2000 SUZUKI GRAND VITARA ECM REPLACEMENT

YH4
GRAND
VITARA
7B1-20 AUTOMATIC TRANSMISSION (4 A / T)
PRECAUTION IN DIAGNOSING TROUBLE

Don't disconnect couplers from PCM (ECM), battery cable from battery, PCM ground wire harness from engine
or main fuse before checking the diagnosis information (DTC, freeze frame data, etc.) stored in PCM memory.
Such disconnection will clear memorized information in PCM memory.

Using SUZUKI scan tool (Tech-1), or also generic scan tool for vehicle without monitor connector, the diagnostic
information stored in PCM memory can be checked and cleared as well. Before its use, be sure to read Operator's
(instruction) Manual supplied with it carefully to have good understanding of its functions and usage.

Priorities for diagnosing troubles (Only for vehicle without monitor connector)
If two or more diagnostic trouble codes (DTCs) are stored, proceed to the flow table of the DTC which was de-
tected earliest in the order and follow the instruction in that table.
If no instructions are given, troubleshoot diagnostic trouble codes according to the following priorities.
1. Diagnostic trouble codes (DTCs) other than DTC P0171 / P0172 (Fuel system too lean / too rich) and DTC
P0400 (EGR flow malfunction)
2. DTC P0171 / P0172 (Fuel system too lean / too rich) and DTC P0400 (EGR flow malfunction)

Be sure to read ªPrecautions for Electrical Circuit Serviceº in Section 0A before inspection and observe what is
written there.

PCM replacement
When substituting a known-good PCM, check for following conditions.
Neglecting this check may result in damage to good PCM.
± All relays and actuators have resistance of specified value.
± MAF sensor, MDP sensor, TP sensor and fuel tank pressure sensor are in good condition. Also, the power
circuit of these sensors is not shorted to the ground.

YH4
GRAND
VITARA
8G
IMMOBILIZER CONTROL SYSTEM (IF EQUIPPED) 8G-1
GENERAL DESCRIPTION8G- 2 . . . . . . . . . . . . . .
Ignition Key 8G- 3. . . . . . . . . . . . . . . . . . . . . . . . . .
Coil Antenna 8G- 3. . . . . . . . . . . . . . . . . . . . . . . . .
Immobilizer Control Module 8G- 4. . . . . . . . . . . .
ECM/PCM 8G- 4. . . . . . . . . . . . . . . . . . . . . . . . . . .
On-Board Diagnostic System
(Self-Diagnosis Function) 8G- 4. . . . . . . . . . . . .
DIAGNOSIS8G- 6 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Precautions in Diagnosing Troubles 8G- 6. . . . .
Diagnostic Flow Table with monitor coupler> 8G- 9. . . . . . . . . . . . . . . .
Diagnostic Flow Table equipped with monitor coupler> 8G-10. . . . . . .
Diagnostic Trouble Code Check
(Immobilizer Control Module) 8G-11. . . . . . . .
Diagnostic Trouble Code Check
(ECM / PCM) 8G-11. . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code Table 8G-13. . . . . . . . .
TABLE A DTC is not Output
from Diagnostic Output Terminal 8G-14. . . . . . .
TABLE B Immobilizer Indicator Lamp
Check (Immobilizer Indicator Lamp
does not Light at Ignition Switch ON) 8G-15. . .
TABLE C Immobilizer Indicator Lamp
Check (Immobilizer Indicator Lamp
Remains on after Engine Starts) 8G-16. . . . . . .
DTC11 Transponder Code Not Matched8G-17 . .
DTC31 Transponder Code Not
Registered 8G-17. . . . . . . . . . . . . . . . . . . . . . . . .
DTC12 Fault in Immobilizer
Control Module 8G-17. . . . . . . . . . . . . . . . . . . . . .
DTC13 No Transponder Code Transmitted
or Coil Antenna Opened/Shorted 8G-18. . . . . . DTC21 ECM/Immobilizer Control Module
Code Not Matched (Immobilizer Control
Module Side) 8G-20. . . . . . . . . . . . . . . . . . . . . . .
DTC81 (P1623) ECM/Immobilizer
Control Module Code Not Matched
(ECM/PCM Side) 8G-20. . . . . . . . . . . . . . . . . . . .
DTC84 (P1620) ECM/Immobilizer Control
Module Code Not Registered 8G-20. . . . . . . . .
DTC22 Ignition Switch Circuit Open/Short8G-21 . .
DTC23 No ECM/Immobilizer Control
Module Code Transmitted from ECM/
PCM or DLC Circuit Opened/Shorted8G-22 . . . .
DTC83 (P1621) No ECM/Immobilizer
Control Module Code Transmitted from
Immobilizer Control Module or DLC
Circuit Opened/Shorted 8G-22. . . . . . . . . . . . . .
DTC82 (P1622) Fault in ECM/PCM 8G-23. . . . .
Inspection of ECM/PCM, Immobilizer
Control Module and Its Circuit 8G-24. . . . . . . . .
Voltage Check 8G-24. . . . . . . . . . . . . . . . . . . . .
Resistance Check 8G-25. . . . . . . . . . . . . . . . . .
ON-VEHICLE SERVICE8G-26 . . . . . . . . . . . . . . . .
Precautions in Handling Immobilizer
Control System 8G-26. . . . . . . . . . . . . . . . . . . . .
Immobilizer Control Module 8G-27. . . . . . . . . . . .
Coil Antenna 8G-27. . . . . . . . . . . . . . . . . . . . . . . . .
HOW TO REGISTER IGNITION KEY8G-28 . . . . .
PROCEDURE AFTER IMMOBILIZER
CONTROL MODULE REPLACEMENT8G-29 . .
PROCEDURE AFTER ECM/PCM
REPLACEMENT8G-30 . . . . . . . . . . . . . . . . . . . . . .
SPECIAL TOOLS8G-30 . . . . . . . . . . . . . . . . . . . . . .
SECTION 8G
IMMOBILIZER CONTROL SYSTEM
(IF EQUIPPED)
WARNING:
For vehicles equipped with Supplemental Restraint (Air Bag) System

