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Pete
Pete, Mercedes Mechanic
Category: Mercedes
Satisfied Customers: 24728
Experience:  Over 15 years experience as a Mercedes dealer technician
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2000 MERCEDES ML320 WILL STALL SOMETIMES WHEN BRAKING AND

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2000 MERCEDES ML320 WILL STALL SOMETIMES WHEN BRAKING AND TURNING. IT WILL ALSO SOMETIMES SHUTTER WHEN YOU ARE STARTING TO ACCELERATE FROM A STOP. IT HAS CODES P0201 P0202 P0203 P0204 P0206 P1420 P1420 P0446-37 P0443 AND P1400. ANY HELP ON WHERE THE PLACE TO START DIAGNOSING THE PROBLEM WILL BE APPRECIATED.

Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay.

The first set of codes you have (p0201 through P0206) is for fuel injectors 1 through 6 circuit failure.Code P1420 indicates a fault with the air pump switch over valve,code P1400 indicates EGR vacuum transducer fault,code P0443 indicates fault with purge control valve,code P0446 indicates fault with canister shut off valve.

If all of these codes came up and issues occurred at the same time it is very rare for all of these components to fail at the same time.This indicates that there is either an engine wiring harness fault leading from all of these components to the engine computer (this can be common if wiring is breaking/coming apart or shorting out) or that the engine computer itself is at fault internally needing replaced.I have seen both occur here.

I would have the engine wiring harness checked over leading to the computer for any issues.If no issues are found then I suspect the engine computer itself needs replaced.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service,your 5 star rating is appreciated.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.

Thanks Pete

Customer: replied 1 month ago.
i don't see any damage to the wiring so can you please give me the procedure in testing the ecm

I will post the procedure below for code P0201 which will help lead to see if the ME (engine computer) is at fault.This needs followed to locate the cause here.

Y62y1 (Fuel Injector Cylinder 1)

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

1 Test Actuation of Component Y62y1 (Cylinder 1 Injector)

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 Check Actual Value Y62y1 (Cylinder 1 Injector)

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. [3...5] and when engine is idling.
- 80 °C The value is ms at a coolant temperature of approx. [13...22] 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 P0201?
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 **

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

Test requirement
- Fault code present P0201

Test sequence
- Switch off ignition.
- Connect socket box to component N3/10 (ME-SFI control module).
- (E.25) 81 <--> 2 (A.2)

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 [13...16] 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 **

4 Inspect Component Y62y1 (Cylinder 1 Injector) For Leaks

Test sequence
- Switch off ignition.
- Remove fuel rail together with component Y62 (Fuel injectors).
- Connect socket box to component N3/10 (ME-SFI control module).
- (A.3) 3 <--> 33 (D.1)
- 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 **

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

https://www.dropbox.com/s/o6p1c64ulwmcg1e/in-10-18.gif?dl=0

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

https://www.dropbox.com/s/ivb1tufnyf4uggp/inj-10-18.gif?dl=0

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

https://www.dropbox.com/s/6f6i1f1ephm8td8/inje-10-18.gif?dl=0

Test sequence
- Switch off ignition.
- Remove fuel rail together with component Y62 (Fuel injectors).
- Connect socket box to component N3/10 (ME-SFI control module).
- Insert bridge.:
- (A.3) 3 <--> 33 (D.1)
- Switch on ignition.
- Note: Component M3 (fuel pump) runs.
- Hold fuel injectors one after another in a vessel and briefly operate manually with shop-made test cable set at sockets 3 (-) and 2 (+) of the 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 **

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

Test sequence
- Switch off ignition.
- Connection Measuring system
- (E.25) 81 <--> 2 (A.2)
- 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)

If you do not have the correct test equipment to do this testing this will need done by someone that does have this test equipment.

Let me know if you need anything else and feel free to rate my help here as this is how I receive credit for my time.Your 5 star rating is appreciated

Thanks Pete

Pete and 2 other Mercedes Specialists are ready to help you
Customer: replied 1 month ago.
The problem was the piece of metal that holds the battery in place wasn't bolted down so the positive wire on the battery was coming into contact with it and shorting out. Thank you for the help

Your welcome