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.)
AUTOMATIC TRANSMISSION (4 A/T) 7B1-11
STEP 1. CUSTOMER COMPLAINT ANALYSIS
Record details of the problem (failure, complaint) and how it occurred as described by the customer.
For this purpose, use of such a inspection form will facilitate collecting information to the point required for
proper analysis and diagnosis.
STEP 2. DIAGNOSTIC TROUBLE CODE (DTC)/FREEZE FRAME DATA CHECK, RECORD AND
CLEARANCE
First, referring to DTC check section, check DTC (including pending DTC). If DTC exists, print or write down
DTC and freeze frame data and then clear them by referring to DTC clearance section. DTC indicates malfunc-
tion in the system but it is not possible to know from it whether the malfunction is occurring now or it occurred in
the past and normal condition has been restored. In order to know that, check symptom in question according to
Step 5 and then recheck DTC according to Step 6.
Diagnosing a trouble based on the DTC in this step only or failure to clear the DTC in this step may result in an
faulty diagnosis, trouble diagnosis of a normal circuit or difficulty in troubleshooting which is otherwise unneces-
sary.
STEP 3 and STEP 4. VISUAL INSPECTION
As a preliminary step, be sure to perform visual check of the items that support proper function of the A/T and
engine referring to Visual Inspection section.
STEP 5. TROUBLE SYMPTOM CONFIRMATION
Check trouble symptoms based on information obtained in Step 1 “CUSTOMER COMPLAINT ANALYSIS” and
Step 2 “DTC/FREEZE FRAME DATA CHECK”.
Also, recheck DTC according to “DTC CONFIRMATION PROCEDURE” described in each “DTC FLOW
TABLE”.
STEP 6 and STEP 7. RECHECKING AND RECORD OF DTC/FREEZE FRAME DATA
Refer to “DTC CHECK” in this section for checking procedure.
STEP 8. A/T BASIC CHECK AND TROUBLE DIAGNOSIS TABLE
Perform A/T basic check according to the “A/T Basic Check Flow Table” first. When the end of the flow table has
been reached, check the parts of the system suspected as a possible cause referring to “TROUBLE DIAGNO-
SIS TABLE” and based on symptoms appearing on the vehicle (symptoms obtained through steps of customer
complaint analysis, trouble symptom confirmation and/or A/T basic check) and repair or replace faulty parts, if
any.
STEP 9. DIAGNOSTIC TROUBLE CODE FLOW TABLE
Based on the DTC indicated in Step 6 and 7 and referring to “DIAGNOSTIC TROUBLE CODE FLOW TABLE” in
this section, locate the cause of the trouble, namely in a sensor, switch, wire harness, connector, actuator, PCM
or other part and repair or replace faulty parts.11 Final Confirmation Test
1) Clear DTC if any.
2) Perform final confirmation test referring to
the next page.
Is there any problem symptom, DTC or abnor-
mal condition?Go to Step 6. End. Step Action Yes No
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.
AUTOMATIC TRANSMISSION (4 A/T) 7B1-15
Trouble Diagnosis Table 1
Trouble Diagnosis Table 2
TRANSMISSION FLUID
RUNNING CONDITION
4 Perform stall test, time rag test, line pressure test,
engine brake test and “P” range test referring to
“STALL TEST”, “LINE PRESSURE TEST”, “ENGINE
BRAKE TEST” and ““P” RANGE TEST” in this section.
Are the test results satisfactory?Go to Step 5. Proceed to “TROUBLE
DIAGNOSIS TABLE 3” in
this section.
5 Proceed to “TROUBLE DIAGNOSIS TABLE 2” in this
section.
Is trouble identified?Repair or replace
defective parts.Proceed to “TROUBLE
DIAGNOSIS TABLE 3” in
this section. Step Action Yes No
Condition Possible Cause Correction
TCC does not operateBrake pedal (stop lamp) switch or its circuit
faulty (H25 engine only)Refer to “DIAGNOSTIC FLOW
TABLE A-1” in this section.
4WD low switch or its circuit faulty
Engine coolant temp. sensor or its circuit faulty
Cruise control signal circuit faulty (if equipped)
Gear does not change
to 4thO/D off switch or its circuit faulty Refer to “DIAGNOSTIC FLOW
TABLE A-2” in this section.
4WD low switch or its circuit faulty
Engine coolant temp. sensor or its circuit faulty
Cruise control signal circuit faulty (if equipped)
Condition Possible Cause Correction
Low fluid pressureClogged oil pump strainer Wash strainer.
Malfunction of pressure regulator valve Overhaul valve body.
High fluid pressurePressure regulator valve Overhaul valve body.
Condition Possible Cause Correction
Unable to run in all
rangeRegulator valve stick Replace.
Clogged oil strainer Wash strainer.
Seized or broken planetary gear Repair or replace.
Faulty manual valve Replace.
Poor 1st speed run-
ning or excessive slip-
page in “D” or “2”Faulty 1–2 shift valve Replace.
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.
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
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.
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