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.
2018 BMW 740iFACTORY OEM SERVICE PROCEDURE
General Electrical System -- Repair (G12) (1 Of 2)
- 61 00 General Information
- Information on removing, connecting and changing the battery (all 7' series models 2016-2022)
- Notes for disconnecting and connecting the vehicle battery (all 7' series models 2016-2022)
- Notes on handling optical fibers (all 7' series models 2016-2022)
- Notes on handling the high pressure cleaner (all 7' series models 2016-2022)
- Notes on handling wiring harnesses and cables (all 7' series models 2016-2022)
- Parking-residing-driving (all 7' series models 2016-2022)
- Repairing airbag cables (all 7' series models 2016-2022)
- Safety instructions for handling vehicle battery (all 7' series models 2016-2022)
- Safety instructions on handling hybrid cars (all 7' series models 2016-2022)
- 61 00 730 Programming/encoding the control unit (s) including deletion of fault memory (after vehicle test) (all 7' series models 2016-2022)
- 61 12 Battery Ground Cable (12V), Plug-In HEV Wiring Harness, Plug-In HEV Charging Socket
- Notes on intelligent battery sensor (IBS) (all 7' series models 2016-2022)
- 61 12 013 Replacing the battery ground lead (740i 2016-2022, 740i xDrive 2017-2022, 750i 2016-2019, 750i xDrive 2016-2022, M760i xDrive 2017-2022)
- 61 12 013 Replacing the battery ground lead (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 12 460 Remove and install/replace high-voltage charging socket (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 12 472 Removing and installing/replacing the high-voltage wiring harness for KLE - EME (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- Removing high-voltage connection for electrical machine (vehicle underbody)
- Removing the high-voltage connection for electrical machine
- Detaching cable bracket
- Tightening cable bracket
- Installing high-voltage connection for the electrical machine
- Installing high-voltage connection for the electrical machine (vehicle underbody)
- 61 13 Electrical Connectors
- Butt connector for repairing a plug connection (all 7' series models 2016-2022)
- Circular connector, 13-pin, system D2.5 (all 7' series models 2016-2022)
- Connector housing, LCC contact (load current contact) (all 7' series models 2016-2022)
- Crimping Micro Power Quadlock contacts (MPQ) (all 7' series models 2016-2022)
- Crimping annular contacts (all 7' series models 2016-2022)
- Crimping of Nano MQS contacts (MQS) (all 7' series models 2016-2022)
- Crimping Micro Quadlock System contacts (MQS) (all 7' series models 2016-2022)
- Cutting, strip off insulation and crimping optical fibers (all 7' series models 2016-2022)
- Cutting to length and strip off insulation from cables (all 7' series models 2016-2022)
- In-line connectors, 24-/44-pin, Hybrid System MQS/MPQ (all 7' series models 2016-2022)
- Inline connectors, 6-, 8-pin, System MQS (all 7' series models 2016-2022)
- In-line plugs, 2-pin, System MDK 3 plus 2.8 (all 7' series models 2016-2022)
- Inline plugs, 2-pin, System MPQ 2.8 (all 7' series models 2016-2022)
- Inline plugs, 3-, 6-pin, System Elo-Power 2.8 (all 7' series models 2016-2022)
- Inline plugs, 4-, 10-pin, System Elo (all 7' series models 2016-2022)
- Socket housing (radio connector), Hybrid System MQS/MPQ (all 7' series models 2016-2022)
- Socket housing 42-, 43-, 46-pin, Hybrid System MQS/MPQ (all 7' series models 2016-2022)
- Socket housings, 2x21-, 2x27-pin, Hybrid Systems MQS/MPQ, Elo/Elo Power (all 7' series models 2016-2022)
- Socket housings, 5-pin, 8-pin, System MQS/MPQ (all 7' series models 2016-2022)
- Special tools for wiring harness repairs (all 7' series models 2016-2022)
- Unlocking and disconnecting various plug connections in electrical and hybrid vehicles (all 7' series models 2016-2022)
- Unlocking and disconnecting different plug connections (all 7' series models 2016-2022)
- 61 13 250 Removing and installing separator for integral active steering (all 7' series models 2016-2022)
- 61 14 Power Distribution Box
- 61 14 010 Remove and install/replace power distribution box (trunk) (all 7' series models 2016-2022)
- 61 14 040 Removing and installing/replacing rear power distribution box positive battery cable (all 7' series models 2016-2022)
- 61 14 041 Removing and installing/replacing rear power distribution box positive battery cable (behind luggage compartment trim panel, right) (all 7' series models 2016-2022)
- 61 14 035 Removal & install/replace power distribution box front positive battery cable (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 20 Battery, General Information
- Notes on AGM battery (all 7' series models 2016-2022)
- Vehicle battery - closed current monitoring (all 7' series models 2016-2022)
- 61 20 900 Disconnecting and connecting battery ground lead (All negative battery cables) (740i 2016-2022, 740i xDrive 2017-2022, 750i 2016-2019, 750i xDrive 2016-2022, M760i xDrive 2017-2022)
- Remove right windshield panel cover
- Disconnecting the negative battery cable of the auxiliary battery in the engine compartment
