I have an idle problem that's been bugging me for a while now. When the engine is hot, and the car is stationary and in N or P, the idle will slowly rise to about 1500rpm and stay there.

It certainly isn't a problem with the cable or the idle setting, as when cold the engine is about 500-600rpm.

So I'm thinking something in here is getting a bit toasty, or perhaps is going near-open-circuit when hot. Any pointers, other than a faulty throttle pot (too expensive to guess at)?

Front to back.
Relay module K40 (power supply) is the front one with the fuses.
Next is the trans computer (EGS), then the engine control module (IFI), & last the traction system computer (ASR or ETS).

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Thanks for this picture and response. I was just looking for a the K40 relay as I'm trying to sort a friends '96 E300. Hmmm, computers are on the opposite side from mine in a right hand drive car, aren't they...? Had me confused there for a moment!