The ECM will gradually close the Exhaust Back
Pressure Regulator (EBPR) to establish a desired
cylinder head pressure differential. If the target
pressure differential is not achieved, an error
identifier will be displayed, indicating that the EGR
intake pressure is not responding.
If the pressure differential is achieved, the test will
wait for the DPF intake temperature to stabilize. The
test will then check if the DPF intake temperature is
above a minimum threshold. If the minimum
temperature threshold is not met, an error identifier
will be displayed to indicate that the DPF intake
temperature is too low.
Aftertreatment Regeneration System Test
Note: This test is only applicable to engines that do
not have a DPF in the aftertreatment system.
Avoid contact with hot surfaces. Exhaust piping
and engine components become hot during en-
gine operation and cool slowly after engine shut-
down. Any contact with hot surfaces can cause
severe burns.
This test must be run with the engine running and the
machine/engine out of a working mode. The engine
must be warmed up to a minimum coolant
temperature. Once the coolant temperature
conditions are met, a pop-up screen will advise that
the engine speed will be automatically increased
after the warning is accepted.
Once the pre-conditions are met (no relevant active
diagnostics, coolant temp condition met, elevated
speed in range), the system test will begin. The
EBPR valve control logic will determine the
appropriate desired cylinder head pressure
differential. This determination is reached with a
dedicated fueling and injection timing calibration and
should result in the target SCR intake temperature
being met. The test will then wait for the SCR intake
temperature to rise above a minimum pass threshold.
If the minimum temperature threshold is not met, an
error ID will be displayed indicating “SCR Intake
Temperature Too Low” .
Air System Motor Valves Verification Test
The Air System Motor Valve Verification Test will
identify whether the EGR valve, and the EBPR are
working correctly. This test must be run when the
engine speed is zero and the battery voltage is within
an acceptable range. For a 12VDC system, the
service test must only be executed if the battery
voltage is between 9VDC and 16VDC. For a 24VDC
system, the battery voltage must be between 18VDC
and 32VDC. If the battery voltage is outside of these
ranges at any time, the test must be aborted. The test
will also be aborted if a position sensor diagnostic, a
motor short diagnostic, or a motor open circuit
diagnostic become active.
If at any point during the test the engine speed is not
zero, the test will abort. The test moves the valves to
various positions and then checks the position sensor
within each valve to confirm that the valve has
responded correctly. Each valve will be tested in turn,
starting with the EGR valve. If a test threshold is
exceeded or any related diagnostics become active,
the test will abort and generate an error identifier.
Aftertreatment System Functional Test
This test is used to verify that the SCR System is
functioning correctly. The EBPR and elevated engine
speed are used to increase the exhaust gas
temperature. The higher temperature allows the NOx
sensors and SCR system to control active DEF
dosing.
Avoid contact with hot surfaces. Exhaust piping
and engine components become hot during en-
gine operation and cool slowly after engine shut-
down. Any contact with hot surfaces can cause
severe burns.
When the NOx sensors are ready for use, the
sensors control DEF dosing and check that the NOx
conversion efficiency meets the test target value.
The following conditions must be met for the test to
start:
• Coolant at the minimum required temperature
• DEF at the minimum required temperature
• Exhaust gas at the minimum required temperature
• Sufficient DEF in the tank
• No related active diagnostic codes
• Engine speed and load in the required range
458 UENR4469-36
Service
Copyright of Perkins Engine Company Limited. NOT FOR REPRINTING OR RESALE
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