8/6/2019 190E

1/48

lectrical system,

EXIT

8/6/2019 190E

2/48

Job No.

Notes regarding jobs on breakerless transistorized ignition system ................... 15 - 505Function of the electronic ignition system with variable characteristics (EZL) ............. - 510Checking ignition timing .................................................. - 515Evaluation of oscilloscope image ........................................... - 525Renewing spark plugs ................................................... - 530Removal and installation of high - voltage distributor ............................. - 535Checking the electronic ignition system with variable characteristics (EZL) .............. - 545

EXIT

8/6/2019 190E

3/48

15505 Notes regarding Jobs m breakerless transistorised ignition system

A. Safety information

Increased demands of modern engines onignition systems and the desire for maintenance-free operation have resulted in the use of series-produced electronic ignition systems.

As a rule, the firing output of electronic systemsis superior to that of conventional systems: still

further output improvements may be anticipated.As a result, electronic ignition systems enter anoutput range where the contact with live parts orterminals maybe lethal (see warning plate).

Geftihrliche Wochspannung!Vorsicht bei Arbeiten an derZiindanlage

Danger! High voltageObserve caution when workingon the ignition system

Danger! Haute tensionAttention lors de travaux ausysteme dallumage

Warning plate in the engine compartment

For this reason it is absolutely vital to observethe following safety regulations when working onthe breakerless transistorized ignition system:

0 Prior to working at starter speed, e.g. whenchecking the compression or adjusting thevalve clearance, switch off the ignition andpull off control cable from control unit (arrow)or fit protective plug, part no. 102 589 02 2100, on the diagnostic socket.

Persons with heart pace-makers should notwork on these ignition systems.

Do not touch and pull off any of the ignitionsystem components at starting rpm or withthe engine running.

1 5 . 1 1 I I - 5 0 5 / l

EXIT

8/6/2019 190E

4/48

l Perform assembly jobs on the ignitionsystem or connect and disconnecttransmitters to ignition cables only with theengine stopped and the ignition switched off.

l Do not install any intermediate pieces with abright metallic finish or any such transmittersinto ignition cables, e.g. cylinder 1.

. Notes for avoiding damage to ignition system

In order to avoid damage to the controlunit, only remove and fit the control unitplugs with the ignition switched off.

Do not connect any test lamp to terminal 1of the ignition coil.

Do not short-circuit terminals 1 and 15 of theignition coil to ground, e.g. for burglar alarmprovision.

In order to avoid wrong polarity connections,the threaded pins of the ignition coil havedifferent diameters (M5 and M6).

Install only genuine ignition systemcomponents.

Do not operate the ignition system at startingspeed without fully connected ignition gear.

In order to avoid damage to the control unit,the high-tension side of the ignition systemmust be loaded with at least 2 kR (distributorrotor 1 kQ, distributor cap 1 kQ perconnection). Do not install 5 k0 distributorrotors for interference suppression.

1 5 . 1 1 I I - 5 0 5 / 2

EXIT

8/6/2019 190E

5/48

l At starting speed or with running motor, donot carry out tests such as holding ignitioncable 4 with a distance against ground,pulling a spark plug connector or cable 4from the ignition coil.

l For better heat dissipation, the control unit ismounted with heat conductive paste to theinner wing.During replacement, do not remove theprotective foil as it does not impair the heatdissipation.

l If the short-circuit device (comparison ofcylinders) is actuated and the engine stops,the test cannot be carried out with this

tester.

l During the separate ignition coil test, do notload the ignition coil with more than 28 kV inorder to avoid damage to the ignition coil.

l If checking the ignition spark becomesnecessary during a breakdown, this may onlybe carried out by means of a spark plugconnected to a cylinder ignition cable.Ensure proper ground contact of the sparkplug. Danger, risk of electrocution!

C. Motes for the use of testers and measuring devices

l Connect and disconnect voltage transmitterpliers to cable 4 and trigger pliers to cylinder1 only with the engine stopped and theignition switched off.

