Pcm SUZUKI GRAND VITARA 1998 2.G Service User Guide

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
7B1-22 AUTOMATIC TRANSMISSION (4 A / T)
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.
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 unnec-
essary.
3 and 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.
5. TROUBLE SYMPTOM CONFIRMATION
Check trouble symptoms based on information obtained in Step 1 ªCUSTOMER COMPLAINT ANALYSISº and
Step 2 ªDTC/FREEZE FRAME DATA CHECKº.
Also, recheck DTC according to ªDTC Confirmation Procedureº described in each ªDTC FLOW TABLEº.
6 and 7. RECHECKING AND RECORD OF DTC/FREEZE FRAME DATA
Refer to ªDTC Checkº section for checking procedure.
8. A/T BASIC CHECK AND TROUBLE DIAGNOSIS TABLE
Perform A / T basic check according to the ªA / T Basic Check Flow Tableº 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 DIAG-
NOSIS TABLE and based on symptoms appearing on the vehicle (symptoms obtained through steps of custom-
er complaint analysis, trouble symptom confirmation and/or A / T basic check) and repair or replace faulty parts,
if any.
9. DIAGNOSTIC TROUBLE CODE FLOW TABLE
Based on the DTC indicated in Step 6 and 7 and referring to ªDIAGNOSTIC TROUBLE CODE FLOW TABLEº
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.
10. CHECK FOR INTERMITTENT PROBLEM
Check parts where an intermittent trouble is easy to occur (e.g., wire harness, connector, etc.), referring to
ªINTERMITTENT AND POOR CONNECTIONº in Section 0A and related circuit of DTC recorded in Step 2.
11. FINAL CONFIRMATION TEST
Confirm that the problem symptom has gone and the A / T is free from any abnormal conditions.
If what has been repaired is related to the malfunction DTC, clear the DTC once, set conditions under which
DTC was detected and A / T and/or vehicle was repaired and confirm that no DTC is indicated.

YH4
GRAND
VITARA
7B1-24 AUTOMATIC TRANSMISSION (4 A / T)
MALFUNCTION INDICATOR LAMP (MIL) CHECK
Refer to the same item in Section 6 / 6-1 for checking procedure.
ªO / D OFFº LAMP CHECK
1) Check that O / D cut switch button is at OFF position (pushed).
2) Turn ignition switch ON.
3) Check that ªO / D OFFº lamp lights for about 2 ± 4 sec. and then goes OFF.
If anything faulty is found, advance ªDiagnostic flow table B-1 or B-2º O / D OFF ªLAMP CIRCUIT CHECKº.
ªPOWERº LAMP CHECK
1) Check that Power / Normal change switch button is at Normal position.
2) Turn ignition switch ON.
3) Check that ªPowerº Lamp light for 2 ± 4 sec. and then goes OFF.
If anything faulty is found, advance ªDiagnostic flow table B-3 or B-4 ªPOWERº LAMP CIRCUIT CHECK 2.
DIAGNOSTIC TROUBLE CODE (DTC) CHECK
Refer to the same item in Section 6 / 6-1 for checking procedure.
DIAGNOSTIC TROUBLE CODE (DTC) CLEARANCE
Refer to the same item in Section 6 / 6-1 for clearance procedure.
DIAGNOSTIC TROUBLE CODE (DTC) TABLE (A / T RELATED CODE)
DTC NO.MIL
Using
scan toolNot using
scan toolDETECTED ITEMDETECTING CONDITION
Vehicle
without
monitor
connectorVehicle
with
monitor
connector
±12±No trouble.±±
P070572Transmission range
sensor circuit
Multiple signals inputted simulta-
neously or no signal inputted while
2 driving
cycles
Not
applicablesensor circuit
malfunction
neously or no signal in utted while
running at 60 km / h or more.
cyclesa licable
P071576Input / Turbine speed
sensor circuit
malfunctionInput shaft revolution speed is lower
than specified value while
vehicle is running with ªDº range and
specified engine speed or higher.2 driving
cyclesNot
applicable
P072075Output speed sensor
circuit malfunctionOutput speed sensor signal not
inputted while VSS signal being
inputted.2 driving
cyclesNot
applicable
*1
P0741
Not
applicableTCC (lock-up) solenoid
performance or stack
offActual TCC operation does not
agree with ON / OFF control from
PCM to TCC.2 driving
cyclesNot
applicable
P074365
66TCC (lock-up)
solenoid electricalMonitor signal OFF is detected
When TCC control solenoid is ON or
monitor signal ON is detected when
it is OFF.1 driving
cycleNot
applicable
*1
P0751
Not
applicableShift solenoid A (#1)
performance or stuck
offGear change control from PCM to
A / T does not agree with actual gear
position of A / T.2 driving
cyclesNot
applicable
P075361
62Shift solenoid A (#1)
electricalMonitor signal OFF is detected
when shift solenoid A (#1) is ON or
monitor signal ON is detected when
it is OFF.1 driving
cycleNot
applicable

