Details

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The Mercedes-Benz S221 with the M272 3.5L V6 engine (commonly referred to as the M272 E35) uses an Engine Control Unit (ECU) that manages all aspects of engine operation. Here’s a breakdown of the ECU and its role in this setup:

Vehicle Overview:

• Chassis: S221 (S-Class, 2006–2013)
• Engine: M272 E35 (3.5-liter V6, naturally aspirated)
• ECU Type: Bosch ME 9.7 (commonly used with M272 engines)

ECU (Engine Control Unit) Description:

1. Model:

• Bosch ME 9.7
  
• ME = Motronic Electronic (Bosch’s term for engine management)
• Controls both fuel injection and ignition
• 
  

2. Key Functions:

• Fuel injection control (directs fuel to cylinders with precision)
• Ignition timing (adjusts spark timing for performance and emissions)
• Variable Valve Timing (VVT) control (works with the M272’s variable camshaft system)
• Electronic throttle control (fly-by-wire, no physical throttle cable)
• Knock control (adjusts timing if engine knock is detected)
• Emissions system monitoring (EGR, catalytic converter efficiency, etc.)
• Limp-home mode (limits engine power in case of serious fault)
• OBD-II diagnostics (provides fault codes for scan tools)

3. Inputs & Sensors:

• Mass Air Flow (MAF) sensor
• Crankshaft and camshaft position sensors
• Oxygen sensors (pre- and post-cat)
• Coolant temperature sensor
• Throttle position sensor
• Knock sensors

4. Outputs:

• Fuel injectors
• Ignition coils
• Throttle actuator
• Variable cam timing actuators
• EGR valve
• Secondary air pump relay

Common ECU-Related Issues on M272 Engines:

• Throttle response issues
• Check Engine Light (CEL) with codes like P0016-P0019 (camshaft correlation)
• Camshaft adjuster magnet failures
• Balance shaft gear wear (a known M272 mechanical issue that can cause ECU error codes)

If you’re looking into tuning, replacing, or diagnosing this ECU, let me know and I can give you more detailed specs or wiring diagrams.