1 5 . 1 1 I I - sow3

EXIT

8/6/2019 190E

6/48

15-510 Function of the electronic ignitiori system with variablecharacteristics (

Function diagram electronic ignition system with variable characteristics (EZL)

61 l/2GIL5Nll2R 4

R16s5/3

s29/2Tlx111

2

Temperature sensor, coolant (EZUCIS-E/2E-E)BatteryPosition pickup, crankshaftControl unit transistorized ignition system (EZL)Spark plugsReference resistor plug (EZL)High voltage distributor

Throttle valve switch, full load/idle speed detectionlgnitron co11Oiagnostlc socket/cable connector, terminal TDSegments on flywheel/driven plateVacuum pipe

15.11 II - 510/l

EXIT

8/6/2019 190E

7/48

Arrangement of components

1

3 16

1 1 5 3 - 1 5 8 2 1

I31 l/2 Temperature sensor, coolant (EZUCIS-EME-E)L5 Position pickup, crankshaftN1/2 Control unit transistonzed ignition system (EZL)RI6 Reference resistor plug (EZL)s513 High voltage distnbutorS29/2 Throttle valve switch, full load/idle speed detectionT l Ignition coil

1 5 . 1 1 II 5 1 0 / 2

EXIT

8/6/2019 190E

8/48

Model survey

r-Engine I Model I Version

0US A

I 103.943 I 124.226 II103.981 I 126.0241025 I OUS A

I103.985 I 124.2301290 I

outputkW

118

132

Compression&

1 5 . 1 1 I I - 5 1 0 1 3

EXIT

8/6/2019 190E

9/48

Components and function

Control unit (N1/2)

Ignition coil

terminal 1

Poweroutputstage withprimarycurrent

limitation

Microcomputer

II

IIIIII

II

I

IIIII

III

I

I

IIIII

I

+

TD signal Ground Positive

___-_.

I

I

I

I

II

I

I

I

I

I

I

I

I

I

--_A

1 5 . 1 1 I I - 5 1 0 / 4

EXIT

8/6/2019 190E

10/48

The ignition control unit is arranged on the leftinner wing.

For improved heat dissipation it is installed withheat conducting paste. During replacement, donot remove the protective foil. The foil does notimpair the heat dissipation. The control unit isequipped with a microcomputer, a pressuresensor and the power output stage.

1 Va c u u m connectlon 4 Plug - 4-pole supply2 Coaxial plug for control 15 = Terminal 1 5

cable from position 1 6 = Ignition ~011,pickup terminal 1

3 Plug - 4-pole pickup TD = TD signal1 temperature sensor, 3 1 = Groundcoolant2 Throttle valve switch3 EZL reference resistor plug4 vacant (cable ends In cable harness)

The characteristics for typical load/speed rangesand a fixed idle speed ignition characteristic are

stored in the microcomputer of the control unit.

By means of various input signals, the controlunit recognises the current operating condition ofthe engine. Engine speed and crankshaftposition are picked up by the position pickup.

Considering all input signals, the storedcharacteristics are used to arrive at the optimumignition timing for the respective operatingcondition,

The power output stage triggered bymicrocomputer controls the primary current ofthe ignition coil between terminals 16 and 31 (4-pole plug, supply).

1 5 . 1 1 II - 5 1 0 1 5

EXIT

8/6/2019 190E

11/48

The control unit also incorporates the knownfunctions dwell angle control, primary currentcutoff and primary current limitation.

The speed-dependent TD-signal is generated inthe ignition control unit.

When starting the engine up to approximately450/min, the ignition timing is controlled only viathe segment edges of the flywheel. Only whenreaching a certain speed (approximately460/min), the control unit no longer uses thefixed ignition timing, but the timing calculatedfrom the current operating conditions.

During the warming-up phase, various ignition

characteristics are blocked depending on thecoolant temperature in order to reach theoperating temperature as quickly as possible.

At idle speed and during deceleration, a fixedcharacteristic is used while the idle speedcontact of the throttle valve switch is closed.This characteristic is neither influenced by thetemperature sensor, the intake manifold vacuumnor the EZ L reference resistor plug.

NoteIn the case of coolant temperature sensorinterruption (resistance a%2), the fixedcharacteristic on Bosch ignition control units isno longer used and a certain ignition timing inthe family of characteristics is selected, i.e. theignition timing is advanced.

At full load the ignition timing is determined bythe full load characteristic. Under consideration

of the octane requirement the ignition timing isadvanced at this stage (higher engine torque).

