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 BMW Z4 sDrive30iFACTORY OEM SERVICE PROCEDURE
Engine Electrical System -- Repair (G29)
- 12 00 General Information
- 12 12 Spark Plugs
- 12 13 Ignition Coils
- 12 14 Crankshaft Sensor, Camshaft Sensors, Knock Sensors, Engine Control Module
- 12 14 521 Replacing the crankshaft sensor (Z4 sDrive30i)
- 12 14 523 Replace intake camshaft sensor (Z4 sDrive30i)
- 12 14 524 Replace exhaust camshaft sensor (Z4 sDrive30i)
- 12 14 550 Replacing the engine control module (Digital Motor Electronics control unit)
- 12 14 602 Replacing knock sensor (following vehicle diagnosis) (cylinders 1-2) (Z4 sDrive30i)
- 12 14 604 Replacing knock sensor (following vehicle diagnosis) (cylinders 3-4) (Z4 sDrive30i)
- 12 14 700 Coding the control unit (DME)
- 12 14 705 Programming the control unit (DME)
- 12 14 521 Replacing the crankshaft sensor (Z4 M40i)
- 12 14 523 Replace intake camshaft sensor (Z4 M40i)
- 12 14 524 Replace exhaust camshaft sensor (Z4 M40i)
- 12 14 602 Replacing knock sensor (following vehicle diagnosis) (cylinders 1-3) (Z4 M40i)
- 12 14 604 Replacing knock sensor (following vehicle diagnosis) (cylinders 4-6) (Z4 M40i)
- 12 31 Alternator
- 12 41 Starter Motor
- 12 42 Starter Motor Positive Battery Cable
- 12 42 540 Replacing the safety battery terminal (SBK)
- 12 42 651 Removing and installing/replacing the positive battery cable remote positive terminal alternator (Z4 sDrive30i)
- 12 42 652 Removing and installing/replacing the positive battery cable remote positive terminal starter
- 12 42 651 Removing and installing/replacing the positive battery cable remote positive terminal alternator (Z4 M40i)
- 12 51 Engine Wiring Harness
- 12 51 210 Replacing the wiring harness section for injectors and ignition coils (Z4 sDrive30i)
- 12 51 215 Replace the wiring harness section for the Valvetronic servomotor (Z4 sDrive30i)
- 12 51 235 Remove and install/replace Module 1, sensor system engine wiring (Z4 sDrive30i)
- 12 51 240 Remove and install/replace Module 2, sensor system engine wiring (Z4 sDrive30i)
- 12 51 245 Remove and install/replace transmission module engine wiring, (Z4 sDrive30i)
- 12 51 210 Replacing the wiring harness section for injectors and ignition coils (Z4 M40i)
- 12 51 235 Remove and install/replace Module 1, sensor system engine wiring (Z4 M40i)
- 12 51 240 Remove and install/replace Module 2, sensor system engine wiring (Z4 M40i)
- 12 51 245 Remove and install/replace transmission module engine wiring, (Z4 M40i)
- 12 61 Oil Pressure Switch, Oil Level Sensor
- 12 63 Power Distribution Box
- 12 90 ECM Housing
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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