Page 417 - Foton Workshop Manual - Tunland (AT)

DIAGNOSTICS - ENGINE CONTROL SYSTEM 04-271

DTC inspection
DTC DTC definition Trouble location
conditions
Postprocessing diesel
• The active • Postprocessing
oxidation converter
regeneration of the diesel oxidation
system efficiency -
diesel particulate catalyst
P1691 data is valid but filter must be • Exhaust system 04
above normal
performed before • ECM and its
operating range -
the diagnosis runs. harness
medium severity level

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 diesel oxidation converter
missing circuit?

Is the inspection result normal?
YES>To step 2.
NO>Intermittent trouble exists.

2 . Check the mechanical systems of postprocessing diesel oxidation catalyst.
(a) Check whether there are carbon deposits blocked at the front of the catalytic converter
for the postprocessing diesel oxidation catalyst.
(b) Check whether there are engine oil or fuel contamination in the postprocessing diesel
oxidation catalyst.
(c) Check whether the postprocessing diesel oxidation catalyst is cracked or contaminated.
(d) Check whether there is fault in postprocessing fuel injection system.
(e) Check whether there is leakage of exhaust system between turbocharger and diesel
oxidation catalyst.

Is the inspection result normal?
YES>To step 3.
NO>Check the fault location.

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