1 5 . 1 1 I I - 5 1 0 1 6

EXIT

8/6/2019 190E

12/48

Full load condition is recognised by the ignitioncontrol unit from the input signals intake manifoldvacuum and engine speed.

When exceeding a coolant temperature ofapproximately 95 C , certain ignitioncharacteristics are retarded in order tocounteract further temperature rise.

Depending on the operating condition, theignition timing of certain ignition characteristicscan be adjusted by means of the EZ L referenceresistor plugs.

Position pickup (L5)The position pickup registers the crankshaftposition and the engine speed and signals thisinformation to the ignition control unit.

The position pickup is mounted to the crankcaseabove the starter flange (arrow).

The coil body projects to just before thesegments on the flywheel/driven plate. Thesegment position and speed is picked up withoutbeing in contact.

With the engine turning, due to induction analternating voltage is generated in the position

pickup. The peak value of the voltage (U,) isapproximately 1.5 Volt at starting speed. Thevoltage rises with increasing speed (U , approx. 3Volt at 1200/min).

NoteMeasure peak voltage (U,) with the oscilloscope.

0115- 28405

1 5 . 1 1 I I - 5 1 o n

EXIT

8/6/2019 190E

13/48

The crankshaft position is recognised from thevoltage as follows:

The segment front edge generates a negativevoltage signal.

The segment rear edge generates a positivevoltage signal.

1 1 5 4 - 1 4 4 0 6

t l First segmentt2 Second segmentt3 Third segmentd Per& for one crankshaft rotation

The engine speed is determined by measuringthe period.

The alternating voltage from the position pickupis directed to terminal 7 on the ignition controlunit via the control cable (coaxial cable). Thecable is of the single-conductor type. The shieldis used as second conductor.

If the ignition control unit does not receive asignal from the position pickup, the entire ignitionsystem does not function, e.g. this can be

caused by an interruption of the pickup coil.

The resistance of the position pickup is 680-120052.

SegmentsThree segments (arrows) staggered by 120 areprovided on flywheel/driven plate.

A Dnven plate with ring gear(automatlc transmisston)

B Flywheel (manual transmlsslon)

0 1 1 5 - 2 9 1 8 4

1 5 . 1 1 I I - 5 1 0 / 8

EXIT

8/6/2019 190E

14/48

Indications of damaged segments or mechanicaldamage to the position pickup:

l Alternating voltage from position pickupbelow nominal value.

l Alternating voltage signals of the individualsegments differ greatly.

l No alternating voltage signal.

Temperature sensor, coolant (Bl l/2)The temperature sensor coolant has two NTCwith a one-pole connector each. One NTC for

CIS-E and one NTC for EZL.The temperature signal reaches the EZL ignitioncontrol unit via the green/black cable and the 4-pole plug-pickup (jack 1). The temperaturesensor coolant is arranged on the cylinder headrear left.

NoteNTC = negative temperature coefficientthermostat, i.e. the resistance is smaller in thehot state.

Throttle valve switch (S29/2)The fixed idle speed/deceleration characteristic isactivated with closed idle speed contact in thethrottle valve switch (accelerator not depressed).The control signal reaches the ignition control

unit via the 4-pole plug-transmitter (jack 2).

Plug assignment on the plug1 Idle speed contact2 Ground3 Full load contact

0115 - 2 9 2 8 8

1 5 . 1 1 II - 510/g

EXIT

8/6/2019 190E

15/48

EZL individual reference resistor plug (RX/l)The EZL individual reference resistor plug@1 6 / l ) is provided with a fixed resistance.Depending on the national versions, the fixedresistances differ as follows:

Part No. Resistance Nationalv e r s i o n

0 0 0 5 4 0 2 1 8 0 OR @

0 0 0 5 4 0 2 2 8 1 2 2 0 s z 0US0 0 0 5 4 0 2 4 8 1 7 5 0 Q a @

A certain family of characteristics is activated inthe ignition control unit by means of the EZLindividual reference resistor plug ( R 1 6 / 1 )

Resistance measurement to check the individualreference resistor plug ( R 1 6 / 1 )o n the ignitioncontrol unit between plug-pickup (jack 3) andground.

