Page 424 - Foton Workshop Manual - Tunland (AT)

04-278 DIAGNOSTICS - ENGINE CONTROL SYSTEM

DTC inspection
DTC DTC definition Trouble location
conditions
• When the engine
• Postprocessing
runs and the
Postprocessing diesel exhaust flow is DPF differential
particulate filter pressure sensor
04 P1993 higher than the
missing - the • Postprocessing
minimum, the
condition exists DPF
diagnosis continues
• ECM
to run.
• Postprocessing
diesel particulate
Postprocessing DPF • When the engine filter
differential pressure -
speed is higher • Postprocessing
data is valid but
P2639 than 500rpm, the diesel particulate
above normal diagnosis continues filter differential
operating range -
to run. pressure sensor
lowest severity level
and its harness
• ECM

• This diagnosis can
• Postprocessing
only be performed
Postprocessing DPF DPF
after the active
differential pressure - regeneration of the • Postprocessing
data is valid but diesel particulate
P3168 postprocessing
above normal filter differential
diesel particulate
operating range - pressure sensor
filter has been
highest severity level and its harness
successfully
• ECM
completed.

Diagnosis Procedure
NOTICE

• To implement the following steps, ensure that ECM is grounded properly.
• Before conducting electric diagnosis, do refer to the reference circuit diagram
and the element information.
• Before conducting measurement, check the pins of connectors for rupture,
looseness and rust, and ensure that the pins are contacted properly.
• If the connection is good, check the sensor signal voltage when moving the
connector and harness. If a fault occurs, the voltage display on the diagnostic
instrument will change.

1 . DTC inspection
(a) Ignition switch: OFF.
(b) Connect the diagnostic apparatus.
(c) Use the diagnostic apparatus, read the fault code.
(d) Confirm whether there is fault code related to postprocessing DPF differential pressure
sensor circuit?

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