit of a jolt while moving at low speed.

The gear position indicator then flashes on/off and the BAS/ESP light comes on. All faults disappear on restarting and the car then drives fine.

The fault codes that I got when this first happened are:
P0600-003 Historic. CAN fault with Y3/7 (?) FTC
C1201 Historic. BAS release switch A7/7s1
C1204 Historic. CAN fault in transmission from control unit N47/5

I changed the brake light switch as I have read that this can cause BAS/ESP faults.

Same codes on the second occasion except for C1201 which didn't reappear.

Not too sure where to start with this, all help much appreciated.

 

[ZZZZ]

I had this FTC fault on my old A160 W168 back in 2015 - as it was on a Service Care plan, Mercedes Roadside Assistance came over and did a full diagnostics - came up with a few secondary faults, but the main one was:
P1841 - Valve Y3/7y2 (pulse width modulated solenoid valve 3 shift) is faulty.

Forrera replaced the TCU with a reconditioned one (from ECU Testing, I believe), and it was like new after that.
I sold it a few months later, as I already bought the A200, but as far as I know, it is still running fine, with over 120k on the clock.

PS For some reason, I thought yours was a manual transmission, Chris?

 

[ajlsl600]

I had similer
with faulty shift unit. Module. Solved with unit I got from spare car I broke up for bits 18 months ago.. Can't remember if twas n47/5?

 

[ajlsl600]

N47/5 esp control I think?

 

[area51]

N47/5 esp control I think?

Yes N47/5 is the ESP module. I'm wondering if the BAS release switch is still at fault but didn't show up on the second scan?

Trouble is the switch is buried within the brake servo and taking that apart seems like a bad idea...

 

[ajlsl600]

Clear all. Having noted them down and try again. Be aware some fault can actually be wiring/plugs ect going to/from the item/module rfered to. For someone doing this on a regular basis. Less complex. For us, me anyway, it can turn out a real ballache. I generally get there. Just takes me, most times longer, my priority, keeping my Cash in pocket as much as poss. Good luck. Plse do post solution when you get to it.

 

[area51]

I had this FTC fault on my old A160 W168 back in 2015 - as it was on a Service Care plan, Mercedes Roadside Assistance came over and did a full diagnostics - came up with a few secondary faults, but the main one was:
P1841 - Valve Y3/7y2 (pulse width modulated solenoid valve 3 shift) is faulty.

Forrera replaced the TCU with a reconditioned one (from ECU Testing, I believe), and it was like new after that.
I sold it a few months later, as I already bought the A200, but as far as I know, it is still running fine, with over 120k on the clock.

PS For some reason, I thought yours was a manual transmission, Chris?

Thanks David, mine is automatic which I like. Manual transmission would have been a problem for me when I had trouble with my left knee a while back.

I reckon the TCU is most probably toast. I'll have a chat with ECU testing when they re-open.

 

[area51]

Clear all. Having noted them down and try again. Be aware some fault can actually be wiring/plugs ect going to/from the item/module rfered to. For someone doing this on a regular basis. Less complex. For us, me anyway, it can turn out a real ballache. I generally get there. Just takes me, most times longer, my priority, keeping my Cash in pocket as much as poss. Good luck. Plse do post solution when you get to it.

Thank you.

Luckily the codes do clear ok. I will take a look at the connector for the TCU first and of course post feedback (so frustrating when someone has clearly had the same fault with their car but don't then post the solution).

 

[ZZZZ]

Thanks David, mine is automatic which I like. Manual transmission would have been a problem for me when I had trouble with my left knee a while back.

Of course, I remember now.
I can't even drive the "stick", so not a choice for me, haha - it's got to be an auto

I reckon the TCU is most probably toast. I'll have a chat with ECU testing when they re-open.

Well, yours lasted a lot longer than mine(s) - the A190 from Japan I had in Nassau went at about 78k kms (!), the A160 above - at 107k miles - so not too bad, I guess.

Once you replaced the TCU, Forrera has a great video on topping up ATF on his YouTube page:
https://www.youtube.com/channel/UCifIgxc2DSRxAILlxKRoEwA

There's also one about removing the actual TCU too.