Hi all
Hoping someone can shed some light here on issues I'm having with my SLK - 120000km (72k miles).

Symptoms:
1) Check engine light
2) Intermittent BAS/ESP light
3) Very very slow sometimes - but sometimes it runs fine.

History:
Replaced noisy supercharger clutch bearing a year or two ago
Changed brake pedal switch a couple months ago
Changed battery last week

I took it to my friendly MB dealer who agreed to plug it in and give me a quick test log free of charge (yeah, surprised me too!)

Results:
P2600 (stored) - undervoltage - battery
P2520 (stored) - Feedback through the transmission protection is not maintained
P2023-004 (stored) - Relay for air pump (P0410)
P2024-002 (stored and current) - Y32 Air pump switchover valve - P0412
P20BE-002 (stored) Right O2 front sensor short to ground
P20BF-002 (stored) Left O2 front sensor short to ground
P2008-008 (stored) Heating of front O2 capacity too low
P2088-008 (stored) Heating of front O2 capacity too low
P207c (stored and current) Supercharger mechanical fault (omg)
B1040 (stored) Fault in CAN comms with MR engine control
B1041 (stored) Fault in CAN comms with traction control
B1417 (stored) left dual valve
B1231 (stored) coolant temp sensor
B1418 (stored) right dual valve


*gulp*

So now... I'm sure that some of those are the result of the duff battery.

However, I'm also suspecting some wiring harness issues - short to ground, and o2 sensor heating capacity on both O2 sensors at the same time - and intermittent...?

But will any of the above trigger the supercharger code? When it's working it works fine. Not overly noisy or anything... The service advisor told me that the SAI failures could trigger the supercharger not to work. He was trying to tell me the SAI injects air into the intake manifolds so I don't know how seriously I should take him.

I'm gonna try and inspect the O2 sensor harnesses tonight or tomorrow, and swear at the SAI switchover valve until it behaves.
What's that P2520 all about?

Sage advice will be greatly appreciated.