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Diagnostic Manual, Engines, Volume 2

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 1.1  HFM Sequential Multiport Fuel Injectin/Ignition System (HFM-SFI)   >   23 Electrical Test Program - Sequential Multiport Fuel Injection System Test


Electrical Test Program - Sequential Multiport Fuel Injection System Test

Test scope Test connection Test condition Nominal value Possible cause/Remedy
1.0   Engine control module
(HFM-SFI) (N3/4)
Voltage supply
Circuit 30

33 (1.33)
N3/4



40
(1.40)
Ignition: ON
11 - 14 V
1.1


1.1   Ground wire N3/4

33 (1.33)


X11/4

2 1)
Ignition: ON 11 - 14 V Ground wire, Model 124
Battery ground (W10),
Model 129
Ground, module box bracket (W27),
Model 140
Wiring harness ground, right footwell (W15),
Model 202, 210
Ground (component compartment - right [W16/4]),
1.2
1.2   Voltage supply
Circuit 30 		X11/4

1


N3/4

40
(1.40)
Ignition: ON 11 - 14 V Wire to terminal block X4/10 or X4/22.
2.0 1 1 0
1 1 1 		Engine control module
(HFM-SFI) (N3/4)
Voltage supply
Circuit 87U


32
(1.32)
N3/4



39
(1.39)
Ignition: ON 11 - 14 V 2.1
2.1   Electronics ground N3/4

32
(1.32)


X11/4

2 1)
Ignition: ON 11 - 14 V Wiring, Model 124
Electronic ground (W10/1),
Model 129 and 140
Electronic ground, right footwell (W15/1),
Model 202, 210
Ground in component compartment right, electronic ground (W16/6),
2.2
2.2   Voltage supply
Circuit 87U 		X11/4

1


N3/4

39
(1.39)
Ignition: ON



Ignition: OFF 		11 - 14 V



< 1 V
Wiring,
Overvoltage protection relay
module (K1/2), base module (N16/1) or relay module (K40),
Ignition/starter switch (S2/1).
3.0   Engine control module
(HFM-SFI) (N3/4)
Voltage supply
Circuit 87M

66
(2.22)
N3/4



27
(1.27)
Ignition: ON

11 - 14 V Wiring,
Fuse,
Overvoltage protection relay
module (K1/2), base module (N16/1) or relay module (K40),
3.1
3.1   Electronics ground N3/4

66
(2.22)


X11/4

2 1)
Ignition: ON 11 - 14 V Wiring, Model 124
Electronics ground (W10/1),
Model 129 and 140
Electronic ground, right footwell (W15/1),
Model 202, 210
Electronic ground in component compartment right (W16/6),
4.0 0 0 9
0 1 0 		Hot film MAF sensor (B2/5)
Voltage at hot film

71
(2.27)
N3/4



49
(2.5)
Engine: at Idle

Engine coolant
temperature >70°C

0.8 - 1.1 V 2) 		Wiring,
4.1 ,
5.0 ,
Air intake system leak,
B2/5.
4.1   Voltage supply

71
(2.27)
N3/4



39
(1.39)
Ignition: ON

11 - 14 V Wiring,
Engine control module (N3/4).
5.0 0 0 9
0 1 0 		Ground wire for hot film MAF sensor (B2/5)

4
B2/5



2
Disconnect connector on B2/5 and measure directly at sockets 2 (rt/bl) and 4 (br).
Ignition: ON
11 - 14 V Ground wire.
6.0 0 7 6 FP relay module (K27) or relay module (K40)
Control signal

32
(1.32)
N3/4



29
(1.29)
Engine: Start 6 - 14 V
while cranking. 		6.1 ,
N3/4.
6.1   Current draw

29
(1.29)
N3/4



39
(1.39)
Ignition: ON 0.1 - 0.3 A Wiring,
K27 or
K40
7.0 1 0 1 Starter signal
Circuit 50

