Misfiring of Cylinder 1

Misfiring of Cylinder 1 (P0301)

Test 1 Check Component T1/x (Ignition Coil(s)).
Test 2 Check Component Y62 (Fuel Injectors).

1 Check Component T1/x (Ignition Coil(s)). - Check Component T1/1 (Ignition Coil Cylinder 1).

Hazard as a result of high voltage at the ignition system!
- Electronic ignition systems operate within a hazardous power range both at the low voltage side (primary circuit) as well as on the high voltage side (secondary circuit).
- Contacts with such parts can result in burns, heart flutter or cardiac arrest.

Rules of conduct and protective measures
- Persons with heart pacemakers must not perform any work on the ignition system.
- Switch off the ignition when performing work on the ignition system.
- Do not touch any parts of the ignition system when starting the engine or when the engine is running.
- Wear protective shoes with rubber soles.
- Do not install any uninsulated adapters into the ignition cables.

Test 1-1 Test Secondary Voltage of Component T1/1 (Ignition Coil Cylinder 1).
Test 1-2 Test Primary Voltage of Component T1/1 (Ignition Coil Cylinder 1).
Test 1-3 Test Voltage Supply of Component T1/1 (Ignition Coil Cylinder 1).
Test 1-4 Test primary winding of component T1/1 (Ignition Coil Cylinder 1).

1-1 Test Secondary Voltage of Component T1/1 (Ignition Coil Cylinder 1).

Figure legend (The illustration shows the connection of the kV pickup at cylinder 5 (ignition circuit b) of engine M 113 as an example.)
- A2 Oscilloscope Lead
- A7 Oscilloscope Lead
- A Secondary adapter cable
- B kV pickup
- T1/5 (ignition coil cylinder 5)

Test sequence
- Switch off ignition.
- Connect the kV pickup with the secondary adapter cable to component T1/1 (Ignition Coil Cylinder 1) . (Ignition circuit a,Test b.)
- Connect the test cables ( A2 and A7) of the Star diagnosis measuring system to the sockets of the secondary adapter cable (see ill.).
- A7 <--> A2
- Operate the starter and run the engine if possible.

Settings
- Measured range: 25 kV
- Time range: 5 ms

Specified value
- If necessary compare the signal images of the various cylinders with each other.

Note
- Measuring system HMS990 integrated in STAR DIAGNOSIS, is required for performing the next test step.Switch on measuring system HMS990 for this step.Continue with key F3
- If measuring system HMS990 is not integrated in your STAR DIAGNOSIS, it is also possible to carry out the next tests with alternative measuring equipment such as oscilloscope, pressure gage or digital multimeter.Continue with key F4

Question
- Is measuring system HMS990 to be started?

Question
- Was the test o.k.?
Yes
The test was okay. ** End of Test **
No
The test was not okay.
Possible cause and remedy
- Test primary voltage of component T1/1 (Ignition Coil Cylinder 1) .
- Test voltage supply of component T1/1 (Ignition Coil Cylinder 1) .
- T1/1 (Ignition Coil Cylinder 1)
Further possible causes of fault
- R4 (Spark plugs)
- Spark plug connector
- Ignition cable

** End of Test **

1-2 Test Primary Voltage of Component T1/1 (Ignition Coil Cylinder 1).

Figure legend
- 1 Primary voltage
- 2 Combustion voltage curve
- 3 Signal decay
- t Combustion period

Settings
- Measured range: 100 V
- Time range: 5 ms

Specified values
- Primary voltage: [250...400] V
- Combustion period: [0.8...2.0] ms
- Number of oscillations: [2...5]
- If necessary compare the signal images of the various cylinders with each other.

Note
- Measuring system HMS990 integrated in STAR DIAGNOSIS, is required for performing the next test step.Switch on measuring system HMS990 for this step.Continue with key F3
- If measuring system HMS990 is not integrated in your STAR DIAGNOSIS, it is also possible to carry out the next tests with alternative measuring equipment such as oscilloscope, pressure gage or digital multimeter.Continue with key F4

Question
- Is measuring system HMS990 to be started?

Question
- Was the test o.k.?
Yes
The test was okay. ** End of Test **
No
The test was not okay.
Possible cause and remedy
- Test voltage supply of component T1/1 (Ignition Coil Cylinder 1)
- Test primary winding of component T1/1 (Ignition Coil Cylinder 1)
- R4 (Spark plugs)
- T1/1 (Ignition Coil Cylinder 1)

** End of Test **

1-3 Test Voltage Supply of Component T1/1 (Ignition Coil Cylinder 1).

