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Registered SLK32 AMG 2002
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36 Posts
Discussion Starter #1 (Edited)
SLK32 AMG loss of boost, BAS ESP light, no OBD2 errors

Hi,

2002 SLK32 with 125,000 km, running a 65mm DTK aftermarket supercharger pulley and applied DTK ECU tuning last year which made it noticeably more responsive. Car was running fine for a while.

Main issue I'm experiencing is that when I'm driving and depress the throttle to accelerate further, instead of a supercharger boost, sometimes the BAS/ESP lights both come on and the throttle response goes very weak. The car becomes very slow to accelerate and it feels like the supercharger isn't working at all. Problem is reset by turning engine off/on. No CEL.

The following codes WERE showing up in Torque Pro (prior to K40 fix):

Pending Fault - P0105 - Powertrain (Manifold Absolute Pressure / Barometric Pressure Circuit)
Pending Fault - P0410 - Powertrain (Secondary Air Injection System)

The MAP Sensor (possible cause of P0105) was replaced with a new one

Both codes were still coming up even after MAP sensor replacement, however K40 relay resolder fix appears to have fixed both.

No fault codes are now coming up in Torque Pro at all after over 200 km of driving, however loss of boost while driving + BAS ESP light is still happening.

Possible explanations seem to be wheel speed sensor tripping BAS/ESP or supercharger intercooler pump?
 

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Registered SLK32 AMG 2002
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36 Posts
Discussion Starter #4
Thanks.

The MAP Sensor (part# A0041533328) has already just been replaced, I assume there isn't a separate boost sensor on the SLK32? (Please correct me if I'm wrong, but I can't find any reference to it)

Just to add to the symptom description, sometimes I feel like there's a lack of boost even before the BAS ESP lights come on.

The problem also seems more likely to occur on longer drives. I drove 5 km twice a day for a week with no problems, but then BAS ESP and no boost happened on a 15 km drive yesterday.
@eheif described a similar problem in an old post https://www.slkworld.com/slk-r170-general-discussion/225041-slk32-amg-loses-boost.html, in case you're reading did you ever solve it?
 

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Registered 2002 R170 SLK V8 5.0
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2,026 Posts
Hi,

You need to get this read on SDS if that BAS / ESP light has been on, there will be other codes that the cheaper equipment is not seeing, these could well be having an effect on restricting Engine power.

HTH, Cheers Dave
 

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Registered SLK32 AMG 2002
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36 Posts
Discussion Starter #6
Hi,

You need to get this read on SDS if that BAS / ESP light has been on, there will be other codes that the cheaper equipment is not seeing, these could well be having an effect on restricting Engine power.

HTH, Cheers Dave
Are there any (paid) Android apps or PC/Mac apps that will read more through my OBD2 bluetooth interface than Torque Pro?

My local mechanic that I go to has some kind of tablet but I'm not sure if it's just an OBD2 scanner or does Star Diagnostics as well

I guess it's only Star if it connects to the round connector near the battery?
 

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Registered 2002 R170 SLK V8 5.0
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2,026 Posts
Are there any (paid) Android apps or PC/Mac apps that will read more through my OBD2 bluetooth interface than Torque Pro?

My local mechanic that I go to has some kind of tablet but I'm not sure if it's just an OBD2 scanner or does Star Diagnostics as well

I guess it's only Star if it connects to the round connector near the battery?
Hi,

Star, (SDS, DAS, XENTRY,) call it what you will has a decent Multiplexer unit that connects between Laptop and Car ...............

Like these :-

https://www.obdstore.co.uk/product/auto-diagnostic-laptop-toughbook-cf-19-tablet-pc-with-sd-connect-c4-mb-software/

https://www.obdstore.co.uk/product/mb-star-c3-mercedes-diagnostics-mulitplexer/

HTH, Cheers Dave
 

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846 Posts
I guess it's only Star if it connects to the round connector near the battery?



Your car has OBD2 under the dash by the bonnet release.
 

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Registered SLK32 AMG 2002
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36 Posts
Discussion Starter #9 (Edited)
I guess it's only Star if it connects to the round connector near the battery?

Your car has OBD2 under the dash by the bonnet release.
I know, I have a cheap ELM327 Bluetooth OBD2 interface that I've been using with Torque Pro.

What I meant to ask is, if my mechanic has a code scanner tablet that connects ONLY to the OBD2 port and NOT the Star / SDS port under the hood, is it still possible to read more detailed SDS codes via OBD2, or does Torque Pro already read everything that's possible via OBD2?