32
(1.32)
N3/4



21
(1.21)
Engine: Start 6 - 14 V
while cranking. 		Wiring.
8.0 0 0 2
0 0 3
0 0 4
0 0 5 		ECT sensor (B11/3)
Voltage

72
(2.28)
N3/4



80
(2.36)
Ignition: ON
C °
    		V 8.1 ,
Engine control module (N3/4).
20 3.5
30 3.1
40 2.7
50 2.3
60 1.9
70 1.5
80 1.2
90 1.0
100 0.8
  ±5%
8.1   Resistance

72
(2.28)
N3/4



80
(2.36)
Ignition: OFF
Unplug connector 2
on engine control
module (N3/4).
C °
   
Wiring,
B11/3.
20 2500
30 1700
40 1170
50 830
60 600
70 435
80 325
90 245
100 185
  ± 5%
9.0 0 0 6
0 0 7
0 0 8 		IAT sensor (B17)
Voltage

72
(2.28)
N3/4



81
(2.37)
Ignition: ON
C °
    		V 9.1 ,
Engine control module (N3/4).
10 3.2
20 2.6
30 2.1
40 1.6
50 1.2
60 0.9
70 0.7
80 0.5
  ± 5%
9.1   Resistance

72
(2.28)
N3/4



81
(2.37)
Ignition: OFF
Unplug connector 2
on engine control
module (N3/4).
C °
    		Wiring,
B17.
10 9670
20 6060
30 3900
40 2600
50 1760
60 1220
70 860
80 620
  ± 5%
10.0 0 7 0
0 7 1 		Engine control module (N3/4)
TN-signal output
(engine rpm output signal)

32
(1.32)




32
(1.32)
N3/4 3)




N3/4 4)



18
(1.18)




18
(1.18)
Engine: Start or
Engine: at Idle 		Signal, see
Figure 1.






5 - 7.5 V 		Wiring,
Engine control module (N3/4).
11.0   Closed throttle position recognition signal
EA/CC/ISC actuator (M16/1) or CC/ISC actuator (M16/2)

32
(1.32)
N3/4



10
(1.10)
Ignition: ON
Accelerator pedal in closed throttle position.

Accelerator pedal in wide open throttle position.


4.8 V




5.5 V 		Wiring,
M16/1 or M16/2 (see electronic accelerator or cruise control/idle speed control tests in Diagnostic Manual, Engines, Volume 3, sections 6 or 7).
12.0 1 0 4 Fuel safety shut-off
from
EA/CC/ISC actuator (M16/1)
or
CC/ISC actuator (M16/2)


32
(1.32)
N3/4



4
(1.4)
Ignition: ON 2.2 - 11 V
(voltage fluctuates)
Wiring,
M16/1 or M16/2 (see electronic accelerator or cruise control/idle speed control tests in Diagnostic Manual, Engines, Volume 3, sections 6 or 7).
13.0. 1 0 4 Fuel safety shut-off

32
(1.32)
N3/4



4
(1.4)
Engine: Start and apply wide open throttle. Engine speed surges between 1000 - 2000 rpm. Engine control module (N3/4).
14.0 0 2 3
0 2 4
0 2 5 		O2S 1 (before TWC) (G3/2)
O2S 1 signal

34
(1.34)
N3/4



35
(1.35)
Engine: at Idle
and at operating temperature > 80 °C let engine run for a minimum of 2 minutes.
Oscillates between
- 0.2 and + 1.0
V by more than
0.3 V 		Wiring,
G3/2,
14.1 ,
15.0
14.1   Insulation, O2S 1 wire

35
(1.35)
N3/4



36
(1.36)
Ignition: OFF
Unplug connector 1 on N3/4. 		>20 k Wiring.
15.0 0 2 9
0 3 0
0 3 1 		O2S 1 (before TWC) (G3/2)
O2S 1 heater
Control signal