High-voltage distributor (SY3)The high-voltage distributor only has the duty ofdistributing the ignition voltage, an adjustment ofthe ignition timing is no longer possible.

The high-voltage distributor is attached to thefront cylinder head cover and is driven directlyby the camshaft via the driver (5).

The distributor rotor is attached to the driver bymeans of three screws.Interference suppression resistors: on thedistributor cap for each connection 1 kQ, sparkplug connector 1 kQ, distributor rotor 1 kR.

1 5 . 1 1 I I - 5 1 0 / 1 0

EXIT

8/6/2019 190E

16/48

To protect against moisture and dirt, the high-voltage distributor is provided with a cover.

The shielding cover (6) for the long-distanceintereference suppression is secured to thedistributor cap by means of the three socket

head screws.

0115 - 2 8 9 7 5

Ignition coil (Tl)

In order to achieve higher ignition energy, theignition coil has been adapted to the ignitioncontrol unit. The high control output of thecontrol unit permits further increase of theprimary current. For this purpose the primarywinding is designed with a very low resistance(0.3-0.6 Q). Open-circuit current cutoff andprimary current limitation allow ignition coiloperation without pre-resistor.Consequently the current limitation with the pre-resistor is no longer required. If the maximium

primary current flows unlimited in the ignition coil(e.g. open-circuit current cutoff defective), theignition coil will be damaged after a short timedue to overheating.

1 5 . 1 1 I I - 5 1 0 / 1 1

EXIT

8/6/2019 190E

17/48

For identification:For 4 - and 6-cylinder engines with electronicignition systems with variable characteristics(EZL) the ignition coils are identical.Identification: yellow nameplate.The ignition coils are not interchangeable withthe ignition coils for 8-cylinder engines(identification: green nameplate). Observe partnumber when replacing.

Observe notes regarding jobs on electronicignition systems ( 1 5 5 0 5 ) .

1 5 . 1 1 I I - 5 1 0 / 1 2

EXIT

8/6/2019 190E

18/48

8/6/2019 190E

19/48

Arrangement of EZL reference resistor plug

individual reference resistor plug (R16A )

Model 124The EZL individual reference resistor plug isarranged on the left in the accessoriescompartment near the brake assembly.

Model 126The EZL individual reference resistor plug isconnected to the cable harness between thefuse and relay box and the brake assembly.

0 1 1 5 - 3 1 6 2 2

1 5 . 1 1 I I - 5 1 5 / 2

EXIT

8/6/2019 190E

20/48

Model 201The EZL individual reference resistor plug isconnected to the engine cable harness in thevicinity of the starting valve.

1 5 . 1 1 I I - 5 1 5 1 3

EXIT

8/6/2019 190E

21/48

Go-image - parade pattern (engine speeds up to approx. 1OOWmin)

Bias voltage line

Ignition characteristic

- O p e n i n g 0

e

1 1 5 2 -11720

Image selection - Parade pattern. Display image is elongated in horizontal direction.

15.11 II - 525/l

EXIT

8/6/2019 190E

22/48

Go-image - superimposed pattern (engine speeds up to approx. OOO/min)

U(kV)1 0 -

5-

45O 400 35 30 25 20 159 10 5 8 cyl.t

I I I I II I I I , I I I I

90 80 7o 60 50 4o 30 2o loo 4 cyl.t I I I I I 1

60 50 40 3o 20 loo 6 cyl.

11 5 2 - 11 7 2 1

lmage selection - Superimposition. For this purpose, set beginning and end of the ignitionprocess on the left and right calibration lines.

Go-image - parade pattern (engine speeds above approx. 1OOWmin)

lJ(kV)

Bias voltage line

Ignition characteristic

Charging - ignition coil

+ - - - - - Opening 9: A_1 Closing 9 B

4 cyl. = 9o* 6 c y l .= 6 0 -

8 cyl. = 45

m=-Time

11 5 2 - 11715

Image selection - Parade pattern. Display image is elongated in horizontal direction.

