Suzuki WagonR+ RB310, Service Manual

Page: 2368 / 3086

ENGINE DIAGNOSIS 6-9
ON-BOARD DIAGNOSTIC SYSTEM
(VEHICLE WITHOUT EGR VALVE)
ECM diagnosis troubles which may occur in the area including the
following parts when the ignition switch is ON and the engine is run-
ning, and indicates the result by turning on or flashing malfunction
indicator lamp (1).
!
Heated oxygen sensor
!
ECT sensor
!
TP sensor
!
IAT sensor
!
MAP sensor
!
CMP sensor
!
CKP sensor
!
VSS
!
CPU (Central Processing Unit) of ECM
ECM and malfunction indicator lamp (1) operate as follows.
!
Malfunction indicator lamp (1) lights when the ignition switch is
turned ON (but the engine at stop) with the diagnosis switch termi-
nal ungrounded regardless of the condition of Electronic Fuel In-
jection system. This is only to check the malfunction indicator
lamp (1) bulb and its circuit.
!
If the above areas of Electronic Fuel Injection system is free from
any trouble after the engine start (while engine is running), mal-
function indicator lamp (1) turns OFF.
!
When ECM detects a trouble which has occurred in the above
areas, it makes malfunction indicator lamp (1) turn ON while the
engine is running to warn the driver of such occurrence of trouble
and at the same time it stores the trouble area in ECM back-up
memory. (The memory is kept as it is even if the trouble was only
temporary and disappeared immediately. And it is not erased un-
less the power to ECM is shut off for specified time below.)
ECM also indicates trouble area in memory by means of flashing
of malfunction indicator lamp (1) at the time of inspection. (i.e.
when diagnosis switch terminal (2) is grounded and ignition
switch is turned ON.)
NOTE:
!
When a trouble occurs in the above areas and disappears
soon while the diagnosis switch terminal is ungrounded and
the engine is running, malfunction indicator lamp (1) lights
and remains ON as long as the trouble exists but it turns OFF
when the normal condition is restored.
!
Time required to erase diagnostic trouble code memory thor-
oughly varies depending on ambient temperature as follows.
AMBIENT
TEMPERATURE
TIME TO CUT POWER
TO ECM
Over 0
"
C (32
"
F) 60 sec. or longer
Under 0
"
C (32
"
F)
Not specifiable.
Select a place with higher than
0
"
C (32
"
F) temperature.