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AUTOMATIC TRANSMISSION (4 A/T) 7B1-7
Diagnosis
This vehicle is equipped with an electronic transmission control system, which control the automatic shift up and
shift down timing, TCC operation, etc. suitably to vehicle driving conditions.
PCM (ECM) has an On-Board Diagnosis system which detects a malfunction in this system and abnormality of
those parts that influence the engine exhaust emission.
When diagnosing a trouble in the transmission including this system, be sure to have full understanding of the
outline of “ON-BOARD DIAGNOSTIC SYSTEM” and each item in “PRECAUTION IN DIAGNOSING TROUBLE”
and execute diagnosis according to “AUTOMATIC TRANSMISSION DIAGNOSTIC FLOW TABLE” to obtain
correct result smoothly.
On-Board Diagnostic System (Vehicle without
monitor connector)
For automatic transmission control system, PCM (ECM) has fol-
lowing functions. Refer to Section 6-1 for details.
•When the ignition switch is turned ON with the engine at a
stop, malfunction indicator lamp (MIL) (1) turns ON to check
the bulb of the MIL.
•When PCM detects a malfunction in A/T control system
(and/or a malfunction which gives an adverse effect to vehi-
cle emission) while the engine is running, it makes the mal-
function indicator lamp in the meter cluster of the instrument
panel turn ON and stores the malfunction area.
(If it detects that continuously 3 driving cycles are normal
after detecting a malfunction, however, it makes MIL (1) turn
OFF although DTC stored in its memory will remain.)
•It is possible to communicate through DLC (3) by using not
only SUZUKI scan tool (2). (Diagnostic information can be
accessed by using a scan tool (2).)
2 DRIVING CYCLE DETECTION LOGIC
Refer to Section 6-1 for details.
PENDING DTC
Refer to Section 6-1 for details.
FREEZE FRAME DATA
Refer to Section 6-1 for details.
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7B1-8 AUTOMATIC TRANSMISSION (4 A/T)
On-Board Diagnostic System (Vehicle with
monitor connector)
For automatic transmission control system, PCM (ECM) has fol-
lowing functions. Refer to Section 6/6-1 for details.
•When the ignition switch is turned ON with the engine at a
stop, malfunction indicator lamp (MIL) turns ON to check the
bulb of the MIL.
•When PCM detects a trouble in electronic shift control sys-
tem, it stores its trouble code in ECM back-up memory. (The
memory is kept as it is even if the trouble was only tempo-
rary and disappeared immediately. And it is not erased
unless the power to PCM is shut off for 30 seconds or
longer.)
•It is possible to communicate through DLC by using not only
SUZUKI scan tool (2) but also generic scan tool. (Diagnostic
information can be accessed by using a scan tool.)
•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 (3) is con-
nected to ground terminal (4) with a service wire (5) and igni-
tion switch is turned ON.)
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AUTOMATIC TRANSMISSION (4 A/T) 7B1-13
Malfunction Indicator Lamp (MIL) Check
Refer to the same item in Section 6-1 for checking procedure.
“O/D OFF” Lamp Check
1) Check that O/D off switch button is at OFF position (pushed).
2) Turn ignition switch ON.
3) Check that “O/D OFF” lamp lights for about 2 – 4 sec. and
then goes OFF.
If anything faulty is found, advance “DIAGNOSTIC FLOW
TABLE B-1 or B-2 “O/D OFF” LAMP CIRCUIT CHECK”.
“POWER” Lamp Check
1) Check that Power/Normal change switch button is at Normal
position.
2) Turn ignition switch ON.
3) Check that “POWER” lamp lights for about 2 – 4 sec. and
then goes OFF.
If anything faulty is found, advance “DIAGNOSTIC FLOW
TABLE B-3 or B-4 “POWER” LAMP CIRCUIT CHECK”.
Diagnostic Trouble Code (DTC) Check
Refer to the same item in Section 6-1 for checking procedure.
Diagnostic Trouble Code Clearance
Refer to the same item in Section 6-1 for clearance procedure.
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7B1-18 AUTOMATIC TRANSMISSION (4 A/T)
Table A-1 : No TCC Lock-Up Occurs
SYSTEM DESCRIPTION
PCM turns TCC solenoid OFF under any of the following conditions.
•Brake pedal switch : ON
•4WD LOW switch : ON
•Cruise control module : TCC OFF command signal is output (if equipped).
•ECT : ECT < 30 °C (86 °F)
TROUBLESHOOTING
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent and very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 person, a driver and tester, on a level road.
Step Action Yes No
1Was “AUTOMATIC TRANSMISSION DIAG-
NOSTIC FLOW TABLE” performed?Go to Step 2. Go to “AUTOMATIC
TRANSMISSION DIAG-
NOSTIC FLOW TABLE” in
this section.
2 ECT check :
1) Warm up engine to normal operating tem-
perature.
2) Check ECT using scan tool.
Is ECT more than 30 °C (86 °F)?Go to Step 3. Faulty ECT sensor, its cir-
cuit or engine cooling sys-
tem.
If OK, substitute a known-
good PCM and recheck.
3 Perform running test under the following condi-
tions and check voltage between C51-1-8 termi-
nal of PCM coupler and ground.
•Normal mode in “D” range.
•Transfer “2H” position.
•Cruise control is not operated (if equipped).
•Brake pedal released.
•Drive vehicle with TCC ON condition refer-
ring to “TCC LOCK-UP DIAGRAM” in this
section.