YH4
GRAND
VITARA
AUTOMATIC TRANSMISSION (4 A / T) 7B1-25
DIAGNOSTIC TROUBLE CODE (DTC) TABLE (A / T RELATED CODE) (cont'd)
DTC NO.MIL
Using
scan toolNot using
scan toolDETECTED ITEMDETECTING CONDITION
Vehicle
without
monitor
connectorVehicle
with
monitor
connector
*1
P0756
Not
applicableShift solenoid B (#2)
performance or stuck
offGear change control from PCM to
A / T does not agree with actual gear
position of A / T.2 driving
cyclesNot
applicable
P075863
64Shift solenoid B (#2)
electricalMonitor signal OFF is detected
when shift solenoid B (#2) is ON or
monitor signal ON is detected when
it is OFF.1 driving
cycleNot
applicable
*1
P1875
Not
applicable4WD low switch circuit
malfunctionDifference between vehicle speed
detected by VSS and vehicle speed
detected by output speed sensor
and compensated by 4WD low
switch is larger than specification.2 driving
cyclesNot
applicable
NOTE:
*1: Applicable to vehicle without monitor connector only.
FAIL-SAFE TABLE
When any of the following DTC is detected, ECM (PCM) enters fail-safe mode as long as malfunction continues
to exist but that mode is canceled when ECM detects normal condition after that.
DTC NO.
Using
scan toolNot using
scan toolTROUBLE AREAFAIL SAFE OPERATION
P0177
P011814
15ECT SENSOR
Each control except 4-A / T is permitted on the basis of
30.1C engine coolant temp.

4-A / T control is performed assuming 31C (engine warmed
up) or higher after 15 min. from engine start.
P0122
P012321
22TP SENSOR
Each control except 4-A / T is performed on the basis of 124
throttle valve opening.

4-A / T control is performed on the basis of 0 throttle valve
opening.
P070572TR SWITCHA / T control is performed in priority order of L, 2, N, D, R
and P.
P072075OUTPUT SPEED
SENSOR CIRCUIT
MALFUNCTIONA / T control is performed by using signal from VSS.
P075361
62SHIFT SOLENOID
A (#1)
A / T control using 3rd gear is performed when D range, 1st
or 2nd gear is used.

TCC solenoid OFF.
P075863
64SHIFT SOLENOID
B (#2)
A / T control using 4th gear is performed when D range 2nd
or 3rd gear is used.

When both shift solenoid A (#1) and B (#2) failed
simultaneously, A / T control using 4th gear is always
performed in D range.

TCC solenoid OFF.
P074365
66TCC (Lock-up)
SOLENOIDTCC (lock-up) solenoid OFF.

