OM654 Engine Cranks with No Start /
Insufficient High-Pressure Fuel Build-Up
Topic number

LI07.16-N-080732

Version

1

Function group

07.16 - Diesel injection system common rail

Date

6/18/26

Validity

OM654 Sprinter 907

Reason for change

Complaint
The customer reports that the engine cranks but does not start, or only starts after extended cranking. A check engine
light may be present, and fault codes P300616 (The fuel pressure in the system is too low) and/or P300617 (The fuel
pressure in the system is too low) may be stored, along with other fuel pressure-related fault codes.

Cause
Insufficient high-pressure fuel build-up during engine cranking. The fuel system does not achieve the required rail
pressure of >120 bar, preventing engine start.
This condition may be caused by internal leakage within the fuel injection system, inadequate fuel supply from the
low-pressure circuit, or a malfunction of the high-pressure fuel pump.

Remedy
1. Verify high-pressure fuel rail pressure during engine cranking using XENTRY actual values.
• Evaluate the actual value “The starter turns and the combustion engine does not start” and monitor high-pressure fuel rail pressure during cranking.
(See attachment: XENTRY actual values – rail pressure not reaching >120 bar)
• The system must achieve a minimum of >120 bar in order to enable engine start.
→ If the specified rail pressure is not achieved, perform the following checks:
2. Check low-pressure fuel supply
• Verify fuel quality (color, clarity, separation, contamination)
• Inspect fuel tank, fuel filter, and low-pressure fuel pump for debris, restriction, or damage
• Measure low-pressure fuel supply before and after the fuel filter and confirm values are within specification
• Perform a fuel volume test at the high-pressure pump inlet to ensure adequate delivery
• Verify that the injector leak line is installed correctly, remains unmodified, and is not restricted or kinked
22.06.2026 15:51
© Copyright Mercedes-Benz AG

CCUSHWA

Page 1 / 3

→ If low-pressure fuel supply is not within specification:
Repair as necessary and recheck high-pressure fuel build-up
3. Check for internal leakage within the fuel injection system
• Perform a fuel injector leak/return test using XENTRY
• Evaluate injector leak-back during cranking
NOTE:
If the combustion engine does not start, perform the test by cranking the engine 3–4 times for approximately 15 seconds each, instead of allowing the engine to run for approximately 60 seconds
→ If injector leakage is present:
Replace the affected injector(s) and perform injector teach-in
4. Check high-pressure fuel system
• If no leakage is identified and low-pressure supply is sufficient, evaluate high-pressure fuel generation
→ If high-pressure fuel system does not generate sufficient pressure:
Replace the high-pressure fuel pump
5. Final verification
• Verify that rail pressure exceeds >120 bar during cranking
• Confirm the engine starts normally without extended crank
• Clear fault codes and perform final validation
Note:
All work must be carried out in accordance with applicable WIS procedures. Ensure proper cleanliness when working
on the fuel system and complete all required teach-in processes.

Attachments
File

Description

Rail Pressure.png

Rail pressure not reaching >120 bar

22.06.2026 15:51
© Copyright Mercedes-Benz AG

CCUSHWA

Page 2 / 3

Disclaimer
NOTE: The information contained in this document is intended for use by trained, professional technicians with the
knowledge to properly and safely perform diagnosis and repairs on Mercedes-Benz vehicles, using Mercedes-Benz
approved tools and equipment. It informs service technicians about conditions that could occur in certain vehicles and
provides information that could assist in proper vehicle diagnosis, service, or repair. It does not indicate that a defect
is present in any vehicle referenced in this document nor does it imply warranty coverage. DO NOT assume that a
symptom or condition, or a described cause of a symptom or condition, affects any particular vehicle or groups of vehicles, or that a described repair applies to any particular vehicle or groups of vehicles. There can be multiple causes
resulting in the same or similar symptoms or conditions described in this document, and trained professional service
technicians must use their diagnostic skills to make evaluations on a case-by-case basis. The information contained
in this document does not guarantee warranty coverage nor does it extend the vehicle’s warranty in any way.

Symptoms
Power generation > Fuel system > Fuel pump > Malfunction
Power generation > Engine management > Indicator lamp > Engine diagnosis > lit
Power generation > Engine management > Engine start/stop > Long starting time
Power generation > Engine management > Engine start/stop > Does not start
Power generation > Engine management > Function > Malfunction

Operation numbers/damage codes
Op. no.

Operation text

22.06.2026 15:51
© Copyright Mercedes-Benz AG

Time

CCUSHWA

Damage
code

Note

Page 3 / 3