15.11 II - 525/2

EXIT

8/6/2019 190E

23/48

Go-image - Superimposition (engine speeds above approx. OOQ/min)

U(kV)

4 5 O 4 0 " 3 5 " 3 0 " 2 5 " 2 0 " 1 5 O l o o 5 " a C Y I .t

I I I I 1 I II I I r I T I I 1 1 I I 1

9 0 " 8 0 " 7 o " 6 0 " 5 0 " 4 o "3 0 " 2 0 " 1 0 "

4 c y l .t r I 1 1 I 1 I

6 0 ' 5 0 " 4 o " 3 0 " 2 o " l o o ' 6 cyl.

1152 - 1 1 7 1 9

Image selection - Superimposition. For this purpose, set beginning and end of the ignitionprocess on the left and right calibrating lines.

Too high but regular ignition curve starting point

lJ(kV)

Image selection Superimposition.Visible Idle speed on one or several cylinders

1 5 . 1 1 II - 5 2 5/ 3

EXIT

8/6/2019 190E

24/48

U(kV)

Image selection Parade pattern.Image error Ignition curve starting point above 1.5 kV.Visible Idle speed on one or several cylinders.Cause Too high ohmic resistance on the secondary side due to spark plug connector,

distributor rotor, distributor cap, ignition cable, spark plug.Remedy Renew parts with too high ohmic resistance (use ohmmeter).

U(kV)

1 1 5 2 - 1 1 7 2 4 I

Image selection Parade pattern.Image error Ignition curve starting point above 1.5 kV.Visible Idle speed on all cylinders.Cause Too high ohmic resistance on the secondary side due to distributor rotor,

distributor cap or high-voltage cable no. 4 with plug.Remedy Renew parts with too high ohmic resistance (use ohmmeter).

-

EXIT

8/6/2019 190E

25/48

Required ignition voltage

U( k V )l o -

5 -

Zyl. 1 5 3 6 2 4 1

1153 -11717Image selection Parade pattern.Image error Cylinders 4, 5 and 6 require a higher ignition voltage than cylinders 1 , 2 and

3 (observe firing order).Visible idle speed.Cause Uneven mixture distribution.Remedy Check mixture distribution (e.g. fuel quantity comparitive measurement

0 7 . 3 4 6 0 ) .

1 5 . 1 1 i I - 5 2 %

EXIT

8/6/2019 190E

26/48

U(kV)1 0

Il?

Zyl 1 5 4 a 6 3 7 2 1

1152-402712

Image selection Parade pattern.Image error Cylinder 4 bias too low - ignition curve longer

Cylinder 2 bias too high - ignition curve shorter.Visible May occur at all speeds with or without engine load.Cause Cylinder 4 spark plug electrode gap too small, fuel-air mixture too rich, loss of

compression.

Remedy

Cylinder 2 spark plug electrode gap too great, fuel-air mixture too lean,additional spark gap on the secondary side.Bias too low: correct spark plug electrode gap, check cylinder for leaks.Bias too high: correct spark plug electrode gap, check distributor cap, ignition

cable and spark plug for continuity (use ohmmeter).

1 5 . 1 1 I I - 5 2 5 / 6

EXIT

8/6/2019 190E

27/48

Jumping ignition curve starting point

lJ(kV)

Image selection Parade pattern.Image error Ignition curve starting point changes, jumps.Visible Can be visible at all speeds with or without engine load.Cause Spark plug carbon-fouled, oil-fouled, burnt, insulation damage on spark plug

connector.Remedy Clean or renew spark plug, renew spark plug connector.

Required ignition voltage, intermittent acceleration load

U (kV)2 0 1

4! ma x . 3 - 4 k V

1152-482811

Image selection Parade pattern.Image error Increase of required ignition voltage by more than 4 kV.Visible Accelerate engine intermittently to approx. 3000Imin.Cause Spark plug electrode gap too large.Remedy Correct spark plug gap, renew spark plug if required.

1 5 . 1 1 I I - 5 2 5 / 7

EXIT

8/6/2019 190E

28/48

U (kV)lo-

Image selection Parade pattern.Image error The required ignition voltage increases by more than 4 kV on shortened ignition

curve, high increase of the oscillations in the opening sector above and below thezero line.

Visible With oscilloscope connected, start engine after prolonged inoperative period,repeatedly accelerate engine intermittently to approx. 3000Imin.

Cause Fuel-air mixture too lean.

Remedy Check injection valve, renew if required (07.3135, 07.3-215).

