1999 SUZUKI GRAND VITARA Code check

YH4
GRAND
VITARA
1. Coil antenna
2. Ignition key
3. Immobilizer control module
4. Data link connector (DLC)
5. Immobilizer diagnostic coupler Ignition key
Transponder
code
Immobilizer
Control
ModuleECM/
PCM
8G-2 IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED)
GENERAL DESCRIPTION
The immobilizer control system designed to prevent vehicle burglar consists of following components.

Engine control module (ECM) / Powertrain control module (PCM)

Immobilizer control module

Ignition key (with built-in transponder)

Coil antenna
Operation of this system is as follows.
(1) Each ignition key has its own code (Transponder code) stored in memory. When the ignition switch is turned
ON, Immobilizer Control Module tries to read the Transponder code through the coil antenna installed to the
steering lock assembly.
(2) Immobilizer Control Module compares the Transponder code read in (1) and that registered in Immobilizer Con-
trol Module and checks if they match.
(3) When it is confirmed that two Transponder codes match each other as described above, Immobilizer Control
Module and ECM / PCM check if ECM/Immobilizer Control Module codes registered in them respectively match.
(4) Only when it is confirmed that ECM/Immobilizer Control Module codes match, the engine starts running. If
Transponder codes in Step (2) or ECM/Immobilizer Control Module codes in Step (3) do not match, ECM / PCM
will stop operation of the injector and ignition of spark plug.

YH4
GRAND
VITARA
1. Immobilizer Control Module
8G-4 IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED)
IMMOBILIZER CONTROL MODULE
Immobilizer Control Module is installed to the underside of the
instrument panel at the driver's seat side.
As main functions, Immobilizer Control Module checks matching
not only between the Transponder Code transmitted from the igni-
tion key and that registered in Immobilizer Control Module (Up to
4 different Transponder codes can be registered.) but also between
the ECM/Immobilizer Control Module code transmitted from
ECM / PCM and that registered in Immobilizer Control Module. In
addition, it has an on-board diagnostic system (self-diagnosis func-
tion) which is described in ªOn-Board Diagnostic System (Self-
Diagnosis Function)º in this section.
ECM / PCM
As main functions, ECM / PCM not only checks matching of ECM/
Immobilizer Control Module code but also has an on-board diag-
nostic system (self-diagnosis function) as described in ªOn-Board
Diagnostic System (Self-Diagnosis Function)º in this section.
For installation position of ECM / PCM, refer to Section 6E1 or 6E2.
ON-BOARD DIAGNOSTIC SYSTEM
(SELF-DIAGNOSIS FUNCTION)
Immobilizer Control Module and ECM / PCM diagnose troubles
which may occur in the area including the following parts when the
ignition switch is ON.
ECM /
ECM/Immobilizer Immobilizer
Transponder code
PCM: Control Module Control
Coil antenna
code Module:
ECM/Immobilizer

Serial data link
Control Module code
circuit
Serial data link circuit

ECM / PCM
Immobilizer Control

Module

Ignition signal

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.

YH4
GRAND
VITARA
IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED) 8G-7
[INTERMITTENT TROUBLES]


There are cases where output of diagnostic output terminal
and / or malfunction indicator lamp indicate a diagnostic trouble
code representing a trouble which occurred only temporarily and
has gone. In such case, it may occur that good parts are replaced
unnecessarily. To prevent such accident, be sure to follow instruc-
tions given below when checking by using ªDiagnostic Flow
Tableº.
* When trouble can be identified, it is not an intermittent one:
Check coil antenna, ignition key, wires and each connection
and if they are all in good condition, substitute a known-good
ECM / PCM and recheck.
* When trouble can not be identified but output of diagnostic out-
put terminal and / or malfunction indicator lamp indicate a
trouble code:
Diagnose trouble by using that code No. and if ignition key, coil
antenna, wires and each connection are all in good condition,
turn OFF ignition switch and then ON.
Then check what malfunction indicator lamp and / or output of diag-
nostic output terminal indicate.
Only when they indicate trouble code again, substitute a known-
good ECM / PCM or Immobilizer Control Module and check again.
If they indicate not trouble code but normal code, it means that an
intermittent trouble did occur and has gone. In this case, check
wires and connections carefully again.


