1999 SUZUKI GRAND VITARA ecm

YH4
GRAND
VITARA
8G-18 IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED)
12
3
4
1. Main fuse
2. Main relay
3. Immobilizer
Control Module
4. Coil antenna
5. To ECM / PCM 5 (a)
(f)(k)
(I)
DTC13 NO TRANSPONDER CODE TRANSMITTED OR COIL ANTENNA
OPENED/SHORTED
DESCRIPTION:
Immobilizer Control Module energizes the coil antenna when the ignition switch is ON and reads Transponder code
from the ignition key. When Immobilizer Control Module cannot read Transponder code from the ignition key even
when the coil antenna is energized, this DTC is set.
INSPECTION:
STEPACTIONYESNO
1Does ignition key being used have built-in trans-
ponder? (See Fig. 1)Go to Step 2.Replace ignition key with built-in trans-
ponder and follow ªDIAGNOSTIC
FLOW TABLEº again.
21) Disconnect coil antenna coupler with ignition
switch turned OFF.
2) Is there continuity between coil antenna cou-
pler terminals A and B?
(See Fig. 2)Go to Step 3.Coil antenna open.
3Measure resistance between terminals of coil an-
tenna coupler and body ground. (See Fig. 3)
Is it
(infinity)
?Go to Step 4.Coil antenna shorted to ground.
41) With coil antenna coupler disconnected, dis-
connect Immobilizer Control Module coupler.
2) Measure resistance between coil antenna ter-
minals of Immobilizer Control Module coupler.
(See Fig. 4)
Is it
(infinity)
?Go to Step 5.ª(k)º wire shorted to ª(l)ºwire.
5Measure resistance between terminal A1 of Im-
mobilizer Control Module coupler and body
ground.
(See Fig. 5)
Is it
(infinity)
?Go to Step 6.ª(k)º wire shorted to ground.
6Measure resistance between terminal A2 of Im-
mobilizer Control Module coupler and body
ground. (See Fig. 6)
Is it
(infinity)
?Go to Step 7.ª(I)º wire shorted to ground.
71) Connect coil antenna coupler.
2) Is there continuity between Immobilizer Con-
trol Module coupler terminals A1 and A2?
(See Fig. 7)Go to Step 8.
ª(k)º or ª(I)º wire open.

Poor coil antenna-to-coupler.

YH4
GRAND
VITARA
IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED) 8G-19
DTC13 NO TRANSPONDER CODE TRANSMITTED OR
COIL ANTENNA OPENED/SHORTED
(CONTINUED)
STEPACTIONYESNO
8Poor A1 or A2 connection.
1) If connections are OK, connect
Immobilizer Control Module
coupler and substitute a known-
good coil antenna.
2) Is DTC 13 also indicated with
ignition switch turned ON?Go to Step 9.Faulty coil antenna.
9Is DTC 13 still indicated even when
another ignition key (with built-in
transponder) for that vehicle used?Substitute a known-good Immobilizer
Control Module and recheck.
NOTE:
After replacing with a known-good
Immobilizer Control Module, register
ECM/Immobilizer Control Module code
in ECM / PCM and Transponder code
and ECM/Immobilizer Control Module
code in Immobilizer Control Module by
performing procedure described in
ªProcedure after Immobilizer Control
Module Replacementº section.Faulty ignition key.
1. Coil antenna
coupler
1
1. Coil antenna
coupler
1
A
B
Fig. 1 for Step 1
Ignition key with built-in
transponder
Fig. 2 for Step 2 Fig. 3 for Step 3
Fig. 4 for Step 4
Fig. 5 for Step 5 Fig. 6 for Step 6
1. Immobilizer Control
Module coupler1
A1
A2
A1
1
1. Immobilizer Control
Module coupler
1. Immobilizer Control
Module couplerA21
Fig. 7 for Step 7
1. Immobilizer Control Module couplerA1
1 A2

YH4
GRAND
VITARA
8G-20 IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED)
DTC21 ECM/IMMOBILIZER CONTROL MODULE CODE NOT MATCHED
(IMMOBILIZER CONTROL MODULE SIDE)
DTC81 ECM/IMMOBILIZER CONTROL MODULE CODE NOT MATCHED
(P1623) (ECM / PCM SIDE)
DTC84 ECM/IMMOBILIZER CONTROL MODULE CODE NOT REGISTERED
(P1620)
DESCRIPTION:

DTC21
Immobilizer Control Module checks if ECM/Immobilizer Control Module code transmitted from ECM / PCM and
that registered in Immobilizer Control Module match when ignition switch is ON. If they do not, this DTC is set.

