318 Ho R230 Dual Battery System 11-28-02

R230 Dual Battery On-board Electrical System

318 HO Dual Battery (ACB) 11-28-02

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These technical training materials are current as of the date noted on the materials, and may be revised or updated without notice. Always check for revised or updated information. To help avoid personal injury to you or others, and to avoid damage to the vehicle on which you are working, you must always refer to the latest Mercedes-Benz Technical Publication and follow all pertinent instructions when testing, diagnosing or making repair. Illustrations and descriptions in this training reference are based on preliminary information and may not correspond to the final US version vehicles. Refer to the official introduction manual and WIS when available. Copyright Mercedes-Benz USA, LLC, 2002

Reproduction by any means or by any information storage and retrieval system or translation in whole or part is not permitted without written authorization from Mercedes-Benz USA, LLC or it's successors. Published by Mercedes-Benz USA, LLC Printed in U. S.A.

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Dual Battery System Tasks • Extends vehicle’s driving time for safety Manage electrical power consumption by temporarily disabling convenience consumers if vehicle power falls below a certain voltage.

• Guarantees vehicle will start with a dead systems battery To provide a back-up power supply to the systems circuit if the system battery cannot provide sufficient power to the vehicle.

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Program Highlights • Dual battery on-board electrical system components - starter battery - systems battery - vehicle power supply control module - battery cut-off relay - isolation relay • Power distribution - prefuse diagram - prefuse locations • Dual battery functional description - normal modes - failure modes

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Starter Battery (G1/4)

Note: when jump starting, ONLY USE THIS BATTERY!

• Starter battery: 12V

35Ah

315A (DIN)

520A (EN)

• Construction: standard automotive lead acid (maintenance required) • Function: i) supplies electrical power for starter motor armature only ii) provides back up power to the system circuit

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Starter Battery Failure Display

• Multi-function display red (category 1 malfunction) • DTC’s will be set in the vehicle power supply control module (N82/1) • Cannot be erased by customer (can only be erased using SDS / DAS)

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Systems Battery (G1)

Note: when jump starting, NEVER USE THIS BATTERY!

Location: in trunk - right side ••

Systems Systems battery: battery:

12V 12V

70Ah 70Ah

450A 450A (DIN) (DIN)

798A 798A (EN) (EN)

••

Contruction: Contruction: Valve Valve Regulated Regulated Lead Lead Acid Acid (VRLA) (VRLA) type, type, using using Absorbent Absorbent Glass Glass Mat Mat (AGM) (AGM) design design

••

Function: Function: supplies supplies electrical electrical power power for for entire entire vehicle vehicle (incl. (incl. the the starter starter solenoid) solenoid) with with the the exception exception of of the the starter starter motor motor armature armature 7

AGM / VRLA Battery Construction

The The major major differences differences in in construction construction between between aa AGM AGM battery battery and and standard standard lead lead acid acid automotive automotive battery battery are: are:

•• Completely Completely sealed sealed case case construction construction •• No No liquid liquid electrolyte electrolyte in in solution solution •• Absorbent Absorbent glass glass mat mat (V) (V) holds holds electrolyte electrolyte in in contact contact with with positive positive and and negative negative plates plates •• Vent Vent valve valve is is normally normally sealed sealed no no gases gases can can escape escape during during normal normal charging charging •• Vent Vent valve valve is is only only opened opened ifif internal internal pressure pressure exceeds exceeds predetermined predetermined level level 8

AGM / VRLA Battery Properties •• Longer Longer service service life life •• Improved Improved deep deep cycle cycle performance performance •• No No liquid liquid acid acid spills spills or or leaks leaks •• Fast Fast recharge recharge time time •• Completely Completely maintenance maintenance free free

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AGM / VRLA Battery Testing • AGM batteries cannot be tested using previous methods (load and acid density tests) • Requires the new Midtronics MCR 717 tester and printer • Tester measures battery conductance by inducing A/C voltage of a given frequency and amplitude on the battery posts and monitoring the current flow in response to it • Discard the acid density sheet, and enter test code (recorded by tester) on warranty claim forms • Battery replaced under warranty must have a test printout attached to the R.O. • Detailed information about testing, and using the MCR717 can be found in WIS SI54.10-P-0003-01

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Systems Battery Failure Display

• Multi-function display blue (category 2 malfunction) • DTC’s will be set in N82/1 • High current consumers are shut down (prioritization feature) 11

