Volvo Symptom D12D US02 Service Manual page 53

Group 20
Sudden Loss of Power
Sudden power loss may be caused by:
•
Failure in a component or system causing a lack of fuel
or air, or intake/exhaust restrictions.
•
Poor fuel quality.
•
Mechanical problems in internal engine components.
•
Factors monitored by the engine control system,
including sensor faults, high coolant temperature, or
high engine load.
•
EGR valve or reed valve faults.
•
VG Turbocharger malfunction (D16D).
The following checks should be performed in order until
the fault is found. These checks also can help exclude
components with no faults or malfunctions. The amount
Gradual Loss of Power
Gradual power loss may be caused by:
•
Gradual failure in a component or system causing
irregular combustion.
•
Air intake restrictions.
•
Exhaust restrictions.
•
EGR or reed valve faults.
The following checks should be performed in order until
the fault is found. These checks also can help exclude
components with no faults or malfunctions. The amount
and sequence of checks depend on results from Basic
Checks (including active or inactive fault codes noted),
D
and sequence of checks depend on results from Basic
Checks (including active or inactive fault codes noted),
vehicle conditions, vehicle service and repair history,
other symptoms, and information from the driver.
•
"Step 1: Fault Code Readings" page 51
•
"Step 2: Visual Inspection (System Checks)" page 52
•
"Step 3: VCADS Pro Tests" page 53
•
"Step 4: Component and Function Checks" page 54
"Low Power Output, Fault Tracing" page 47
vehicle conditions, vehicle service and repair history,
other symptoms, and information from the driver.
•
"Step 1: Fault Code Readings" page 55
•
"Step 2: Visual Inspection (System Checks)" page 56
•
"Step 3: VCADS Pro Tests" page 56
•
"Step 4: Component and Function Checks" page 57
"Low Power Output, Fault Tracing" page 47
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