UPDATE: I took out my K40 relay board a few days ago and reflowed 2 solder pads that looked a bit dull (see attached image)

To my surprise, the P0410 code (which has been coming up forever) and the P0105 code which made me replace the MAP Sensor have stopped coming up.

No fault codes are coming up in Torque Pro at all after ~200 km of driving, including a lot of rapid acceleration.

HOWEVER, the issue with losing boost after a while and the BAS ESP light coming on is still occurring, so I guess I really need a full SDS read out as the next step.

Any ideas on what would cause boost to be disabled and the BAS ESP light to come on, while not raising any fault codes visible in Torque Pro?

The car still drives OK when it gets into this state. I can put cruise control on 100 or 110 km/h and it will keep driving smoothly, but boost is gone and acceleration is very slow (no immediate response to stepping on the throttle like there should be).

Every time I restart the engine, the BAS ESP light is gone and boost will work again for a little while - It will go like a rocket thanks to the DTK ECU tune & 65mm pulley. But then boost will stop working again at some point during the drive and the lights will come on.

I'm thinking it may be the ECU limiting things due to some sensor issue, rather than any of the supercharger parts actually not working?

Could it possibly be related to a resistor for the LED tail lights not being connected properly, which causes the bulb warning light to come on even though all bulbs are fine?
 

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Registered 2002 R170 SLK V8 5.0
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2,026 Posts
Hi,

Glad you have sorted the K40 and got rid of some faults.

I suspect there is an Engine Fault that your Torque is not seeing, and this may be communicating, (CAN Com Error) to BAS ESP, or could be vice versa, or maybe there is a fault in each system, but I'm going with communicated Errors right now, as the 2 events coincide !!

Car needs reading on a very decent bit of kit, I recommend SDS.

A little insight ..........

The cheaper the diagnostic kit the less codes / modules it will read.

I doubt Torque pro will read much more than a handful of Engine Codes.

SDS is the Dealer Machine, same software as used by Mercedes Main Dealers, it will access and do everything that the dealers can do, (well actually a clone machine with "Developer" enabled will do more than the Dealers can do) ................... Dealers do not have Developer Enabled, it is for factory R&D use only :wink:

SDS costs £400 upwards, but on R170 the basic £400 machine is all you need, perhaps an extra lead if your Car has the Round Pin Plug. AFAIK Post Facelift Cars do not need this extra lead.

Anything that costs less than that will not get anywhere near SDS, and expensive professional machines which cost 5 times as much will still only get 80% of codes in 80% of Modules.

IMHO SDS is worth every penny for a serious DIY'er, everyone I have spoken with who has taken the plunge and bought SDS agrees, and it pays for itself many times over for lots of reasons.

HTH, Cheers Dave
 

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Registered SLK32 AMG 2002
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36 Posts
Discussion Starter #11
Thanks. My local indy doesn't have STAR kit and another Mercedes specialist will charge me at least 150 AUD to run STAR once

An MB SD Connect Compact C5 Multiplexer box (presumably a clone) is available for 339 USD here, considering getting this

Newest MB SD Connect Compact 5(SD C4) Star Diagnosis with WIFI for Cars and Trucks

Would the C5 multiplexer connect to the 16 pin OBD2 port under the dash, or would I use one of the special connectors it comes with? (R170 2002 SLK32 AMG)
 

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Registered 2002 R170 SLK V8 5.0
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2,026 Posts
Hi,

Yes it does make sense to have this system, and I assure you you will be amazed and not regret the purchase, as others who buy "lesser" kit do !!

For many many reasons you will find that it is soooooooo much more that just a reader / resetter, and it will do everything you'll ever need on an R170 and many many other MB cars without needing an online subscription to MB !!

I am not certain that C5 is your best bet, personally for an R170 and any MB up to around 2012 MY C3 works great, C4 should be ok with the SDS's HHT Emulator used on many modules on the R170.

C4 is also cool when using it's wireless function, but just in case wireless drops, I never use the Wireless function for any programming or version coding works, they can also be connected to laptop via LAN lead, which normally comes with the C4 Mux and Lead Kit. Wireless is fine for Reading and Resetting, Live Data ("Actual Values"), Actuations etc etc :smile:

On your particular Post Facelift you will only use the 16 Pin OBD Type Connector :wink:

HTH, Cheers Dave
 

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Registered 2002 R170 SLK V8 5.0
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2,026 Posts
Hi,

@M4rCu5

I can vouch for Toni, he's a really sound honest guy.

I've never bought an SDS system from them, because I bought my first C3 based one good used from a previous MB owner, all fully working, and I built the 2017 C4 System myself by buying Mux and Leads from the factory in China, and I then built the singing and dancing super fast Dell laptop myself and bought a ready loaded to go HDD from a friend which is a custom 64bit Win 7 version that will do online stuff with late model cars via 3rd party / TV.

