Page 377 - Foton Workshop Manual - Tunland (AT)

DIAGNOSTICS - ENGINE CONTROL SYSTEM 04-231

P1117-SWITCH OFF DURING IGNITION - DATA IS UNSTABLE,

INTERMITTENT OR INCORRECT
Description

1 . The engine control module (ECM) obtains a stable voltage through the switch-free
battery lead connected directly to the battery positive (+) terminal. When the
04
vehicle key switch goes to the ON position, the engine control module (ECM)
receives the input voltage of the switch battery through the vehicle key switch
wire.

DTC inspection
DTC DTC definition Trouble location
conditions
Power off during • When the key • Battery
ignition - data is switch is in ON • Ignition switch and
P1117 unstable, intermittent position, the its wiring harness
or incorrect DTC diagnosis continues • ECM
inspection conditions to run.

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 power off during ignition?

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

NO>Intermittent trouble exists.

2 . Check the battery connecting harness
(a) Ignition switch: OFF.
(b) Check whether the battery connecting harness is normal.

Is the inspection result normal?
YES>To step 3.

Page 377