There are cases where output of diagnostic output terminal and/
or Suzuki scan tool indicates a diagnostic trouble code represent-
ing a trouble which occurred only temporarily and has gone. In
such case, it may occur that good parts are replaced unnecessar-
ily. To prevent such accident, be sure to follow instructions given
below when checking by using ªDiagnostic Flow Tableº.
* When trouble can be identified, it is not an intermittent one:
Check coil antenna, ignition key, wires and each connection
and if they are all in good condition, substitute a known-good
ECM / PCM and recheck.
* When trouble can not be identified but output of diagnostic out-
put terminal and/or Suzuki scan tool indicates a trouble code:
Diagnose trouble by using that code No. and if ignition key, coil
antenna, wires and each connection are all in good condition,
turn OFF ignition switch and then ON.
Then check what Suzuki scan tool and/or output of diagnostic out-
put terminal indicates.
Only when they indicate trouble code again, substitute a known-
good ECM / PCM or Immobilizer Control Module and check again.
If they indicate not trouble code but normal code, it means that an
intermittent trouble did occur and has gone. In this case, check
wires and connections carefully again.

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.

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.

YH4
GRAND
VITARA
8G-10 IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED)
DIAGNOSTIC FLOW TABLE

STEPACTIONYESNO
11) Check immobilizer indicator lamp
while ignition switch is ON (but without
starting engine). See Fig. 1.
Dose immobilizer indicator lamp flash?Go to Step 3.
If immobilizer indicator lamp
remains ON, go to Step 2.

If immobilizer indicator lamp
remains OFF, go to
ªIMMOBILIZER INDICATOR
LAMP CHECKº in this section.
21) 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 ªIMMOBILIZER
INDICATOR LAMP
CHECKº in this section.Immobilizer control system is in
good condition.
31) 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 4.
41) Check DTC stored in ECM / PCM
referring to ªDIAGNOSTIC TROUBLE
CODE CHECK (ECM / PCM)º in this
section.
Is there any DTC(s) for immobilizer
control system?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.
FIg. 1 for Step 1

YH4
GRAND
VITARA
IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED) 8G-11
1. Immobilizer diagnostic coupler
EXAMPLE :
COIL ANTENNA FAILURE (CODE NO.13)
Voltmeter indicator

NORMAL (No code)
Voltmeter indicatorTIME (sec.)
TIME (sec.) CODE No. 13CODE No. 13CODE No. 13
High
Low
High
Low
1. Monitor coupler
2. Service wire
A: Diagnosis switch
terminal
B: Ground terminal
DIAGNOSTIC TROUBLE CODE (DTC) CHECK
(IMMOBILIZER CONTROL MODULE)
1) Using analog type voltmeter, connect positive probe to diagnos-
tic output terminal and negative probe to ground of immobilizer
diagnostic coupler with ignition switch turned ON.
2) Read deflection of voltmeter indicator which represents DTC as
shown in example below and write it down. For details of DTC,
refer to Immobilizer Control Module side in ªDiagnostic Trouble
Code Tableº.
If voltmeter indicator dose not deflect, go to ªDiagnostic Flow
Table Aº.
NOTE:
If abnormality or malfunction lies in two or more areas, volt-
meter indicates applicable codes three times each.
DIAGNOSTIC TROUBLE CODE (DTC) CHECK (ECM/PCM)
[Not using SUZUKI scan tool] (Vehicle equipped with
monitor coupler)
1) Using service wire, ground diagnostic switch terminal in monitor
coupler.
2) Read DTC from flashing pattern of malfunction indicator lamp as
shown in example below and write it down. For details of DTC,
refer to ECM / PCM side in ªDiagnostic Trouble Code Tableº.
If lamp remains ON, go to ªMalfunction Indicator Lamp Checkº
in Section 6.
NOTE:
If abnormality or malfunction lies in two or more areas, mal-
function indicator lamp indicates applicable codes three
times each.
And flashing of these codes is repeated as long as diagno-
sis terminal is grounded and ignition switch is held at ON
position.