YH4
GRAND
VITARA
AUTOMATIC TRANSMISSION (4 A / T) 7B1-27
A / T BASIC CHECK
This inspection is important for troubleshooting when PCM (ECM) has detected no DTC and no abnormality has
been noted in visual inspection.
Follow flow table carefully.
STEP
ACTIONYESNO
1Was ªA / T DIAG. FLOW TABLEº performed?Go to Step 2.Go to ªA / T DIAG.
FLOW TABLEº.
2Perform MANUAL ROAD TEST in this section.
Is it OK?Go to Step 3.Go to Step 4.
3Proceed to TROUBLE DIAGNOSIS TABLE 1 in this
section.
Is trouble identified?Repair or replace
defective parts.Go to Step 5.
4Perform stall test, time rag test, line pressure test,
engine brake test and ªPº range test referring to STALL
TEST, LINE PRESSURE TEST, ENGINE BRAKE
TEST and ªPº RANGE TEST in this section.
Are the test results satisfactory?Go to Step 5.Proceed to
TROUBLE DIAGNO-
SIS TABLE 3 in this
section.
5Proceed to TROUBLE DIAGNOSIS TABLE 2 in this
section.
Is trouble identified?Repair or replace
defective parts.Proceed to
TROUBLE DIAGNO-
SIS TABLE 3 in this
section.

YH4
GRAND
VITARA
7B1-30 AUTOMATIC TRANSMISSION (4 A / T)
Running condition Gear shift Abnormal
noise
ConditionPossible CauseCorrection
Poor 1st speed run-
ning or excessive
slippage in ªDº or ª2º
Fluid pressure leakage from forward clutch
due to wear or breakage of O/D case seal
ringReplace.

Overdrive clutch slippingReplace.
Unable to run or ex-
cessive slippage in
ªLº range
Fluid pressure leakage of forward clutch
due to wear or breakage of O/D case seal
ringReplace.

Reverse brake disc slippingReplace.

Broken brake piston O-ringReplace.
Unable to run or ex-
cessive slippage in
ªRº range
Fluid pressure leakage to direct clutch due
to wear or breakage of center support seal
ringReplace.

Worn direct clutchReplace.
Poor 1±2 shift, ex-
cessive slippage
Fluid pressure leakage to overdrive clutch
due to wear or breakage of O/D case seal
ringReplace.

Faulty second brakeReplace.

Broken O-ring of second brake pistonReplace.

Faulty second coast brake (in ª2º range)Replace.
Poor 2±3 shift, ex-
cessive slippage
Fluid pressure leakage to overdrive clutch
due to wear or breakage of O/D case seal
ringReplace.

Worn direct clutch bushingReplace.

Direct clutch slippingReplace.

Foreign material caught in direct clutch pis-
ton check ballReplace.
Poor start or surging
in ªDº range
Fluid pressure leakage of forward clutch
due to wear or breakage of O/D case seal
ringReplace.

Malfunction of forward clutchReplace.
Poor 3±4 shift, ex-
ili

Faulty overdrive brakeReplace.
cessive slippage
Faulty overdrive clutchReplace.
Poor start or judder-
ing in ªRº range
Fluid pressure leakage of direct clutch due
to wear or breakage of oil center support
seal ringReplace.

Worn direct clutchReplace.
Excessive shock on
1± 2 shift
Faulty one-way clutchReplace.
Non operate lock-up
system
Faulty torque converterReplace.
Abnormal noise in
ªPº or ªNº range
Worn oil pumpReplace.
SCAN TOOL DATA-Refer to SECTION 6 / 6-1.
INSPECTION OF PCM AND ITS CIRCUIT-Refer to SECTION 6 / 6-1.
WIRE HARNESS AND CONNECTORS-Refer to SECTION 6 / 6-1.

YH4
GRAND
VITARA
AUTOMATIC TRANSMISSION (4 A / T) 7B1-31
Brake pedal Released Depressed
Voltage 0 VBattery
voltage
DIAGNOSTIC FLOW 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 < 30C (86F)
TROUBLESHOOTING
WARNING:

When performing a road test, select a place where there is no traffic or possibility of a traffic accident
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.
STEPACTIONYESNO
1Was ªAUTOMATIC TRANSMISSION
DIAGNOSTIC FLOW TABLEº performed?Go to Step 2.Go to ªAUTOMATIC
TRANSMISSION
DIAGNOSTIC FLOW
TABLEº.
2ECT check:
(1) Warm up engine to normal operating
temperature.
(2) Check ECT using scan tool.
Is ECT more than 30C (86F)?Go to Step 3.Faulty ECT sensor, its
circuit or engine cooling
system.
If OK, substitute a known-
good PCM and recheck.
3Perform running test under the following
conditions and check voltage between
C51-1-8 (G16 / J20 engines) or C51-1-2 (H25
engine) terminal of PCM coupler and ground.