Prefuse Diagram N10/11

F32 4700µ F

K40/4

E

200 A 80 A 40 A

M4/7

N10/10

2 3

K40/2

4

N73

5

M2

F52

F33

N10/8

60 A

K40/5

200 A

N73 N3/10 N80

f2

f1

7,5 A

100 A

200 A

1

200 A

100 A

K57 30

30a G2

M1

G1

N82/1 G1/4

F32 F33 F52 G1 G1/4

prefuse front prefuse rear prefuse block systems battery starter battery

K40/4 K40/5 K57

fuse and relay module (FR) fuse and relay module (rear) battery cut- off relay

M1 M2 M4/7

starter blower motor engine fan

G2 alternator K40/2 fuse and relay module (FL) N3/10

N10/8 N10/10 N10/11 N73 N80 N82/1

SAM (rear) SAM (FL) SAM (FR) Electronic ignition switch (EIS) Steering column module (SCM) Vehicle power supply control module

engine control module (ME) 12

Front Prefuse Block (F52) Remove Cover

F52f2 200A

F52f1 100A

Location: Location: passenger passenger footwell footwell (upper (upper left) left)

F52f1- Circuit 30a protection for supply wires to K57, K75, and N82/1 F52f2- Alternator (G2) short circuit protection

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Front Prefuse Block (F32)

F32 F52

Location: Location: passenger passenger footwell footwell

Function: over current protection for the following (see next page)

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Front Prefuse Block (F32)

E E -- Power Power input input 11 -- F32f1, F32f1, 100A 100A to to suction suction fan fan (M4/7) (M4/7)

C1

22 -- F32f2, F32f2, 200A 200A to to SAM SAM FR FR (K40/4) (K40/4) 33 -- F32f3, F32f3, 200A 200A to to SAM SAM FL FL (K40/2) (K40/2) 44 -- F32f4, F32f4, 80A 80A to to EIS EIS (N73) (N73) 55 -- F32f5, F32f5, 40A 40A to to HVAC HVAC blower blower (M2) (M2) C1 C1 -- Capacitor Capacitor 4700 4700 µµ ff (Filter) (Filter) 5

4

3

2

1

E

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Rear Prefuse Block (F33) F33 F33 f3 f3 -- External External fuse fuse 7.5A 7.5A Used Used for for Emergency Emergency Engine Engine Stop Stop

3f 3 F

3

•• Feeds Feeds Z4/4 Z4/4 (30z) (30z) -- EIS EIS (N73) (N73) power power supply supply -- SCM SCM (N80) (N80) power power supply supply -- ME ME (N3/10) (N3/10) power power supply supply Location: Location: right right side side of of trunk trunk Note: Note: vehicle vehicle fuse fuse chart chart refers refers to to this this fuse fuse as as #78 #78 16

Internal Fuses (F33)

f1 3 3 F

-

0/4 4 K

Feed to 7.5A fuse

F33f2 - K40/5

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Vehicle Power Supply Control Module (N82/1) N8 2/1

Front

Location: Location: right right side side of of trunk trunk Note: Note: SDS SDS // DAS DAS Acronym Acronym BNS BNS (Board (Board Net Net System) System) 18

N82/1 Function as Described in WIS 1. Monitors the voltages of (G1) and (G1/4) 2. Controls battery cut-off relay (K57) 3. Protects vehicle electrical systems from voltage surges 4. Protects vehicle electrical systems from short circuits 5. Controls consumer prioritization function 6. Optimizes charging of starter battery (G1/4) 7. Notes emergency operation and sets fault codes (CAN communication / DTC’s) 19

Cut-off (K57) and Isolation (K75) Relays

K57 K 75

Location: Location: right right side side of of trunk trunk 20

Function of Relays (K57) and (K75) Cut-off relay (K57): •• Controlled Controlled by by N82/1 N82/1

K57

•• De-energized De-energized during during normal normal operation operation (N.O.) (N.O.) -- Isolates Isolates (G1) (G1) from from (G1/4) (G1/4) during during normal normal operation operation •• Energized Energized during during emergency emergency operation operation -- Connects Connects (G1/4) (G1/4) to to (G1) (G1) during during emergency emergency operation operation

