Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Speed Control, Basic Function - GF30.30-P-9901A
Model All (4xWD)
Model All (CAR)
Overview
This document contains information on:
- General
- Function requirements
- Function
- Shutoff conditions
General
The speed control automatically accelerates and decelerates the vehicle to a specified value and holds this constant. The driver can remove his foot from the accelerator pedal. Speed control ensures relaxed driving. It is activated as soon as the driver defines a speed value.
Function requirements
- Engine running or drivetrain operational
- Vehicle in forward travel
- Vehicle speed over 20 km/h
Function
The speed control adapts the vehicle speed to the specified speed value and holds this constant. In doing so, speed control accelerates or decelerates the vehicle.
If the driver accelerates the vehicle with the accelerator pedal (e. g. to overtake), the set specified speed remains stored. Once the foot is removed again from the accelerator pedal, the speed control returns the vehicle to the stored speed value.
Vehicles with Driving Assistance Package:
Indicated speed limits registered by the traffic sign recognition system or location-related limitations from the navigation system can be adopted as the specified speed.
Shutoff conditions
Speed control shuts off under the following conditions:
- Brake pedal operated
- Electronic Stability Program (ESP®) shut off
- ESP® regulating.
- "Brake" request from a different vehicle assistance system
- Vehicles with manual transmission:
- Very low engine speed
- Engine speed near the maximum engine speed transmission in neutral
- Clutch pedal operated
| Function schematics | |||
| Regulate speed, function schematic | Model 118, 167, 177, 243, 247, 293 except code 233 (Adaptive cruise control Plus (DISTRONIC PLUS)) except code 239 (Adaptive cruise control Pro (DISTRONIC PRO)) Model 213, 238, 257, 290 as of model year 2021 except code 233 (Adaptive cruise control Plus (DISTRONIC PLUS)) except code 239 (Adaptive cruise control Pro (DISTRONIC PRO)) | PE30.30-P-2501-97A | |
| Model 118, 167, 177, 243, 247, 293 with code 233 (Adaptive cruise control Plus (DISTRONIC PLUS)) Model 118, 167, 177, 243, 247, 293 with code 239 (Adaptive cruise control Pro (DISTRONIC PRO)) Model 213, 238, 257, 290 as of model year 2021 with code 233 (Adaptive cruise control Plus (DISTRONIC PLUS)) Model 213, 238, 257, 290 as of model year 2021 with code 239 (Adaptive cruise control Pro (DISTRONIC PRO)) | PE30.30-P-2501-97B | ||
| Model 223, 297 | PE30.30-P-2501-97C | ||
| Model 192, 206, 214, 232, 236, 254, 294, 295, 296 | PE30.30-P-2501-97D | ||
| Model 464 | PE30.30-P-2501-97E | ||
| Further basic functions | |||
| Direction of travel selection, basic function | MODEL 243, 293, 295, 296, 297 | GF08.00-P-1002A | |
| Gearshift system, basic function | Model all with transmission 725.0/1 | GF27.60-P-1002B | |
| Increase speed, basic function | GF30.30-P-1000A | ||
| Reduce speed, basic function | GF30.30-P-1001A | ||
| Traffic sign recognition, basic function | Model all (CAR) with code 504 (Speed sign recognition) Model all (CAR) with code 513 (Road sign recognition system) |
GF54.30-P-9901A |
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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