- Disconnecting the negative battery cable of the 12-V lithium-ion auxiliary battery
- Removing the luggage compartment floor covering
- Disconnect the battery earth lead for the active steering
- Disconnecting the negative battery cable of the system battery
- Connecting negative battery cable of the system battery
- Connect the battery earth lead for the active steering
- Installing the luggage compartment floor covering
- Connecting the negative battery cable of the 12-V lithium-ion auxiliary battery
- Connecting the negative battery cable of the auxiliary battery in the engine compartment
- Install the right windshield panel cover
- Activating the 48 V electrical system
- 61 20 908 Running vehicle battery "power reset" (all 7' series models 2016-2022)
- 61 20 900 Disconnecting and connecting battery ground lead (All negative battery cables) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- Remove flap in luggage compartment trim panel on right
- De-energize the high-voltage system
- Check that no voltage is applied
- Disconnecting the negative battery cable (starter unit battery)
- Remove the rear luggage compartment floor covering
- Disconnecting the negative battery cable of the system battery
- Disconnect the battery earth lead for the active steering
- Connect the battery earth lead for the active steering
- Connecting negative battery cable of the system battery
- Install the rear luggage compartment floor covering
- Connecting the negative battery cable (12 V battery)
- Activate high-voltage system
- Install flap in right luggage compartment trim panel
- 61 21 Battery (12V And 48V)
- 61 21 003 Removing and installing the 12V dual storage system (all 7' series models 2016-2022)
- 61 21 004 Replacing the 12V dual storage system - registering with battery change - (all 7' series models 2016-2022)
- 61 21 006 Removing and installing 48 V battery (with holder) (740i 2016-2022, 740i xDrive 2017-2022, 745e xDrive PHEV 2020-2022)
- 61 21 007 Replacing 48-V battery - with registering battery replacement - (740i 2016-2022, 740i xDrive 2017-2022, 745e xDrive PHEV 2020-2022)
- 61 21 008 Removing and installing the vehicle battery (Auxiliary battery) (vehicle with integral active steering) (740i 2016-2022, 740i xDrive 2017-2022, 750i 2016-2019, 750i xDrive 2016-2022, M760i xDrive 2017-2022)
- 61 21 010 Removing and installing the vehicle battery (740i 2016-2022, 740i xDrive 2017-2022, 750i 2016-2019, 750i xDrive 2016-2022, M760i xDrive 2017-2022)
- 61 21 017 Replacing vehicle battery - registering with battery replacement - (740i 2016-2022, 740i xDrive 2017-2022, 750i 2016-2019, 750i xDrive 2016-2022, M760i xDrive 2017-2022)
- 61 21 028 Charging battery (all 7' series models 2016-2022)
- Charging parameters for lithium ion batteries (all 7' series models 2016-2022)
- Description of the manual Li parameter setting for DEUTRONIC DBL800/1200/1600 (all 7' series models 2016-2022)
- Description of the manual Li parameter setting for ELEKTRON HS-1000 (all 7' series models 2016-2022)
- Description of the manual Li parameter setting for ELTEK MultiCharger 750/900/1500 (all 7' series models 2016-2022)
- 61 21 028 Supporting voltage of the vehicle electrical system/recharging vehicle battery (all 7' series models 2016-2022)
- 61 21 065 Removing and installing vehicle electrical system support battery (740i 2016-2022, 740i xDrive 2017-2022, 750i 2016-2019, 750i xDrive 2016-2022, M760i xDrive 2017-2022)
- 61 21 085 Removing and installing 12 V lithium ion auxiliary battery (all 7' series models 2016-2022)
- 61 21 086 Change 12-V lithium-ion auxiliary battery - register with battery replacement - (all 7' series models 2016-2022)
- 61 21 006 Removing and installing 48 V battery (with holder) (740e xDrive PHEV 2017-2019)
- 61 21 007 Replacing 48-V battery - with registering battery replacement (740e xDrive PHEV 2017-2019)
- 61 21 010 Removing and installing the vehicle battery (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 21 017 Replacing vehicle battery - registering with battery replacement - (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 25 High-Voltage Battery System
- Assessment of the transportability of lithium-ion starter/auxiliary batteries in service workshops (all 7' series models 2016-2022)
- Assessment of the transport condition of super capacitor storage devices in service workshops (all 7' series models 2016-2022)
- Notes on repair of high-voltage battery unit (all 7' series models 2016-2022)