DTC81 (P1623)
ECM / PCM checks if ECM/Immobilizer Control Module code transmitted from Immobilizer Control Module and
that registered in ECM / PCM match when ignition switch is ON. If they do not, this DTC is set.

DTC84 (P1620)
ECM / PCM checks if code transmitted from Immobilizer Control Module and that registered in ECM / PCM match
when ignition switch is ON. If there is no ECM/Immobilizer Control Module code registered in ECM / PCM, this
DTC is set.
INSPECTION:
Perform procedure described in ªProcedure after ECM / PCM Replacementº section.

YH4
GRAND
VITARA
IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED) 8G-21
12
3
1. Main fuse
2. Ignition switch
3. Immobilizer
Control Module (g)
A4
DTC22 IGNITION SWITCH CIRCUIT OPEN / SHORT
DESCRIPTION:
Immobilizer Control Module monitors ignition signal when the ignition switch is ON. This DTC is set when no ignition
signal input is detected by Immobilizer Control Module.
INSPECTION:
STEPACTIONYESNO
1Check voltage between Immobilizer
Control Module coupler terminal A4
and body ground with ignition
switch turned ON.
(See Fig.1)
Is it 10 ± 14V?Poor A4 terminal connection.
If connection is OK, substitute a
known-good Immobilizer Control
Module and recheck.
NOTE:
After replacing with a know-good
Immobilizer Control Module,
register ECM/Immobilizer Control
Module code in ECM / PCM and
Transponder code and ECM/
Immobilizer Control Module code
in Immobilizer Control Module by
performing procedure described
in ªProcedure after Immobilizer
Control Module Replacementº
section.ª(g)º wire open or short.
Fig. 1 for Step 1
1
A4
1. Immobilizer Control Module

YH4
GRAND
VITARA
8G-22 IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED)
A812
To SDM (if equipped with AIRBAG)
To data link connector (DLC)1. Immobilizer Control Module
2. ECM / PCM (j) (i)
(i)
(i)
DTC23 NO ECM/IMMOBILIZER CONTROL MODULE CODE TRANSMITTED
FROM ECM/PCM OR DLC CIRCUIT OPENED/SHORTED
DTC83 NO ECM/IMMOBILIZER CONTROL MODULE CODE TRANSMITTED
(P1621) FROM IMMOBILIZER CONTROL MODULE OR DLC CIRCUIT
OPENED/SHORTED
DESCRIPTION
When the ignition switch is ON, Immobilizer Control Module requests ECM / PCM and ECM / PCM requests Immobi-
lizer Control Module to transmit ECM/Immobilizer Control Module code. If ECM/Immobilizer Control Module code
is not transmitted from ECM / PCM or Immobilizer Control Module, Immobilizer Control Module sets DTC23 and
ECM / PCM sets DTC83 (P1621).
INSPECTION:
STEPACTIONYESNO
1Check voltage between
Immobilizer Control Mod-
ule coupler terminal A8
and body ground with igni-
tion switch turned ON.
Is it 4 ± 5V?Go to Step 2.ª(i)º or ª(j)º wire
short.
21) Disconnect ECM /
PCM coupler with igni-
tion switch turned
OFF.
2) Is there continuity be-
tween Immobilizer
Control Module cou-
pler terminal A8 and
Data link connector
terminal of ECM / PCM
coupler? (For posi-
tions of Data link con-
nector terminal of
ECM / PCM coupler,
refer to Section 6E1 or
6E2.)Poor A8 connection (Immobilizer Control Module) or
Poor Data link connector terminal connection (ECM /
PCM). If connections are OK, substitute a known-good
ECM / PCM or Immobilizer Control Module and re-
check.
NOTE :

After replacing with a known-good ECM / PCM,
register ECM/Immobilizer Control Module code
in ECM / PCM by performing procedure de-
scribed in ªProcedure after ECM / PCM Replace-
mentº section.

