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-S-9901A
Model All (Light transporter)
Overview
This document contains the following information:
- General
- Function requirements
- Function
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 above 30 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 420 | PE30.30-S-2501-97VRA | |
| Additional basic functions | |||
| Increase speed, basic function | GF30.30-S-1000A | ||
| Reduce speed, basic function | GF30.30-S-1001A | ||
| Traffic sign recognition, basic function | Model all (Light transporter) with code JA9 (Traffic Sign Assist) |
GF54.30-S-9901A | |
| Detailed information | |||
| Traffic sign recognition, detailed information | Model all (Light transporter) with code JA9 (Traffic Sign Assist) |
GF54.30-S-0022-01A |
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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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