Mercedes-Benz SLK R170 2.3 ECU A0235454132 / 0261204746 – Early Signs of Failure, Replacement, and Programming

The Engine Control Unit (ECU), also known as the Engine Control Module (ECM), is the brain of your Mercedes-Benz. For the 2002 Mercedes-Benz SLK R170 2.3 petrol engine, the genuine ECU carries the part numbers A0235454132 and Bosch 0261204746. This module manages critical functions such as fuel injection, ignition timing, throttle response, and emissions.

When the ECU starts to fail, it can cause severe performance issues and leave your car unreliable. At Automan Spare Parts, we provide genuine, tested ECUs to keep your SLK R170 running at its best.

Early Signs of ECU Failure in Mercedes-Benz SLK R170

Here are the most common symptoms indicating your SLK’s ECU may be failing:

1. Check Engine Light Stays On

   • Persistent warning light even after servicing can signal a faulty ECU.

2. Hard Starting or No Start Condition

   • A failing ECU may not send the correct signals for fuel injection and ignition.

3. Engine Misfires and Stalling

   • Loss of power, uneven acceleration, or stalling during driving are strong signs.

4. Reduced Performance

   • Poor throttle response or hesitation when accelerating.

5. Unusual Fuel Consumption

   • Incorrect air-fuel ratio settings from a faulty ECU can reduce fuel efficiency.

How to Replace the ECU (A0235454132 / 0261204746)

Replacing the ECU on the Mercedes-Benz SLK R170 requires care and precision:

1. Disconnect the Battery – Remove the negative terminal to prevent electrical shorts.

2. Locate the ECU – In the R170 SLK, it is typically found in the engine compartment.

3. Remove the Old Unit – Unplug the wiring harness and unbolt the ECU from its bracket.

4. Install the Replacement ECU – Position the new ECU (A0235454132 / 0261204746), reconnect all wiring, and secure it.

5. Reconnect the Battery – Restore power and prepare for coding/programming.

Do You Need to Program the ECU?

Yes – in most cases, the Mercedes-Benz SLK R170 ECU requires programming after installation.

• The ECU must be matched with your vehicle’s VIN number, immobilizer system, and keys.

• Without proper coding, the car may fail to start or show error codes.

• Programming is usually done using Mercedes-Benz STAR diagnostic tools or by an experienced technician.

At Automan Spare Parts, we can guide you on programming requirements, and in some cases, we offer pre-programmed plug-and-play ECUs to save you time and hassle.

Final Thoughts

The Mercedes-Benz SLK R170 2.3 ECU (A0235454132 / Bosch 0261204746) is a critical component of your vehicle’s performance and reliability. Recognizing early failure signs—such as misfires, poor acceleration, or a persistent check engine light—can help you avoid major breakdowns.

At Automan Spare Parts, we supply genuine, tested ECUs for Mercedes-Benz and other leading brands, ensuring top quality at competitive prices.

✅ Order your Mercedes-Benz SLK R170 ECU today and restore your roadster’s smooth performance.