32
(1.32)
N3/4



30
(1.30)
Engine: at Idle
and at operating temperature > 80 °C let engine run for a minimum of 2 minutes.
11 - 14 V 15.1 ,
N3/4.
15.1   Current draw

30
(1.30)
N3/4



39
(1.39)
Ignition: ON 0.6 - 3.4 A Wiring,
G3/2.
16.0 0 2 6
0 2 7
0 2 8 		Except model 124
Perform both measurements simultaneously
O2S 2 (after TWC) (G3/1)
O2S 2 signal






Note to Test connection:
Connect second multimeter

Except model 210

O2S 2 (after TWC) heater relay module (K35)
Control signal

24
(1.24)















31
(1.31)
N3/4















N3/4



25
(1.25)















27
(1.27)
Start engine at engine coolant temperature
> 80°C.

Maintain an engine speed of 2000 - 3000 rpm for approx. 3 minutes until O2S 2 (after TWC) heater is switched on (see second multimeter or HHT).

Accelerate briefly.



O2S 2 (after TWC) heater not switched on.

O2S 2 (after TWC) heater switched on.

Note:
After the O2S 2 (after TWC) heater is switched on, the O2S signal must change.

450 mV
constant

Voltage
changes










Voltage
changes by
> 100 mV


11 - 14 V




< 1 V 		Wiring,
16.1 ,
17.0 ,
18.0 ,
G3/1.
16.1   Insulation, O2S 2 wire

25
(1.25)
N3/4



26
(1.26)
Ignition: OFF
Unplug connector 1 on engine control
module (N3/4).
>20 k Wiring.
17.0 0 3 2
0 3 3
0 3 4 		Except model 124
O2S 2 (after TWC) (G3/1)
O2S 2 heater
Control signal

32
(1.32)
N3/4



41
(1.41)
Engine: at Idle
and at operating temperature > 80 °C let engine run for a minimum of 2 minutes.
11 - 14 V 17.1.
Engine control module (N3/4).
17.1   Current draw

41
(1.41)
N3/4



39
(1.39)
Ignition: ON 0.6 - 3.4 A Wiring,
O2S 2 (after TWC) heater relay module (K35),
O2S 2 (G3/1).
18.0 1 0 8
1 0 9 		Except model 124, 210

O2S 2 (after TWC) heater relay module (K35)
Control signal

31
(1.31)
N3/4



27
(1.27)
Disconnect ECT sensor (B11/3) and simulate 2.5 k at sockets 1 and 2 with resistance substitution unit.
Engine: at Idle
11 - 14 V 18.1 ,
N3/4.
18.1   Current draw

33
(1.33)
N3/4



31
(1.31)
Ignition: ON

0.1 - 0.3 A Wiring,
K35.
19.0 0 3 7
0 3 8 		Injector (Y62y1)
Control and injection time



67
(2.23)

N3 / 4





39
(1.39)
ECT approx. 20 °C

at start

ECT approx. 80 °C
at idle
accelerate briefly 		Injection time:


approx. 8 ms

approx. 3 - 5 ms
approx. 17 ms
(see signals,
Figures 2 and 3)
19.1 ,
Engine control module (N3/4),

Further possibilities:
ECT sensor (B11/3),
IAT sensor (B17),
O2S 1 (G3/2).
19.1   Resistance

67
(2.23)
N3 / 4



53
(2.9)
Ignition: OFF
Connector 2 on engine control module unplugged. 		14 - 17
Wiring,
Y62y1.
20.0 0 3 9
0 4 0 		Injector (Y62y2)
Control and injection time


57
(2.13)

N3 / 4




39
(1.39)
ECT approx. 20 °C

at start
ECT approx. 80 °C

at idle
accelerate briefly 		Injection time:


approx. 8 ms



approx. 3 - 5 ms
approx. 17 ms
(see signals,
Figures 2 and 3)
20.1 ,
Engine control module (N3/4),

Further possibilities:
ECT sensor (B11/3),
IAT sensor (B17),
O2S 1 (G3/2).
20.1   Resistance