Isolation relay (K75): K75

•• Controlled Controlled by by N82/1 N82/1 •• De-energized De-energized during during normal normal operation operation (N.C.) (N.C.) •• Energized Energized during during emergency emergency operation operation -- Opens Opens 30/15R 30/15R to to cigar cigar lighter lighter (R3r1), (R3r1), and and 12V 12V trunk trunk socket socket (X58/1) (X58/1) during during emergency emergency operation operation 21

Dual Battery On-board Electrical System Functional Description

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CAN Communication N82/1

(FL)

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Dual Battery Circuit Diagram Starter Battery Circuit

Systems Battery Circuit K57

F52f1

M1

G1/4

. 30a

DC/DC Converter

F52f2

30

200

100

N73 Load 1

31

G1

C1

Load 2 Load G2

CAN-B

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Normal Operation (Wake-up) Starter Battery Circuit

Systems Battery Circuit K57

F52f1

M1

G1/4

. 30a

DC/DC Converter

F52f2

30

200

100

N73 Load 1

31

G1

C1

2 Load G2

CAN-B

N82/1 control module is activated by: CAN-B or microswitch in EIS 25

Normal Operation (Voltage Monitoring) Starter Battery Circuit

Systems Battery Circuit K57

>10.8V

>10.8V F52f1 100

G1/4

DC/DC Converter

F52f2

30

200

M1

. 30a

N73 Load 1

31

G1

C1

2 Load G2

CAN-B

N82/1 control module checks battery voltages 26

Normal Operation Starter Battery Circuit

Systems Battery Circuit K57

>10.8V

>10.8V F52f1 100

G1/4

DC/DC Converter

F52f2

30

200

M1

. 30a

N73 Load 1

31

G1

C1

2 Load G2

CAN-B

N82/1 control module isolates starter battery from systems battery via open relay K57 (not energized) 27

Normal Operation (Charging) Systems Battery Circuit

Starter Battery Circuit K57

F52f1 100

G1/4

DC/DC Converter

30

F52f2 200

M1

. 30a

N73 Load 1

31

G1

C1

2 Load G2

CAN-B

• Engine running, alternator charges the systems battery directly • Starter battery charged via the DC / DC converter (15A max), based on: - Starter battery voltage - Starter battery temperature calculated by N82/1 using: - Ambient temperature (B14) - Engine coolant temperature (B11/4)

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Emergency Start (Wake-up) Systems Battery Circuit

Starter Battery Circuit K57

F52f1 100

G1/4

DC/DC Converter

F52f2

30

200

M1

. 30a

N73 Load 1

31

G1

C1

2 Load G2

CAN-B

Scenario - Systems battery weak: N82/1 control module is activated by the ground microswitch in EIS (N73) 29

Emergency Start (Voltage Monitoring) Systems Battery Circuit

Starter Battery Circuit K57

<10.8V

>10.8V F52f1

M1

G1/4

DC/DC Converter

F52f2

30

200

100

. 30a

N73 Load 1

31

G1

C1

2 Load G2

CAN-B

• N82/1 control module checks battery voltages (for up to 30 seconds) • Terminal 30 less than 10.8 volts • N82/1 control module initiates emergency start operation 30

Emergency Start Starter Battery Circuit

F52f1 100

G1/4

K57

. 30a

DC/DC Converter

F52f2

30

200

M1

Systems Battery Circuit

N73 Load 1

31

G1

C1

2 G2

Load

CAN-B

• N82/1 activates relay (K57), starter battery supplies power to systems circuit • N82/1 control module sends emergency operation message via CAN B • DTC‘s stored in N82/1 31

Emergency Operation (Limp Home) Starter Battery Circuit

F52f1 100

G1/4

K57

. 30a

DC/DC Converter

F52f2

30

200

M1

Systems Battery Circuit

N73 Load 1

31

G1

C1

2 G2

Load

CAN-B

• Engine running alternator charges G1 and G1/4 • Relay (K57) remains activated ~5 minutes after engine is started to quick charge G1/4 • Prioritization function active for ~8 to 18 minutes (if voltage at t30 > ~10.8V) 32

Ending / Switch Off Phase Starter Battery Circuit

F52f1 100

G1/4

K57

. 30a

DC/DC Converter

F52f2

30

200

M1

Systems Battery Circuit

N73 Load 1

31

G1

C1

2 G2

Load

CAN-B

• Engine off after an emergency start • Cut-off relay (K57) re-activates for ~5 minutes after engine is switched off 33

