Page 958 - Workshop Manual - Tunland (2017)

04-272 DIAGNOSTICS - ENGINE CONTROL SYSTEM

04 DTC inspection
DTC DTC definition Trouble location
conditions

Postprecessing diesel • Postprocessing
particulate filter DOC temperature
P4259 temperature sensor sensor module and
module - root cause its harness
unknow. • ECM

Diagnosis Procedure

CAUTION

• 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 preheating diesel oxidation
converter inlet temperature sensor circuit?

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

2 . Check DPF temperature sensor circuit
(a) Ignition switch: OFF.
(b) Disconnect the battery negative cable.
(c) Disconnect DPF temperature sensor connector Q01.
(d) Connect the battery negative cable.
(e) Ignition switch: ON.