57
(2.13)
N3 / 4



53
(2.9)
Ignition: OFF
Connector 2 on engine control module unplugged. 		14 - 17 Wiring,
Y62y2.
21.0 0 4 1
0 4 2 		Injector (Y62y3)
Control and injection time



46
(2.2)


N3 / 4





39
(1.39)
ECT approx. 20 °C

at start
ECT approx. 80 °C

at idle
accelerate briefly 		Injection time:


approx. 8 ms



approx. 3 - 5 ms
approx. 17 ms
(see signals,
Figures 2 and 3)
21.1 ,
Engine control module (N3/4),

Further possibilities:
ECT sensor (B11/3),
IAT sensor (B17),
O2S 1 (G3/2).
21.1   Resistance

46
(2.2)
N3 / 4



53
(2.9)
Ignition: OFF
Connector 2 on engine control module unplugged. 		14 - 17 Wiring,
Y62y3.
22.0 0 4 3
0 4 4 		Injector (Y62y4)
Control and injection time



47
(2.3)


N3 / 4





39
(1.39)
ECT approx. 20 °C

at start

ECT approx. 80 °C
at idle
accelerate briefly 		Injection time:


approx. 8 ms



approx. 3 - 5 ms
approx. 17 ms
(see signals,
Figures 2 and 3)
22.1 ,
Engine control module (N3/4),

Further possibilities:
ECT sensor (B11/3),
IAT sensor (B17),
O2S 1 (G3/2).
22.1   Resistance

47
(2.3)
N3 / 4



53
(2.9)
Ignition: OFF
Connector 2 on engine control module unplugged. 		14 - 17 Wiring,
Y62y4.
23.0 0 4 5
0 4 6 		Injector (Y62y5)
Control and injection time



56
(2.12)


N3 / 4





39
(1.39)
ECT approx. 20 °C

at start

ECT approx. 80 °C
at idle
accelerate briefly 		Injection time:

approx. 8 ms


approx. 3 - 5 ms
approx. 17 ms
(see signals,
Figures 2 and 3)
23.1 ,
Engine control module (N3/4),

Further possibilities:
ECT sensor (B11/3),
IAT sensor (B17),
O2S 1 (G3/2).
23.1   Resistance

56
(2.12)
N3 / 4



53
(2.9)
Ignition: OFF
Connector 2 on engine control module unplugged. 		14 - 17 Wiring,
Y62y5.
24.0 0 4 7
0 4 8 		Injector (Y62y6)
Control and injection time



68
(2.24)


N3 / 4





39
(1.39)
ECT approx. 20 °C

at start

ECT approx. 80 °C
at idle
accelerate briefly 		Injection time:


approx. 8 ms



approx. 3 - 5 ms
approx. 17 ms
(see signals,
Figures 2 and 3)
24.1 ,
Engine control module (N3/4),

Further possibilities:
ECT sensor (B11/3),
IAT sensor (B17),
O2S 1 (G3/2).
24.1   Resistance

68
(2.24)
N3 / 4



53
(2.9)
Ignition: OFF
Connector 2 on engine control module unplugged. 		14 - 17 Wiring,
Y62y6.
25.0 0 6 8
0 6 9 		Non-USA vehicles only.
Continue to next test step.

 


 


 
     
26.0 0 7 7
0 7 8 		Non-USA vehicles only.
Continue to next test step.
 
     
27.0 0 7 2
0 7 3 		Non-USA vehicles only.
Continue to next test step.
 