1 5 . 1 1 I I - 5 2 5 / 8

EXIT

8/6/2019 190E

29/48

Ignition coil - separate testgo

U(kV) ~ 1

8 voltage peaks

nogo

U(kV)

Image selection Parade pattern.Image error Voltage below 20 kV, less than 8 voltage peaks.Cause Winding interruption, interturn short-circuit or insulation damage to ground.Remedy Renew ignition coil.Note Do not exceed 28 kV as this will already damage the ignition coil.

1 5 . 1 1 I I - 5 2 5 1 9

EXIT

8/6/2019 190E

30/48

enewing spark plugs

Spark plug connector

Ignition cable cover .

Spark plugs . . . . . .

Job no. of the job texts and work units and standard texts and flatrates respectively . . . . . . . . . . . . . . . . . . . 1 5 1 0 3 1

A BC

Ia a

..................

..................

..................

loosen by turning to the left and right and pull off.Blow recesses with compressed air.remove and clean, when fitting, ensure correct

routing of ignition cables.for removal and installation use only approvedspark plug wrench (with Nm limitation 6).A 1 0 2 5 8 9 0 2 0 9 0 0B 162 589 01 09 00C on-board toolsInstall only approved spark plugs with tapered seat(a).Tightening torque 20 Nm

1 5 . 1 1 I I - 5 3 0 / l

EXIT

8/6/2019 190E

31/48

emoval and installation of high-voltage distributor

Job number of the iob texts and work units and standard textsand fllat rates respe&vely . . . . . . . . . . . . . . 1 S - 3 0 1 0

Cover on high-voltage distributor ..........

Distributor cap (4) . . . . . . . . . I ...........

Distributor rotor (2) . . . . . . . .

3 Sealing cover4 Distributor cap6 Shielding cap

pull up by unclipping the two straps (arrows).

remove by loosening the three socket-headscrews.Caution!

During removal and installation of the distributorcap (4), observe in particular that the carbondoes not contact the dome of the distributorrotor (2) with subsequent damage.

remove by loosening the three socket-headscrews (1) on the driver.

1 5 . 1 1 I I - 5 3 5 / l

EXIT

8/6/2019 190E

32/48

NoteAfter removal and installation of the high-voltagedistributor the ignition timing need no longer beadjusted. The ignition timing is determined bythe control unit.

Install the ignition cables on the distributor cap inthe sequence 1 , 3, 6, 2, 4, 5 so that the ignitioncables can be routed properly.

1 5 . 1 1 I I - 5 3 5 / 2

EXIT

8/6/2019 190E

33/48

15540 Checking the electronic i nition system with variablecharacteristics (

B1 l/2

G1LSN1/2R4R1 6

s 5 / 3

Job number of the job texts and work units and standard textsand fiat rates respectrvely . . . . . . . . . . . . . . 1 S-2450

N l /2_

Temperature sensor, coolant(EZUCIS-E/2 E-E)BatteryPosition pickup, crankshaftControl uinit transistonzed ignition system (EZL)Spark plugsReference resistor plug (EZL)

High-voltage distnbutor

S29l2 Throttle valve switch, full load/idle speeddetection

Tl Ignition coilx 1 1 Diagnostic socket/cable connector, terminal TD1 Segments on ftywheel/driven plate2 Vacuum pipe030 Engine tester with oscilloscope

Precondition for the following ignition system tests:Spark plugs, ignition gear, distributor rotor and distributor cap mechanically and electronically o.k.Check for instance by means of visual inspection, resistance measurement and ignition oscilloscope.

1 5 . 1 1 II 5 4 0 / l

EXIT

8/6/2019 190E

34/48

Test sequence - survey

A. Engine not running

Check dwell angle at starting speed.

Rated value: l-30 or l-50%

IYes Ino II

Check voltage supply.Check open-circuit current cutoff.Check position pickup.

Recheck dwell angle at startingspeed.

Check ignition timing at starting speed.

Rated value: TDC & 2 crankshaft

IYes Ino I

Check high-voltage distributor.

End of test

. Engine running

Check ignition timing.

Rated value: see 15515

Ye s Ino - - 1

Check reference resistor plug.Check throttle valve switch.Check pressure sensor.

Check temperature sensor coolant.