Service on and around the air bag system components or wiring must be performed only by an autho-
rized SUZUKI dealer. Refer to ªAir Bag System Components and Wiring Location Viewº under ªGener-
al Descriptionº in air bag system section in order to confirm whether you are performing service on
or near the air bag system components or wiring. Please observe all WARNINGS and ªService Precau-
tionsº under ªOn-Vehicle Serviceº in air bag system section before performing service on or around
the air bag system components or wiring. Failure to follow WARNINGS could result in unintentional
activation of the system or could render the system inoperative. Either of these two conditions may
result in severe injury.

Technical service work must be started at least 90 seconds after the ignition switch is turned to the
ªLOCKº position and the negative cable is disconnected from the battery. Otherwise, the system may
be activated by reserve energy in the Sensing and Diagnostic Module (SDM).
CONTENTS

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-17
DTC11 TRANSPONDER CODE NOT MATCHED
DESCRIPTION:
Immobilizer Control Module checks if Transponder code transmitted from ignition key and that registered in Immo-
bilizer Control Module match when ignition switch is ON. If they do not, this DTC is set.
INSPECTION:
Register ignition key with built-in transponder by using Suzuki scan tool (TECH1 cartridge for immobilizer control
system and TECH 1A kit) and performing following steps.
1) Register Transponder code in Immobilizer Control Module by performing procedure described in ªHow to regis-
ter ignition keyº section.
2) Turn ignition switch OFF, then turn it ON and check that DTC11 is not set.
DTC31 TRANSPONDER CODE NOT REGISTERED
DESCRIPTION:
Immobilizer Control Module checks if Transponder code transmitted from ignition key and that registered in Immo-
bilizer Control Module match when ignition switch is ON. If there is no Transponder code registered in Immobilizer
Control Module, this DTC is set.
INSPECTION:
Register ignition key with built-in transponder by using Suzuki scan tool (TECH1 cartridge for immobilizer control
system and TECH 1A kit) and performing following steps.
1) Register Transponder code in Immobilizer Control Module by performing procedure described in ªHow to regis-
ter ignition keyº section.
2) Turn ignition switch OFF, then turn it ON and check that DTC31 is not set.
DTC12 FAULT IN IMMOBILIZER CONTROL MODULE
DESCRIPTION:
This DTC is set when an internal fault is detected in Immobilizer Control Module.
INSPECTION:
STEPACTIONYESNO
11) Ignition switch OFF.
2) Disconnect connectors from Immobi-
lizer Control Module.
3) Check for proper connection to Im-
mobilizer Control Module at all termi-
nals.
Are they in good condition?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.Repair or replace.

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.