     
28.0 0 8 5 Models 124, 129, 140:
Electromagnetic AIR pump clutch (Y33) and AIR pump switchover valve (Y32)

Model 202, 210:
AIR pump switchover valve (Y32) and AIR relay
module (K17)
Control signal


32
(1.32)
N3/4



59
(2.15)
Disconnect ECT sensor (B11/3) and simulate 2.5 k at sockets 1 and 2 with resistance substitution unit.
Engine: at Idle
11 - 14 V
(for approx. 2 minutes after start and AIR pump runs) 		28.1 ,
Engine control module (N3/4).
28.1   Current draw

59
(2.15)
N3/4



39
(1.39)
Ignition: ON Models 124, 129, 140
3.0 - 4.5 A

Model 202, 210
0.4 - 0.7 A 		Wiring,
Models 124, 129, 140
Y32,
Y33.
Model 202, 210
Y32,
K17.
29.0 0 8 6
0 8 7 		Purge control valve (Y58/1)
Control signal

43
(1.43)
N3/4



39
(1.39)
Engine: at Idle
and at operating temperature. 		After approx. 1 minute, purge control valve (Y58/1, Figure 5) must cycle noticeably (signal, see Figure 4).
29.1 ,
30.0 ,
Engine control module (N3/4).
29.1   Current draw

32
(1.32)
N3/4



43
(1.43)
Ignition: ON 0.2 - 0.3 A Wiring,
Purge control valve (Y58/1).
30.0   Purge control valve (Y58/1)
Vacuum control
 

 
Note to test connection:
Connect vacuum tester to Y58/1 (Figure 5), connection (A).

Engine: at Idle and at operating temperature.








After approx. 1 minute,
> 400 mbar
Vacuum lines,
Y58/1.
31.0 0 8 9
0 9 0 		Adjustable camshaft timing solenoid (Y49)
Current draw

1

Y49


2
Note to test connection:
Connect test cable
(102 589 04 63 00) to solenoid.

Engine: Start and raise engine speed to approx. 3000 rpm.
Briefly approx.
1.5 A,
then 1 A 		31.1 ,
32.0 ,
N3/4.
31.1   Resistance

45
(2.1)
N3/4



53
(2.9)
Ignition: OFF 4 - 8 Wiring,
Y49.
32.0   Adjustable camshaft timing solenoid (Y49)
Mechanical operation


45
(2.1)
N3/4



66
(2.22)
Engine: at Idle

Bridge socket box sockets for maximum of 10 seconds.


Engine runs unevenly or stalls
Mechanical camshaft adjustment
(see SMS, Repair Instructions, Engine 104, Job No. 05-216).
33.0 1 0 5
1 0 6 		Resonance intake manifold switchover valve (Y22/6)
Control signal

58
(2.14)
N3/4



39
(1.39)
Engine: Start
Engine speed: < 3900 rpm

Engine speed: > 3900 rpm


0 V

11 - 14 V
33.1 ,
Engine control module (N3/4).
33.1   Current draw

32
(1.32)
N3/4



58
(2.14)
Ignition: ON 0.4 - 0.6 A Wiring,
Y22/6.
34.0 0 8 8 Upshift delay switchover valve (Y3/3)
Current draw

42
(1.42)
N3 / 4



39
(1.39)
Ignition: ON 0.4 - 0.6 A Wiring,
Y3/3,
35.0
35.0   Pneumatic upshift delay
Vacuum control and sealing

42
(1.42)
N3 / 4



39
(1.39)
Note to test connection:
Connect vacuum tester to upshift delay switchover valve (Y3/3) according to Figure 13 and connect bridge.

Engine: at Idle











> 400 mbar
Vacuum lines,
Y3/3.
36.0 0 9 8
0 9 9
1 0 0 		Serial data bus (CAN)



L
N3/4

H
Ignition: OFF

55 - 65 36.1 ,
37.0 ,
Data line.
36.1   CAN element in CC/ISC (N4/3) or EA/CC/ISC (N4/1) control module

RCL control
module (N54) 5)
Resistance



L
N4/1
N4/3
N54



H
Remove N4/3, N4/1 or N54 control module and measure resistance directly at control module (see Figure 8 to 10 and 15).
115 - 125 N4/1, N4/3 or N54.
37.0 0 9 7 CAN element in engine control module
Resistance
L
N3/4

H
Ignition: OFF

Models 124, 129, 140, 202, 210 as of 6/95
Unplug connector 1 on N3/4 and measure resistance directly at engine control module (Figure 11).