Check dwell ange at 3200/min.Check high-voltage distributor.Check voltage supply.Check ignition coil.

IEnd of test. I

NoteWhen complaint cannot be rectified, continuetrouble diagnosis in CIS-E injection system.

NoteWhen complaint cannot be rectified, continuetrouble diagnosis in CIS-E injection system.

1 5 . 1 1 I I - 5 4 0 1 2

EXIT

8/6/2019 190E

35/48

Test values

Resistances (test values from O-100 OC)

Voltages, engine not running, ignition switched on

1 Between terminals 15 and 1 (jacks and 5 and 4 diagnostic socket) V I0 I1Round plug 4-pole terminals 15 and 3 1 1 Battery voltage

Dwell angle

I At starting speed I l-30 or l-50% I1At 3200/min 124-53 or 40-88%

Ignition timing

IAt starting speed crankshaft 1 TD C + 2 I

1 5 . 1 1 I I - 5 4 0 / 3

EXIT

8/6/2019 190E

36/48

A. Engine fails to run

Check dwell angle at starting speedConnect measuring instruments.

Start engine.Check dwell angle on jack 1 of the diagnosticsocket.

Rated value: l-30 or l - 5 0 %

Check voltage supplyPull off 4-pole round supply plug onignition control unit.Switch on ignition.Measure voltage on plug betweenterminal 15 (corresponding to jack 5of the diagnostic socket) andterminal 3 1 .

Rated value: battery voltage.

Check ground cable.

Check open-circuit current cutoffCheck voltage differential between

jacks 5 and 4 (terminals 15 and 1) ofthe diagnostic socket.

Rated value: 0 volt

1 5 . 1 1 I I - 5 4 0 / 4

EXIT

8/6/2019 190E

37/48

Check position pickupSwitch off ignition.

Pull ignition pickup plug off ignitioncontrol unit. Measure pickup

resistance between terminals 7 and31d with the ohmmeter.

Rated value: 680-l 200 R

Renew position pickup.

Check position pickup for groundconnection.

Check resistance between terminal 7and vehicle ground.

Rated value: 2200 kQ or *

IYes Ino

Visual inspection of controlcable.Renew position pickup.

Check alternating voltage from theposition pickup with the oscilloscope.Pull off control cable.Measure alternating voltage betweenterminals 7 and 31d at startingspeed.

Rated value: Us 2 1 volt

I-es Ino

P 1 5 - 0 2 4 0 - 1 3

1 5 . 1 1 I I - 5 4 0 / 5

EXIT

8/6/2019 190E

38/48

Renew position pickup.If alternating voltage remainsbelow rated value, checksegments on theflywheel/driven plate.

t 1 1 st segmentt2 2nd segmentt3 3rd segmentd Penod for one crankshaft

rotation

Check dwell angle at startingspeedConnect measuring instruments.Start engine.Check dwell angle on jack 1 of thediagnostic socket (terminal TD).

Rated value: l - 3 0 " or l - 5 0 %

IYes Ino I

Check ignition timing at starting speed

Rated value: TDC -t 2

Ye s Ino I

Check ignition coil(Unscrew cables from the ignitioncoil).

Rated values:Terminals 1 and 15: 0.3-0.6 QTerminals 1 and 4: 8-13 kS2

IYes Ino

14 406

O l l S - 2 0 4 0 7

I IRenew ignition coil.

1 5 . 1 1 I I - 5 4 0 / 6

EXIT

8/6/2019 190E

39/48

Check high-voltage distributorVisually inspect distributor cap androtor.Measure interference suppressionresistors.

IEnd of test. I

. E n g i n er ur m ing

Check ignition timingEngine at operating temperature.Coolant temperature below 95 C .

Check ignition timing at idle speed.Check ignition timing at 3200/min with andwithout vacuum (disconnect vacuum line oncontrol unit).Observe reference resistor plug position.

Rated values: see 1 5 5 1 5

Check reference resistor pluga) Reference resistor plug (R16)Compare engine version andreference resistor plug lettering. Pull4-pole plug-pickup (arrow) off ignitioncontrol unit.Measure resistance value between

jack 3 and vehicle ground.

b) Individual reference resistorplug (W160)Compare national version and partnumber.Pull 4-pole plug-pickup (arrow) offignition control unit.Measure resistance value between

jack 3 and vehicle ground.

