Page 593 of 801

YH4
GRAND
VITARA
0.5TIME (sec.) Ignition switch ON
High Immobilizer
control system
is normal
Immobilizer
control system
is abnormalLow
0.5 0.5 0.5 0.5
High
Low
0.5TIME (sec.) Ignition switch ON
High Immobilizer
control system
is normal
Immobilizer
control system
is abnormalLow
0.5 0.5 0.5 0.5
High
Low
IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED) 8G-5
With the diagnosis switch terminal of monitor coupler for
ECM / PCM not grounded, the ignition switch turned ON (but the en-
gine at stop) and regardless of the condition of the electronic fuel
injection system, ECM / PCM indicates whether a trouble has oc-
curred in the immobilizer control system or not by causing the mal-
function indicator lamp to flash or turn ON.
Malfunction indicator lamp is ON:
No trouble exists in the immobilizer control system.
Malfunction indicator lamp is flashing:
ECM / PCM or Immobilizer Control Module has detected some
trouble in the immobilizer control system.
NOTE:
As soon as the ignition switch is turned ON, ECM / PCM and Im-
mobilizer Control Module diagnose if a trouble has occurred
in the immobilizer control system. While the diagnosis is being
made, the malfunction indicator lamp stays ON and if the diag-
nosis result is ªabnormalº, it immediately changes to flashing
but if the result is ªnormalº, it remains ON. Diagnosis takes
about 3 seconds at maximum.
With the ignition switch turned ON (but the engine at stop) regard-
less of the condition of the electronic fuel injection system,
ECM / PCM indicates whether a trouble has occurred in the immobi-
lizer control system or not by causing the immobilizer indicator lamp
to flash or turn ON.
Immobilizer indicator lamp is ON:
No trouble exists in the immobilizer control system.
Immobilizer indicator lamp is flashing:
ECM / PCM or Immobilizer Control Module has detected some
trouble in the immobilizer control system.
NOTE:
As soon as the ignition switch is turned ON, ECM / PCM and Im-
mobilizer Control Module diagnose if a trouble has occurred
in the immobilizer control system. While the diagnosis is being
made, the Immobilizer indicator lamp stays ON and if the diag-
nosis result is ªabnormalº, it immediately changes to flashing
but if the result is ªnormalº, it remains ON. Diagnosis takes
about 3 seconds at maximum.
When ECM / PCM and Immobilizer Control Module detects a
trouble which has occurred in the above areas, it stores DTC corre-
sponding to the exact trouble area in ECM / PCM and Immobilizer
Control Module memory.
DTCs stored in memory of each controller (Immobilizer Control
Module and ECM / PCM) can be read by using the procedure de-
scribed in ªDIAGNOSTIC TROUBLE CODE CHECK (IMMOBILIZ-
ER CONTROL MODULE)º and ªDIAGNOSTIC TROUBLE CODE
CHECK (ECM / PCM)º in this section.
Page 594 of 801