Figure legend (The illustration shows the connection of the primary adapter cable at cylinder 5 of engine M 113 as an example.)
- D Primary adapter cable
- T1/5 (ignition coil cylinder 5)
- a Yellow socket=Ignition circuit a (Terminal 1)
- b Green socket=Ignition circuit b (Terminal 1)
- c Blue socket=Voltage supply

Test sequence
- Switch off ignition.
- Connect Primary adapter cable to component T1/1 (Ignition Coil Cylinder 1) .
- a <--> b
- Note: The two primary windings are connected in series during the measurement and are thus tested simultaneously.

Specified value
- Resistor[0.9...1.6] ohms

Question
- Is the measured value okay?
Yes
The measured value is o.k. ** End of Test **
No
The measured value is not o.k.
Possible cause and remedy
- T1/1 (Ignition Coil Cylinder 1)

** End of Test **

2 Check Component Y62 (Fuel Injectors). - Check Component Y62y1 (Cylinder 1 Injector).

Warning! Risk of explosion, poisoning and injury!Fuels are highly inflammable and toxic if inhaled. Fuels may cause skin damage. fuel vapors are explosive, invisible and spread out at floor level; they are toxic if inhaled and produce giddiness and an anaesthetizing effect.

Rules of conduct and protective measures
- Wear suitable protective clothing.
- Pay attention to national safety precautions and regulations.
- No fire, sparks, naked flames and smoking.
- Ensure the work place is adequately ventilated.
- Never drain or pour in fuels over assembly pits.
- Store drained fuel in a suitable and sealed vessel.
- Immediately eliminate any fuel which has flowed out.

First-aid measures
- Clean moistened skin with water and soap.
- Change moistened clothing as quickly as possible.
- If fuel gets into your eyes, rinse out your eyes immediately with water and contact a doctor if necessary.

Test 2-1 Test Actuation of Component Y62y1 (Cylinder 1 Injector).
Test 2-2 Check Component Y62y1 (Cylinder 1 Injector) Using Actual Value.
Test 2-3 Test Internal Resistance of Component Y62y1 (Cylinder 1 Injector).
Test 2-4 Inspect Component Y62y1 (Cylinder 1 Injector) For Leaks.
Test 2-5 Inspect Operation and Spray Pattern of Component Y62y1 (Cylinder 1 Injector).
Test 2-6 Test Signal Voltage of Component Y62y1 (Cylinder 1 Injector).

2-1 Test Actuation of Component Y62y1 (Cylinder 1 Injector).

Test requirement
- The engine is running.

Note: Component M4/3 (engine/AC electric suction fan) runs with an on/off ratio of 50 % during the actuations for safety reasons.

Note! Communication with ECU required.

2-2 Check Component Y62y1 (Cylinder 1 Injector) Using Actual Value.

Test sequence
- Run engine.

Note
- The actual value indicated (Injection time, right) represents the internal computed quantity in control module ME motor electronics. This means that the actual value is displayed irrespective of the function of the injectors.

Status of the relevant actual values:
- Temperature of coolant: Note! Communication with ECU required
- Injection time, right: Note! Communication with ECU required
- Injection time, left: Note! Communication with ECU required

Specified values
- 20 °C The value is ms at a coolant temperature of approx. [7...12] and when engine is started.
- 80 °C The value is ms at a coolant temperature of approx. [2.7...4.4] and when engine is idling.
- 80 °C The value is ms at a coolant temperature of approx. [14.0...20.0] and when the throttle is blipped.

Question
- Are the actual values o.k.?
Yes
The actual values are okay.
Further possible causes of fault
- Test wiring to component Y62y1 (Cylinder 1 injector) .
- Test internal resistance of component Y62y1 (Cylinder 1 injector) .
- Inspect component Y62y1 (Cylinder 1 injector) for leaks.
- Inspect operation and spray pattern of component Y62y1 (Cylinder 1 injector) .
No
Question
- Fault code present P201D?
Yes
The actual values are not okay.
Possible cause and remedy
- Test wiring to component Y62y1 (Cylinder 1 injector) .
- Test internal resistance of component Y62y1 (Cylinder 1 injector) .
No
The actual values are not okay.
Possible cause and remedy
- Inspect component Y62y1 (Cylinder 1 injector) for leaks.
- Inspect operation and spray pattern of component Y62y1 (Cylinder 1 injector) .

** End of Test **

2-3 Test Internal Resistance of Component Y62y1 (Cylinder 1 Injector).