After replacing with a known-good Immobilizer
Control Module, register ECM/Immobilizer Control
Module code in ECM / PCM and Transponder code
and ECM/Immobilizer Control Module code in Im-
mobilizer Control Module by performing proce-
dure described in ªProcedure after Immobilizer
Control Module Replacementº section.ª(i)º or ª(j)º wire be-
tween Immobilizer
Control Module and
ECM / PCM open.
Fig. 1 for step 1
1
A8
1. Immobilizer Control Module
1. Immobilizer Control Module coupler disconnected1
A8Connect to Data link connector terminal
of ECM / PCM coupler disconnected
Fig. 2 for step 2

YH4
GRAND
VITARA
IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED) 8G-23
DTC82 (P1622) FAULT IN ECM / PCM
DESCRIPTION:
This DTC is set when an internal fault is detected in ECM / PCM.
INSPECTION:
STEPACTIONYESNO
11) Ignition switch OFF.
2) Disconnect connectors from
ECM / PCM.
3) Check for proper connection
to ECM / PCM at all terminals.
Are they in good condition?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.Repair or replace.

YH4
GRAND
VITARA
8G-24 IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED)
1
2
3
1
2
1. Immobilizer Control Module
2. Immobilizer Control Module Coupler
3. Body ground
INSPECTION OF ECM / PCM, IMMOBILIZER
CONTROL MODULE AND ITS CIRCUIT
ECM / PCM, Immobilizer Control Module and its circuit can be
checked at ECM / PCM wiring couplers and Immobilizer Control
Module wiring coupler by measuring voltage and resistance. De-
scribed here is only inspection of Immobilizer Control Module. For
inspection of ECM / PCM, refer to ªSECTION 6E1 or 6E2º.
CAUTION:
Immobilizer Control Module cannot be checked by itself. It
is strictly prohibited to connect voltmeter or ohmmeter to
Immobilizer Control Module with coupler disconnected
from it.
Voltage Check
1) Remove Immobilizer Control Module from body with ignition
switch OFF, referring to p. 8G-24.
2) Connect Immobilizer Control Module coupler to Immobilizer
Control Module.
3) Check voltage at each terminal of coupler connected.
NOTE:
As each terminal voltage is affected by the battery voltage,
confirm that it is 11 V or more when ignition switch is ON.
TERMINALCIRCUITNORMAL
VOLTAGECONDITION
A1Coil antenna 10 V
A2Coil antenna 20 VIgnition switch ON
A3Power source10 ± 14 V
A4Ignition signal10 ± 14 VIgnition switch ONA4Ignition signal0 ± 0.8 VIgnition switch OFF
A5Diagnosis output0 ± 14 VIgnition switch ONA5Diagnosis output0 VIgnition switch OFF
A6Blank±±
A7Ground±±
A8Data link connector
(Serial data terminal)4 ± 5 VIgnition switch ON
A9
A10Blank±±
NOTE:
When measuring voltage at A1 and A2 terminals with ignition switch turned ON, be sure to turn ignition
switch ON before connecting positive probe of voltmeter to A1 or A2 terminal. If it is not turned ON first,
DTC13 (Diagnostic Trouble Code 13) may be indicated.

YH4
GRAND
VITARA
IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED) 8G-27
1
1. Immobilizer Control Module
1. Steering column lower cover
1. Coil antenna
IMMOBILIZER CONTROL MODULE
Removal
1) Disconnect negative (±) cable at battery.
2) Remove steering column hole cover.
3) Disconnect coupler at Immobilizer Control Module.
4) Remove Immobilizer Control Module.
Installation
Reverse removal procedure for installation.
NOTE:
After replacing Immobilizer Control Module, be sure to register
Transponder code and ECM/Immobilizer Control Module code
in Immobilizer Control Module and ECM/Immobilizer Control
Module code in ECM / PCM by performing procedure described
in ªProcedure after Immobilizer Control Module Replacementº
section.
COIL ANTENNA
Removal
1) Disconnect negative (±) cable at battery.
2) Remove steering column upper and lower cover by removing 3
screws.
3) Remove steering column hole cover.
4) Remove coil antenna.
Installation
For installation, reverse removal procedure.