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 CLA250 BaseFACTORY OEM SERVICE PROCEDURE
Electrical System -- Engine -- 118 Chassis
- General Information
- Basic Knowledge
- Testing & Repair
- Remove Install Crankshaft Pulse Ring - AR15.12-P-0001MFC
- Remove/Install Ignition Coils
- Remove/Install Crankshaft Hall Sensor
- Remove/Install Knock Sensors
- Remove/Install Wiring Harness For Alternator - AR15.18-P-0016MFG
- Disconnect/Connect Engine Wiring Harness To Remove Cylinder Head Cover - AR15.18-P-1000-04MFC
- Disconnect/Connect Engine Wiring Harness To Remove Engine - AR15.18-P-1000-05MFG
- Disconnecting And Connecting Harness At Starter - AR15.30-P-7100-03MFG
- Remove/Install Starter
- Tighten Alternator Screws/Bolts - AR15.40-P-0002-01MFA
- Check Regulator And Alternator
- Test Alternator Charging Current
- Remove/Install Alternator
- Remove/Install Belt-Driven Starter Alternator - AR15.40-P-5060MFA
- Remove/Install Alternator Belt Pulley
- Test Alternator Diodes
- Remove/Install Coolant Temperature Sensor - AR15.60-P-2712MFC
- Test & Adjustment Values
- Maintenance
- Torque Specifications
- Tightening Torques: Passenger Cars: Electrical System - Engine - BA15.00-Z-9999AZ
- Ignition System - BA15.10-P-1000-01C
- Knock Sensors - BA15.10-P-1000-02B
- Position Sensor - BA15.10-P-1000-03I
- Ignition Coil - BA15.10-P-1000-04A
- Starter - BA15.30-P-1000-01J
- Generator - BA15.40-P-1000-01W
- Integrated Starter Alternator - BA15.40-P-1000-02C
- Temperature Sensor - BA15.60-P-1000-01E
- Forms
- 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
- 278 589 00 09 00 Spark Plug Wrench - WS15.00-P-0065B
- 000 588 31 19 00 Load Tester - WS15.00-P-0077B
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
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.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
Comes to youSame-day available12-month warranty
Get a Free QuoteNo obligation. See pricing before you book.