Test sequence
- Switch off ignition.
- Connect socket box (126-pin) to component N3/10 (ME-SFI control module).
- Connect socket box (35-pin) to component N3/10 (ME-SFI control module).
- (3.27) Pin 60 of 126 <--> Pin 9 of 35 (5.9)

Specified value
- Resistor[14...18] ohms

Question
- Is the measured value okay?
Yes
The measured value is o.k.
Note
- If stored faults present with high fault frequency counter or if customer complaints exist, inspect cables and plug connections for loose contact and corrosion.
No
The measured value is not o.k.

Test sequence
- Switch off ignition.
- (Y62) 1 <--> 2 (Y62)

Specified value
- Resistor[14...18] ohms

Question
- Is the measured value okay?
Yes
The measured value is o.k.
Possible cause and remedy
- Leads to component Y62y1 (Cylinder 1 injector)
No
The measured value is not o.k.
Possible cause and remedy
- Y62y1 (Cylinder 1 injector)

** End of Test **

2-4 Inspect Component Y62y1 (Cylinder 1 Injector) For Leaks.

Figure legend
- 055 Measuring beaker
- Y62 (Fuel injectors)

Test sequence
- Switch off ignition.
- Remove fuel rail together with component Y62 (Fuel injectors).
- Connect socket box (35-pin) to component N3/10 (ME-SFI control module).
- Connect socket box (126-pin) to component N3/10 (ME-SFI control module).
- (5.7) Pin 7 of 35 <--> Pin 121 of 126 (4.36)
- Switch on ignition.

Specified value
- Component Y62y1 (Cylinder 1 injector) must not drip.

Question
- Was the test o.k.?
Yes
The test was okay.
Further possible causes of fault
- Inspect operation and spray pattern of component Y62y1 (Cylinder 1 injector).
No
The test was not okay.
Possible cause and remedy
- Y62y1 (Cylinder 1 injector)

** End of Test **

2-5 Inspect Operation and Spray Pattern of Component Y62y1 (Cylinder 1 Injector).

Figure legend 1
- 001 Sockets of component N3/10 (ME-SFI control module)
- 048 Shop-made tool(Test wiring harness)
- 050 126-pin socket box
- 055 Measuring beaker
- 108 Test cable N3/10 (ME-SFI control module)
- N3/10 (ME-SFI control module)
- II 1/63 Connection Test cable
- II 64/126 Connection Test cable

Figure legend 2 (Shop-made tool)
- 1x Clutch 140 545 35 28
- 2x Contact spring 004 545 56 26
- 1x Red banana connector
- 1x Black banana connector
- 2,2 m Red cable with diameter 1,5 mm (Pin 1)
- 2,2 m Brown cable with diameter 1,5 mm (Pin 2)
- 2 m Insulation sheathing with diameter 6 mm

Test sequence
- Switch off ignition.
- Remove fuel rail together with component Y62 (Fuel injectors).
- Connect socket box (35-pin) to component N3/10 (ME-SFI control module).
- Connect socket box (126-pin) to component N3/10 (ME-SFI control module).
- Insert bridge.:
- (5.7) Pin 7 of 35 <--> Pin 121 of 126 (4.36)
- Switch on ignition.
- Note: Component M3 (fuel pump) runs.
- Hold component Y62y1 (Cylinder 1 injector) in a vessel and briefly operate manually with shop-made test cable set at sockets 5 and 9 of the 35-pin socket box.

Specified value
- Fuel injectors should eject fuel uniformly.

Question
- Was the test o.k.?
Yes
The test was okay. ** End of Test **
No
The test was not okay.
Possible cause and remedy
- Y62y1 (Cylinder 1 injector)

** End of Test **

2-6 Test Signal Voltage of Component Y62y1 (Cylinder 1 Injector).

Test sequence
- Switch off ignition.
- ConnectionMeasuring system
- (3.27) Pin 60 of 126 <--> Pin 9 of 35 (5.9)
- Run engine.

Note
- Measuring system:Continue with key F2

Note
- Measuring system HMS990 integrated in STAR DIAGNOSIS, is required for performing the next test step.Switch on measuring system HMS990 for this step.Continue with key F3
- If measuring system HMS990 is not integrated in your STAR DIAGNOSIS, it is also possible to carry out the next tests with alternative measuring equipment such as oscilloscope, pressure gage or digital multimeter.Continue with key F4

Question
- Is measuring system HMS990 to be started?

Question
- Is the measured value okay?
Yes
The measured value is o.k. ** End of Test **
No
The measured value is not o.k.
Possible cause and remedy
- Cable N3/10 (ME-SFI control module) - Y62y1 (Cylinder 1 injector) has loose contact, corrosion or is damaged.
- N3/10 (ME-SFI control module)

** End of Test **