Ino

1 5 . 1 1 I I - 5 4 0 / 7

EXIT

8/6/2019 190E

40/48

a) Reference resistor plug(Rl6)Check resistance values in thereference resistor plug (betweenthe outer and center plug pins).

Rated values for all referenceresistor plugs:

A E 470 RB 2.4 kQ F 220 RC 1.3 kR G 0 R

D 750 R

b) Individual reference resistorplug (W16Il)Check resistance values measureresistance values on theindividual reference resistor plugbetween the two plug pins.

Part number Resistance Nationalvefslon

000 540 21 81 0 Q

000 540 22 81 220 R000 540 24 81 750 Sz

Ye s Ino-

Renewreferenceresistor plug.

Check cable to ignition control

unit.Check ground cable.Check plug lower part.

Ye s Ino

Renewdamaged parts.

P l 5 - 2 1 4 4 - 1 3

0 1 1 5 - 3 5 4 9 7

0 1 1 5 - 2 8 5 0 7

15.11 II - 540/8

EXIT

8/6/2019 190E

41/48

Disconnect vacuum line oncontrol unit.Run engine at approx. 1200/min(not idling).Ignition timing changes whenturning the reference resistorplug

Ye s Ino

Check throttle valve switchDisconnect coupling on throttle valveswitch.Check resistance of throttle valveswitch.

Idle speed positionFull loadPart load position

approx. 0 Qapprox. 0 Qapprox. 00 Sz

Ye s Ino

Check cable to ignition control unit.Check ground cables.

r-------Y

Q

8--

X56P \ s 2912hII1,23

1 5 . 1 1 I I - 5 4 0 / g

EXIT

8/6/2019 190E

42/48

8/6/2019 190E

43/48

Check temperature sensor, coolantDisconnect 4-pole plug-pickup on

control unit.Measure resistance between jack 1and ground.Rated value see diagram.Check resistance at twotemperatures.

Example:+ 2 0 C + 2.28-2,72 kS2+ 80 C ==+ 290-364 Q

Ye s Ino

Check cable.Renew temperaturesensor, coolant.

Check ignition timing at 3200/minwithout vacuum.

Rated value: see 15-515

50 00040000 'D

30000z

I

??

20000 0

1 0 0 0 08000

6000

4000

3000

2000

1 0 0 00 0 0

600

400

Ei 300

z 200

10 080

I I I I I I I {

40 ,I

I II I I I30 1 1 1

20

10 1

- 3 0 - 2 0 0 2 0 4 0 60 60 10 0 12 0 T

1 5 . 1 1 I I - 5 4 0 / 1 1

EXIT

8/6/2019 190E

44/48

Check dwell angle at 32OOIminVacuum line and 4-pole plug (pickup) onignition contol unit connected.Run engine at 3200/min.Check dwell angle

Rated value: 24-53 or 40-88%

Check high-voltage distributorVisually inspect distributor cap and rotor.Measure interference suppression resistors.

Rated value: 1 kSZ

Ye s Ino

Check voltage supplyMeasure voltage drop:Remove ignition coil cover.Connect measuring instrument to negativeterminal of battery.Run engine.Measure voltage on the positive terminal ofthe battery and subsequently on terminal 1 5of the ignition coil.

Rated value: voltage differential < 1 volt

Ye s Ino

1 5 . 1 1 I I - 5 4 0 1 1 2

EXIT

8/6/2019 190E

45/48

Check contact resistance:Loosen battery terminals.Pull 4-pole plug (supply) off ignitioncontrol unit. Switch on ignition.Measure resistance between positive

terminal and terminal 1 5 on the plug.Measure resistance between positiveterminal and terminal 15 on theignition coil.Measure resistance betweennegative terminal and terminal 31 onthe plug.Measure resistance between terminal1 on the ignition coil and terminal 16on the plug.

Rated value: < 1 Q

Check plug and screw

connections of the voltagesupply via ignition lock.Check ground cables.

Evaluate by means of oscillogram with

End of test.

1 5 . 1 1 I I - 5 4 0 1 1 3

EXIT

8/6/2019 190E

46/48

8/6/2019 190E

47/48

8/6/2019 190E

48/48