Where is the diagnostic system on my 1994 mercedes on 1994 Mercedes-Benz S420

I'd like to hook up a diagnostic system to get codes and troubleshoot why my engine, abs light is on, and also the speed odometer doesn't work

Asked by for the 1994 Mercedes-Benz S420
Two sites to look at There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate
Also look at
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Diagnostic work is difficult. Our shop in Vallejo works on European models. Call Adrian at Milt's Service Garage on Monday and make an appt. (707)643-7548
Like Hal said diagnostics is difficult. If in Walnut Creek call Contra Costa Smog. We specialize in difficult diagnoses 925-947-2555 If you failed the smog check you may be elidgible for C.A.P. money upto $500.00.
To fix your ABS light, speedometer and fuel efficiency, just replace the 10 amp fuse located in a module box under the hood on the passenger's side close to the firewall. Remove the four screws that hold it and you will see a module that has a small plastic lid that houses four 10 amp fuses and one of them is blown. Just replace it and that's it.
The connector for diagnostics is under the same big lid and is round in shape.
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