Is it battery voltage?Faulty TCC solenoid
valve, its circuit or trans-
mission.Go to Step 4.
4 Brake switch signal inspection :
With ignition switch ON, check voltage between
E61-34 terminal of PCM coupler terminal and
ground.
Brake switch specification
Brake pedal released : 0 V
Brake pedal depressed : Battery voltage
Is the result as specified?Go to Step 5. Faulty brake pedal switch
or its circuit.
If OK, substitute a known-
good PCM and recheck.
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AUTOMATIC TRANSMISSION (4 A/T) 7B1-19
5“4WD LOW” switch signal inspection :
With ignition switch ON, check voltage between
C51-1-26 terminal of PCM coupler and ground.
“4WD LOW” switch specification
Transfer gear position “4L” or “N” : 0 V
Transfer gear position “4H” or “2H” :
Battery voltage
Is the result as specified?Go to Step 6. Faulty “4WD LOW” switch
or its circuit.
If OK, substitute a known-
good PCM and recheck.
6 Is vehicle equipped with cruise control system? Go to Step 7. Substitute a know-good
PCM and recheck.
7 Cruise control signal inspection :
With ignition switch ON, check voltage between
E61-35 terminal of PCM coupler and ground.
Is it battery voltage?Substitute a known-good
PCM and recheck.Faulty cruise control mod-
ule or its circuit.
If OK, substitute a known-
good PCM and recheck. Step Action Yes No
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7B1-20 AUTOMATIC TRANSMISSION (4 A/T)
Table A-2 : No Gear Shift to O/D
SYSTEM DESCRIPTION
PCM does not shift to O/D gear under any of the following conditions.
•O/D off switch : ON
•4WD LOW switch : ON
•Cruise control module : O/D OFF command signal is output (if equipped).
•ECT : ECT < 30 °C (86 °F)
TROUBLESHOOTING
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent and very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 person, a driver and tester, on a level road.
Step Action Yes No
1Was “AUTOMATIC TRANSMISSION DIAG-
NOSTIC FLOW TABLE” performed?Go to Step 2. Go to “AUTOMATIC
TRANSMISSION DIAG-
NOSTIC FLOW TABLE” in
this section.
2 ECT check :
1) Warm up engine to normal operating tem-
perature.
2) Check ECT using scan tool.
Is ECT more than 30 °C (86 °F)?Go to Step 3. Faulty ECT sensor, its cir-
cuit or engine cooling sys-
tem.
If OK, substitute a known-
good PCM and recheck.
3 Perform running test under the following condi-
tions and check voltage between C51-1-2 termi-
nal of PCM coupler and ground, C51-1-1
terminal of PCM coupler and ground.
•O/D off switch OFF (“O/D OFF” lamp OFF).
•Normal mode in “D” range.
•Transfer “2H” position.
•Cruise control is not operated (if equipped).
•Drive vehicle with 4th gear condition refer-
ring to “Gear shift diagram” in this section.
Is each voltage about 0 V?Faulty shift solenoid valve,
its circuit or transmission“GRN” wire or “GRN/
RED” wire shorted to
power circuit.
If OK, go to Step 4.
4 O/D off switch signal inspection :
With ignition switch ON, check voltage between
E61-33 terminal of PCM coupler and ground.
“O/D” cut switch specification
“O/D” cut switch OFF : Battery voltage
“O/D” cut switch ON : 0 V
Is the result as specified?Go to Step 5. Faulty O/D off switch or its
circuit.
If OK, substitute a known-
good PCM and recheck.
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AUTOMATIC TRANSMISSION (4 A/T) 7B1-21
5“4WD LOW” switch signal inspection :
With ignition switch ON, check voltage between
C51-1-26 terminal of PCM coupler and ground.
“4WD LOW” switch specification
Transfer gear position “4L” or “N” : 0 V
Transfer gear position “4H” or “2H” :
Battery voltage
Is the result as specified?Go to Step 6. Faulty “4WD LOW” switch
or its circuit.
If OK, substitute a known-
good PCM and recheck.
6 Is vehicle equipped with cruise control system? Go to Step 7. Substitute a known-good
PCM and recheck.
7 Cruise control signal inspection :
With ignition switch ON, check voltage between
E61-35 terminal of PCM coupler and ground.
Is it battery voltage?Substitute a known-good
PCM and recheck.Faulty cruise control mod-
ule or its circuit.
If OK, substitute a known-
good PCM and recheck. Step Action Yes No
Page 431 of 656
7B1-22 AUTOMATIC TRANSMISSION (4 A/T)
Table B-1 : “O/D OFF” Light Circuit Check (“O/D OFF” Light Doesn’t Light at
Ignition Switch ON But Engine Starts Up)
WIRING DIAGRAM
TROUBLESHOOTING
1. PCM 4. P/N change switch
2. Fuse 5. J/C
3. O/D off switch 6. J/C
Step Action Yes No
1“O/D OFF” light circuit check:
1) With ignition switch OFF, disconnect cou-
plers from PCM.
2) Using service wire, connect E61-20 termi-
nal of disconnected PCM coupler and
ground.
Does “O/D OFF” light turn ON at ignition switch
ON?Poor E61-20 terminal con-
nection.
If OK, substitute a know-
good PCM and recheck.Bulb burned out or faulty
“WHT/BLK”, “BLK/WHT”
wire.