Page 315 - Foton Workshop Manual - Tunland (AT)

DIAGNOSTICS - ENGINE CONTROL SYSTEM 04-169

DTC inspection
DTC DTC definition Trouble location
conditions
Atmospheric pressure
sensor circuit voltage
P221 is above normal or • Atmospheric
short circuit to high pressure sensor 04
voltage power supply • The circuit of the

Atmospheric pressure • When the key wiring harness,
sensor circuit voltage switch is in ON connector or sensor
P222 is below normal or position, the is open
short circuit to low diagnosis continues • The signal wire is
voltage power supply to run short to the sensor
power or battery
Ambient air density -
voltage
data is valid but
• ECM
P1943 above normal
operating range -
lowest 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 atmospheric pressure sensor?

Is the inspection result normal?
YES>To step 2.

NO>Intermittent trouble exists.

2 . Check atmospheric pressure sensor power supply circuit
(a) Ignition switch: OFF.
(b) Disconnect the battery negative cable.
(c) Disconnect the atmospheric pressure sensor connector E20.
(d) Connect the battery negative cable.

Page 315