However I have bought JLR, Peugeot / Citroen and other machines off Toni Saleni, and one Sunday at around 5pm I had an issue with one machine, he answered my call immediately, came on TV, he couldn't sort it, but within a couple of hours his techie guy came on TV and fixed it, been faultless ever since, so yes his service really is 24 / 7 :wink:

Oh, btw, it is worthy of note that buying anything Chinesium off the likes of "Ali Baba and the Forty Thieves" is always a bit of a lottery with your hard earned Cash, especially when seeing the deals Toni and other like companies charge for hand picked and fettled machines that work plug and play right outta the box !!

If anyone is contemplating this route, buy it on a CREDIT Card then at least you can do a charge back if you get screwed over !!

HTH, Cheers Dave
 

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Registered SLK32 AMG 2002
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36 Posts
Discussion Starter #15
Now have a laptop with Mercedes Xentry / DAS set up and a C4 Multiplexer all working

I cleared all faults and reproduced the issue with the SC being disabled and the BAS/ESP light coming on after a slightly longer drive. DAS fault codes from this one test drive as per attached screenshot

I seem to have a bad oil sensor as those 3 codes related to it come up again even after a short drive if I clear faults.

The P2027-001 (IAT too high) hints at bad IC pump I think? I've been recommended to replace it with the Bosch 0392022010 part and also change the fuse for it from a 5 amp to a 7.5 (I confirmed the original fuse is not blown)

P2023-004 (P0410) could still be a bad K40 solder joint or actually a bad relay - maybe need to reflow more of the solder joints, or maybe something actually wrong with air pump?

P207C Supercharger Mechanical Fault sounds potentially worrying, I wonder if this code is set by ECU when SC is disabled for temperature reasons or because it has actually detected a mechanical problem with it - Any experience with this?

Weirdly there seem to be no faults actually related to BAS or ESP

On a shorter test drive where the SC was not disabled and BAS/ESP didn't come on, P2027-001 (excessive IAT temp) was raised in isolation without the P0410 and P207C codes coming up so it does seem plausible the IC pump is maybe not running at all - Any idea how I can confirm it's dead?
 

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Registered SLK32 AMG 2002
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36 Posts
Discussion Starter #16
UPDATE: Was looking at the wrong fuse, fuse #23 is the correct one for the IC pump and was in fact blown

Replaced the blown 5 amp fuse with a spare 10 amp and cleared all faults in DAS

Will see if this solves excessive IAT and losing boost
 

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Registered 2002 R170 SLK V8 5.0
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2,026 Posts
Hi,

I think it is a distinct possibility that the "S/C Mech fault" is a "red herring" , likely a direct result of the ME shutting down the Boost when IAT rises above spec :wink:

If you are happy your IC Pump is working and no airlocks in coolant, clear all codes and go again, just keep drilling away at it ;)

What Codes are you getting in BAS / ESP I do not see anything related in your ME Codes ???

How are you getting on with SDS ?

Good on you for biting that bullet, it can seem a little daunting at first and be a steep learning curve for some, but the more you use it the more in depth functions you will find :wink:

HTH, Cheers Dave
 

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Registered SLK32 AMG 2002
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36 Posts
Discussion Starter #18
Thanks @Dave2302

SDS is coming in very useful - Showing a lot more codes and detail than is visible in Torque Pro.
I got an "MB SD Connect C5" multiplexer from obdii365.com which is really a C4 clone with some extra features in a C5 lookalike case.
I installed the provided SSD drive with the V2019.07 software in a Dell Latitude E6410 laptop. Mercedes DAS is working great via Ethernet and Wifi.

The P2027-001 (IAT too high) code has recurred since I replaced the blown IC pump fuse - Intake air temperature was 97 / 90 degrees C looking at the stored fault details

However the P207C Supercharger fault code has not recurred so far, and there has been no loss of SC power with BAS ESP light, though I haven't driven much yet

Today I noticed something else that seems very wrong and potentially related, this small hose that plugs into a bigger air intake pipe was unplugged - Plugged it back in (should there be a clamp or something?)

What exactly does this do and what impact would driving with it unplugged have? Not sure if it came loose by itself or if the mechanic forgot to reconnect it when he replaced the MAP Sensor
 

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Registered 2002 R170 SLK V8 5.0
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2,026 Posts
Hi,

If this engine has an Airflow meter (I'm not sure), but if it does and that hose enters after AFM, that will have a serious effect on metered air and can cause all sorts of problems ;)

HTH, Cheers Dave
 
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