Classic Mercedes Benz diagnostics, consultations, inspections
Most Mercedes Benzes made in 1993 to 1995 have problems with throttle bodies also known as an electronic throttle actuator or ETA. Most ETA’s problems are due to shorting wires inside ETA loom and some due to internal component failures. When ETA fails car goes into so called “ Limp Mode”. On this page you find common symptoms of faulty throttle body.
There are ASR and Non-
Cars that are not equipped with ASR option have slightly different symptoms-
In both ASR and non-
Throttle bodies made in 1993 for 600SL ONLY and all others made in 1994-
At Mercedes dealership, new ETAs prices range from $1500 up to $5400 for some V12 models each. Some of them are no longer available. And it doesn’t make sense to buy used ones as they use same biodegradable wiring insulation that can fail pretty fast. Even if ETA worked fine in the car it came from wiring fails as loom gets bent and twisted during removal. I know many people who lost money buying used ETAs that failed either right away or after some time. In the end they had their original ETAs repaired.
Some small percentage of ETAs, about 5%, have internal parts failures. One of my V12 throttle body had an internal motor failure. Motor brushes became stuck and brush holder melted. Unfortunately, that motor could no longer be repaired. But I have repaired many motor brushes, electromagnetic clutch coils, replaced potentiometer metal sliders. Before rewiring ETA internals would need to be checked first
One can check the internal wiring insulation by making 2” incision along the center of actuator loom. Outer wiring cover can be pulled apart and wires will be visible. Also, you can check the production date of some throttle bodies. Scroll down for throttle actuators general information video, removal instructions, and pictures of failed wiring insulation. And feel free to contact me for more information.