Emergency Mode Summary • N82/1 activates cut-off relay (K57) and isolation relay (K75) • Starter battery (G1/4) supplies power to systems circuit • N82/1 sends emergency operation message via CAN B • N82/1 stores DTC‘s • Instrument cluster multi-function display “Electric consumers offline!“ • Prioritization function active: - seat heaters inoperative - seat fans inoperative - Vario roof can only be raised - AAC blower is regulated up to a maximum of 50% - rear window defroster inoperative - parktronic switched off - radio volume limited 34

Emergency Mode Summary (cont.) • Engine switched off, SmartKey in pos. 0 or removed: - K57 remains energized for ~5 min. (e.g. windows, CTEL, or TeleAid call) • SmartKey reinserted in pos. 0: - K57 will re-energize for 30 seconds

• SmartKey reinserted to pos. 1 or 2: - K57 will re-energize for ~5 min. • If voltage at N82/1 terminal 30 increases to >10.8v: - prioritization function cancelled after ~8 to 18 min. of engine running

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Dual Battery Service Tips Normalization: IfIf batteries batteries are are disconnected disconnected or or dead, dead, the the following following systems systems should should be be checked checked for for normal normal operation. operation. IfIf systems systems are are inoperative inoperative or or erratic erratic then then normalization normalization will will have have to to be be performed. performed. Potential Potential systems systems requiring requiring normalizing normalizing are: are:

• ESP - electronic stability program • AAC - automatic air conditioning (2 items) • Left front seat (7 items) • Right front seat (7 items) • Steering wheel and mirrors • Windows • Tire pressure monitoring 36

Dual Battery Service Tips • When reconnecting batteries you must follow an appropriate sequence to avoid setting fault codes and / or activating prioritization feature - Key removed from EIS - Connect starter battery (G1/4) - FIRST - Connect systems battery (G1) - LAST • Charging batteries may not be possible if < 7 volts. Follow procedure for using parallel battery method of charging

(WIS AF 54.10-P-6005A)

• To start a Keyless Go equipped vehicle with a dead systems battery (G1) when using only the KG chip card: - Activate N82/1 ground contact by opening the EIS door - Start vehicle as normal 37

Appendix WIS doc.#

Topic

AR51.10-P-1129-01A

Checking battery with Midtronics MCR717

OF58.40-P-3000-04A

Order form for Midtronics MCR717

GF54.10-P-6005A

Problems with charging batteries

GF54.10-P-4200R

Battery cut-off relay, location, and function

GF54.10-P-1001R

Two-battery vehicle power supply, function

GF54.21-P-4118R

Vehicle power supply control module, function

GF54.21-P-4118-01R

Vehicle power supply control module, task

PE54.10-U-2101-99KA

Wiring diagram of N82/1

Internet Site www.midtronics.com

Topic Total battery management (AGM) charging, testing 38

Legend

Load Load 11 Load Load 22 C1 C1 F32 F32 F33 F33 F52 F52 F52f1 F52f1 F52f2 F52f2 G1 G1 G1/4 G1/4 G2 G2 K40/2 K40/2 K40/4 K40/4

Consumers Consumers Consumers Consumers F32, F32, 4700 4700 µµ ff capacitor capacitor Prefuse Prefuse block block front front Prefuse Prefuse block block rear rear Prefuse Prefuse block block through through panel panel Fuse Fuse panel panel 100A 100A Fuse Fuse panel panel 200A 200A Systems Systems battery battery Starter Starter battery battery Alternator Alternator Fuse Fuse and and relay relay module module (FL) (FL) Fuse Fuse and and relay relay module module (FR) (FR)

K40/5 K40/5 K57 K57 K75 K75 N10/8 N10/8 N10/10 N10/10 N10/11 N10/11 N73 N73 N80 N80 N82/1 N82/1 M1 M1 M2 M2

Rear Rear fuse fuse and and relay relay module module Battery Battery cut-off cut-off relay relay Circuit Circuit 15R 15R // 30 30 cut-off cut-off relay relay SAM SAM (rear) (rear) SAM SAM (FL) (FL) SAM SAM (FR) (FR) Electronic Electronic ignition ignition switch switch Steering Steering column column module module (SCM) (SCM) Vehicle Vehicle power power supply supply control control module module Starter Starter HVAC HVAC blower blower

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