YH4
GRAND
VITARA
8G-6 IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED)
1. Immobilizer diagnostic coupler
DIAGNOSIS
ECM / PCM and Immobilizer Control Module have on-board diag-
nostic system (a system self-diagnosis function) as described pre-
viously.
Investigate where the trouble is by referring to ªDiagnostic Flow
Tableº and ªDiagnostic Trouble Code Tableº on later pages.
PRECAUTIONS IN DIAGNOSING TROUBLES
[PRECAUTIONS IN IDENTIFYING DIAGNOSTIC TROUBLE CODE]
ECM / PCM
Before identifying diagnostic trouble code indicated by malfunc-
tion indicator lamp, don't disconnect couplers from ECM / PCM,
battery cable from battery, ECM / PCM ground wire harness from
engine.
Such disconnection will clear trouble codes for electronic fuel in-
jection system stored in memory of ECM / PCM.
If abnormality or malfunction lies in two or more areas, malfunc-
tion indicator lamp indicates applicable codes three times each.
And flashing of these codes is repeated as long as diagnosis ter-
minal is grounded and ignition switch is held at ON position.
When ECM / PCM detects a trouble in both electronic fuel injec-
tion system and immobilizer control system, malfunction indicator
lamp indicates trouble codes of both systems alternately while the
ignition switch is turned ON and the diagnosis terminal is
grounded.
Take a note of diagnostic trouble code indicated first.
Before identifying diagnostic trouble code indicated through Su-
zuki scan tool, don't disconnect couplers from ECM / PCM, bat-
tery cable from battery, ECM / PCM ground wire harness from en-
gine.
Such disconnection will clear trouble codes for electronic fuel in-
jection system stored in memory of ECM / PCM.
Take a note of diagnostic trouble code indicated first.
Immobilizer Control Module
Take a note of diagnostic trouble code indicated first.
Page 596 of 801
![SUZUKI GRAND VITARA 2000 2.G Service Workshop Manual YH4
GRAND
VITARA
8G-8 IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED)
[NOTES ON SYSTEM CIRCUIT INSPECTION]
Refer to ªPrecautions for Electrical Circuit Serviceº and ªIntermit-
tents and Poor Connectionº SUZUKI GRAND VITARA 2000 2.G Service Workshop Manual YH4
GRAND
VITARA
8G-8 IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED)
[NOTES ON SYSTEM CIRCUIT INSPECTION]
Refer to ªPrecautions for Electrical Circuit Serviceº and ªIntermit-
tents and Poor Connectionº](/manual-img/20/7582/w960_7582-595.png)
YH4
GRAND
VITARA
8G-8 IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED)
[NOTES ON SYSTEM CIRCUIT INSPECTION]
Refer to ªPrecautions for Electrical Circuit Serviceº and ªIntermit-
tents and Poor Connectionº in Section 0A.
[Precaution after replacing ECM / PCM or Immobilizer Control Mod-
ule]
When ECM / PCM was replaced, including when replaced be-
cause rechecking by using a known-good ECM / PCM was neces-
sary during trouble diagnosis, the ECM/Immobilizer Control Mod-
ule code must be registered in ECM / PCM and Immobilizer
Control Module by performing procedure described in ªProce-
dure after ECM / PCM Replacementº on p. 8G-27. If it is not regis-
tered, the engine would not start and accurate trouble diagnosis
would not be assured.
When Immobilizer Control Module was replaced, including when
replaced because rechecking by using a known-good Immobiliz-
er Control Module was necessary during trouble diagnosis, the
Transponder code and ECM/Immobilizer Control Module code
must be registered in Immobilizer Control Module and ECM/Im-
mobilizer Control Module code in ECM / PCM by performing pro-
cedure described in ªProcedure after Immobilizer Control Module
Replacementº on p. 8G-26. If they are not registered, the engine
would not start and accurate trouble diagnosis would not be as-
sured.
Page 597 of 801

YH4
GRAND
VITARA
IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED) 8G-9
Fig. 1 for Step 1 Fig. 2 for Step 1 Fig. 3 for Step 2
1. Monitor coupler
2. Service wire
A: Diagnosis switch terminal
B: Ground terminal
Fig. 4 for Step 3
ªCHECK ENGINEº light
0.5
ON
OFF
TIME (sec.)
DIAGNOSTIC FLOW TABLE
STEPACTIONYESNO
11) Make sure that diagnosis switch
terminal in monitor coupler is not
grounded by service wire. See Fig. 1.
2) Check malfunction indicator lamp
while ignition switch is ON (but without
starting engine). See Fig. 2.
Dose malfunction indicator lamp flash?Go to Step 3.If malfunction indicator lamp
remains ON, go to Step 2.
If malfunction indicator lamp
remains OFF, go to
ªMALFUNCTION INDICATOR
LAMP CHECKº in Section 6.
21) Using service wire, ground diagnosis
switch terminal in monitor coupler.
See Fig. 3.
Dose malfunction indicator lamp flash?Immobilizer control
system is in good
condition.Go to ªMALFUNCTION
INDICATOR LAMP CHECKº in
Section 6.
3Dose malfunction indicator lamp flash as
Fig. 4?Go to Step 4.Go to ªMALFUNCTION
INDICATOR LAMP CHECKº in
Section 6.
41) Check DTC stored in immobilizer
control module referring to
ªDIAGNOSTIC TROUBLE CODE
CHECK (IMMOBILIZER CONTROL
MODULE)º in this section.
Is there any DTC(s)?Go to flow table for
DTC No.Go to Step 5.
51) Check DTC stored in ECM/PCM
referring to ªDIAGNOSTIC TROUBLE
CODE CHECK (ECM / PCM)º in this
section.
Is there any DTC(s)?Go to flow table for
DTC No.Substitute a known-good ECM/
PCM and recheck.
NOTE:
After replacing with a known-
good ECM/PCM, register
ECM / Immobilizer Control
Module code in ECM/PCM by
performing procedure described
in ªProcedure after ECM/PCM
Replacementº section.