- 61 25 010 Removing and installing high-voltage battery unit (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 25 900 De-energize the high-voltage system (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 500 Replace the cover for the high-voltage battery unit (high-voltage battery unit removed) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 501 Removing and installing lid for high-voltage battery unit (high-voltage battery unit removed) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 521 Replacing venting unit (high-voltage battery unit removed) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 531 Replacing high-voltage connection (high-voltage battery unit removed) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 551 Replace safety box (after vehicle diagnosis) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 566 Replacing the communication vehicle wiring harness (high-voltage battery unit removed) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 571 Replacing battery management electronics (SME) (After vehicle diagnosis) (high voltage battery unit removed) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 581 Replace the housing pan for the high-voltage battery unit (high-voltage battery unit removed) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 591 Replacing high voltage connecting wire (high-voltage battery unit removed) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 596 Replacing radiator for high-voltage battery unit (high-voltage battery unit removed) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 598 Replace radiator for high-voltage battery unit at the bottom (high-voltage battery unit removed) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 630 Removing and installing all cell modules (High-voltage battery unit removed) (lid of high-voltage battery unit removed) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- Removing cell module 3
- Removing cell module 4
- Removing cell module 6
- Removing the radiator, top
- Removing cell module 1
- Removing cell module 2
- Removing cell module 5
- Installing cell module 5
- Installing cell module 2
- Installing cell module 1
- Installing top radiator
- Installing cell module 6
- Installing top radiator/t>
- Installing cell module 4
- Installing cell module 3
- 61 27 650 Set up high-voltage battery unit for replacement (After vehicle diagnosis) (high voltage battery unit removed) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- Install venting unit
- Installing the holders for the high-voltage cables
- Install high-voltage connection
- Install high-voltage connecting line
- Installing the positioning pin
- Install bottom radiator
- Installing cell module 1
- Installing cell module 2
- Installing cell module 6
- Installing cell module 5
- Installing communication wiring harness
- Installing the top removable panel
- Installing top radiator
- Installing cell module 3
- Tighten radiator
- Installing cell module 4
- Installing the distributor block
- Installing the battery management electronics (SME) including holder
- Installing the safety box including holder
- Installing the lid of the high-voltage battery unit
- Installing the holder
- 61 27 671 Replacing the distributor block for the high-voltage battery unit (high-voltage battery unit removed) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 677 Replacing the radiator connecting flange (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 711 Replacing cell module 1 (high-voltage battery unit removed) (lid for high-voltage battery unit removed) (after vehicle diagnosis) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 713 Replacing cell module 2 (High voltage battery unit removed) (lid of high-voltage battery unit removed) (after vehicle diagnosis) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 717 Replacing cell module 4 (High voltage battery unit removed) (lid of high-voltage battery unit removed) (after vehicle diagnosis) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 719 Replacing cell module 5 (High voltage battery unit removed) (lid of high-voltage battery unit removed) (after vehicle diagnosis) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 721 Replacing cell module 6 (High voltage battery unit removed) (lid of high-voltage battery unit removed) (after vehicle diagnosis) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 761 Replacing CSC, 1 (High voltage battery unit removed) (lid of high-voltage battery unit removed) (after vehicle diagnosis) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 763 Replacing CSC, 2 (High voltage battery unit removed) (lid of high-voltage battery unit removed) (after vehicle diagnosis) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 765 Replacing CSC, 3 (High voltage battery unit removed) (lid of high-voltage battery unit removed) (after vehicle diagnosis) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 767 Replacing CSC, 4 (High voltage battery unit removed) (lid of high-voltage battery unit removed) (after vehicle diagnosis) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 769 Replacing CSC, 5 (High-voltage battery unit removed) (Lid of high-voltage battery unit removed) (after vehicle diagnosis) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 771 Replacing CSC, 6 (High voltage battery unit removed) (lid of high-voltage battery unit removed) (after vehicle diagnosis) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
- 61 27 910 Repair of temperature sensor (negative temperature coefficient) on a cell module (cell module removed) (740e xDrive PHEV 2017-2019, 745e xDrive PHEV 2020-2022)
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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