Models 129, 140 up to 5/95
Remove N3/4 and measure resistance directly at engine control module (Figure 12). 		115 - 125 Engine control module (N3/4)
38.0 0 9 1
0 9 2 		EGR switchover
valve (Y27)
Vacuum control

69
(2.25)
N3 / 4



39
(1.39)
Engine: at Idle
Engine coolant
temperature > 60 °C
Apply briefly full throttle.
11 - 14V 38.1 ,
Engine control module (N3/4),
39.0 - 40.0
38.1   Current draw

32
(1.32)
N3 / 4



69
(2.25)
Ignition: ON 0.3 - 0.5 A Fuse,
Wiring,
Y27.
39.0   EGR switchover
valve (Y27)
Vacuum control 		 
Note to test connection:
Connect vacuum tester to the EGR valve (Figure 14).

Engine control module (N3/4) plugged in.
Engine: Start and run at
> 3000 rpm.












> 400 mbar 		EGR valve.
40.0   EGR valve
Mechanical test 		 
Note to test connection:
Connect vacuum tester directly to EGR valve.
Engine: at Idle
Apply 500 mbar vacuum with vacuum tester.

Engine: Off
Apply 500 mbar vacuum with vacuum tester and pull off vacuum line.





Engine runs unevenly




EGR valve closes audibly 		EGR valve.
41.0   Non-USA vehicles only.
Continue to next test step.
 
     
42.0   P/N position recognition

5-speed AT only!

20
(1.20)
N3/4



39
(1.39)
Ignition: ON
Selector lever position:
P
R
N
D - 3 - 2


11 - 14 V
< 1 V
11 - 14 V
< 1 V 		Wiring,
Starter lock-out/backup lamp switch (S16/1).
43.0   Non-USA vehicles only.
Continue to next test step.
 
     
44.0   Non-USA vehicles only.
Continue to next test step.
 
     
45.0   Models 129, 140, 202, 210
O2S 1 (before TWC) (G3/2)
O2S 1 signal for diagnostic module (OBD II)

34
(1.34)
N3/4



15
(1.15)
Engine: at Idle
and at operating temperature > 80 oC let engine run for a minimum of 2 minutes.
Oscillates in range between
-0.2 and+1.0 V by more than 0.3 V 		Wiring,
Engine control module (N3/4).
46.0   Models 129, 140, 202, 210
O2S 2 (after TWC) (G3/1)
O2S 2 signal for diagnostic module (OBD II)

24
(1.24)
N3/4



16
(1.16)
At operating temperature > 80 oC start engine.


and run at 2000 - 3000 rpm for a minimum of 3 minutes.

Accelerate briefly.
450 mV constant.



Voltage fluctuates.




Voltage fluctuates by >100 mV
Wire,
N3/4.
47.0   Models 129, 140, 202
CMP sensor (L5/1)
Signal for diagnostic module (OBD II)

Model 210
Camshaft Hall-effect sensor (B6/1)
Signal for diagnostic module (OBD II)


32
(1.32)



17
(1.17)
N3/4




N3/4



17
(1.17)



27
(1.27)
Engine: at Idle




Engine: at Idle 		9.5 - 10.5 V




1.3 - 1.7 V
Value fluctuates 		Wiring,
N3/4.
48.0   Fuel consumption signal

7
(1.7)
N3/4



39
(1.39)
Engine: at Idle


Accelerate briefly. 		approx. 0.85 V


> 1 V 		Wiring,
Engine control module (N3/4).

1) For models 129, 140 and 202. On model 124, connect to socket 16.
2) Voltage increases with increasing rpm.
3) Test with oscilloscope.
4) Test with multimeter only if oscilloscope is not available.
5) As of model year 1996.



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