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.
2021 Mercedes Benz CLS450 BaseFACTORY OEM SERVICE PROCEDURE
Electrical System - Engine - 257 Chassis
- General Information
- Basic Knowledge
- Testing & Repair
- Remove/Install Ignition Coils - AR15.12-P-2003MSA
- Remove/Install Crankshaft Hall Sensor - AR15.12-P-2136MSA
- Remove/Install Intake Camshaft Sensor - AR15.12-P-2146MSA
- Remove/Install Exhaust Camshaft Sensor - AR15.12-P-2147MSA
- Remove/Install Left Front Knock Sensor - AR15.12-P-2186MSA
- Remove/Install Left Rear Knock Sensor - AR15.12-P-2187MSA
- Remove/Install Fuel Injection System Engine Wiring Harness - AR15.18-P-0003MSA
- Remove/Install Crankcase Engine Wiring Harness - AR15.18-P-0006MSA
- Remove/Install Cylinder Head Engine Wiring Harness - AR15.18-P-0007MSA
- Disconnect/Connect Engine Wiring Harness To Remove Engine - AR15.18-P-1000-05MSA
- Tightening Procedure Of Integrated Starter Alternator - AR15.40-P-0003-01MRT
- Determine Integrated Starter Alternator Gap Between Stator And Rotor - AR15.40-P-0003-03MRT
- Perform Resistance Measurement Of Coils Of Integrated Starter Alternator - AR15.40-P-0003-04MRT
- Detach/Attach Tool For Installation/Removal Of Integrated Starter Alternator - AR15.40-P-0003-05MRT
- Remove/Install Integrated Starter Alternator - AR15.40-P-0003MSA
- Remove/Install Integrated Starter Alternator Control Unit - AR15.40-P-0004MSA
- Remove/Install Coolant Temperature Sensor - AR15.60-P-2712MSA
- Test & Adjustment Values
- Maintenance
- Torque Specifications
- Tightening Torques: Passenger Cars: Electrical System - Engine - BA15.00-Z-9999AZ
- Spark Plug - BA15.10-P-1000-01C
- Knock Sensors - BA15.10-P-1000-02B
- Crankshaft/Camshaft Position Sensor - BA15.10-P-1000-03I
- Ignition Coil - BA15.10-P-1000-04A
- Engine Wiring Harness - BA15.18-P-1000-01MRT
- 48V On-Board Electrical System Subharness - BA15.18-P-1000-03MRT
- Integrated Starter Alternator - BA15.40-P-1000-02MRT
- Temperature Sensor - BA15.60-P-1000-02MRT
- Wiring Diagrams
- Special Tools
- 124 589 09 63 00 Ohm Decade - WS15.00-N-0009C
- 201 589 00 99 00 Electrical Connection Kit - WS15.00-N-0014C
- 124 589 09 63 00 Ohm Decade - WS15.00-P-0009C
- 602 589 00 10 00 Socket Wrench - WS15.00-P-0015B
- 000 588 03 19 00 Load Tester - WS15.00-P-0027B
- 256 589 01 31 00 Support Fixture - WS15.00-P-0029B
- 256 589 01 23 00 Gauge - WS15.00-P-0047B
- 278 589 00 09 00 Spark Plug Wrench - WS15.00-P-0065B
- 256 586 00 09 00 Socket Wrench Socket - WS15.00-P-0070A
Factory Service Tools
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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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