The Mercedes-Benz W124 series, particularly models equipped with the four-speed automatic transmission, exhibit unique shift logic that may differ from modern automatic gearboxes. Owners of the W124 230E with an automatic transmission sometimes observe that the car starts moving in second gear instead of first. This is not a fault but rather a design feature intended to improve drivability, reduce wheel slip, and enhance comfort.
The Mercedes-Benz W124 series, particularly models equipped with the 722.3 and 722.4 automatic transmissions, exhibit a distinct shift logic that varies depending on the selected driving mode—Economy (E) or Standard (S). These modes influence gear engagement strategies, throttle response, and shift timing to optimize driving dynamics in accordance with efficiency or performance priorities.
Transmission Start Behavior: Second-Gear Start in Economy vs. Standard Mode
In both Economy and Standard driving modes, the W124 230E typically starts in second gear under normal driving conditions. This characteristic is a deliberate engineering choice by Mercedes-Benz to enhance smoothness, reduce wheel slip, and improve fuel economy.
1. Economy Mode (E) Behavior
- The transmission favors early upshifts to keep RPMs low, optimizing fuel efficiency.
- Kick-down response is less aggressive, requiring more throttle input to force a downshift.
- Second-gear starts are more consistently enforced, reducing torque output at launch to maximize comfort and traction.
2. Standard Mode (S) Behavior
- The transmission holds gears longer before upshifting, allowing for stronger acceleration.
- Kick-down response is more immediate, enabling quicker downshifts when additional power is needed.
- While the car still starts in second gear, throttle sensitivity in S mode increases the likelihood of engaging first gear under heavy acceleration.
How the Transmission Selects First Gear in Each Mode
Regardless of the driving mode, the W124 automatic transmission can engage first gear under specific conditions:
- When the accelerator pedal is fully depressed (kick-down activated).
- When the gear lever is manually placed in “2”, ensuring a first-gear launch.
- Under heavy load situations, such as climbing steep inclines.
Technical Factors Influencing Mode Differences
The Economy and Standard driving modes do not alter the fundamental hydraulic operation of the transmission but instead modify shift points and throttle response. Key components influencing these behaviors include:
- Vacuum Modulator: Adjusts shift timing based on engine load.
- Throttle Valve Linkage: Controls gear engagement based on pedal input intensity.
- Kick-Down Solenoid: Engages first gear when maximum throttle is applied.
Comparison With Other W124 Models
Other W124 models with automatic transmissions share this second-gear start characteristic, including the 300E, 260E, and 200E. Models with five-speed automatic gearboxes may exhibit more frequent first-gear starts, particularly in Standard mode, as these transmissions are tuned differently for performance.
Conclusion
Both Economy and Standard modes in the W124 230E enforce second-gear starts during normal driving, though Standard mode allows more aggressive throttle response and quicker downshifts. First gear remains accessible when needed, ensuring adaptability based on driving conditions.