Normal mode in ªDº range.

Transfer ª2Hº position.

Cruise control is not operated (if equipped).

Brake pedal released.

Drive vehicle with TCC ON condition
referring to ªTCC lock-up diagramº in
this section.
Is it battery voltage?Faulty TCC solenoid
valve, its circuit or
transmission.Go to Step 4.
4Is vehicle equipped with H25 engine?Go to Step 5.Go to Step 6.
5Brake switch signal inspection:
(1) With ignition switch ON, check voltage
between E61-31 terminal of PCM coupler
terminal and ground.
Is the result as specified?Go to Step 6.Faulty brake pedal switch
or its circuit.
If OK, substitute a known-
good PCM and recheck.

YH4
GRAND
VITARA
7B1-32 AUTOMATIC TRANSMISSION (4 A / T)
Transfer gear
positionª4Lº or ªNº ª4Hº or ª2Hº
Voltage 0 VBattery
voltage
STEPACTIONYESNO
6ª4WD LOWº switch signal inspection:
(1) With ignition switch ON, check voltage
between C51-1-26 (G16 / J20 engines) or
C51-1-5 (H25 engine) terminal of PCM
coupler and ground.
Is the result as specified?Go to Step 7.Faulty ª4WD LOWº
switch or its circuit.
If OK, substitute a known-
good PCM and recheck.
7Is vehicle equipped with cruise control
system?Go to Step 8.Substitute a known-good
PCM and recheck.
8Cruise control signal inspection:
(1) With ignition switch ON, check voltage
between E61-35 (G16 / J20 engines) or
E61-3 (H25 engine) terminal of PCM
coupler and ground.
Is it battery voltage?Substitute a known-good
PCM and recheck.Faulty cruise control
module or its circuit.
If OK, substitute a known-
good PCM and recheck.

YH4
GRAND
VITARA
AUTOMATIC TRANSMISSION (4 A / T) 7B1-33
O / D cut
switchOFF ON
VoltageBattery
voltage0 V
DIAGNOSTIC FLOW 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 cut switch: ON

4WD LOW switch: ON

Cruise control module: O / D OFF command signal is output (if equipped).

ECT: ECT < 30C (86F)
TROUBLESHOOTING
WARNING:

When performing a road test, select a place where there is no traffic or possibility of a traffic accident
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.
STEPACTIONYESNO
1Was ªAUTOMATIC TRANSMISSION
DIAGNOSTIC FLOW TABLEº performed?Go to Step 2.Go to ªAUTOMATIC
TRANSMISSION
DIAGNOSTIC FLOW
TABLEº.
2ECT check:
(1) Warm up engine to normal operating
temperature.
(2) Check ECT using scan tool.
Is ECT more than 30C (86F)?Go to Step 3.Faulty ECT sensor,
its circuit or engine
cooling system.
If OK, substitute a known-
good PCM and recheck.
3Perform running test under the following
conditions and check voltage between
C51-1-2 (G16 / J20 engines) or C51-1-6 (H25
engine) terminal of PCM coupler and ground,
C51-1-1 terminal of PCM coupler and ground.

O / D cut switch OFF (ªO / D OFFº lamp OFF).

Normal mode in ªDº range.

Transfer ª2Hº position.

Cruise control is not operated (if equipped).

Drive vehicle with 4th gear condition
referring to ªGear shift diagramº in this
section.
Is each voltage about 0 V?Faulty shift solenoid
valve, its circuit or
transmission.ªGº wire or ªG / Rº wire
shorted to power circuit.
If OK, go to Step 4.
4O / D cut switch signal inspection:
(1) With ignition switch ON, check voltage
between E61-33 (G16 / J20 engines) or
E61-14 (H25 engine) terminal of PCM
coupler and ground.
Is the result as specified?Go to Step 5.Faulty O / D cut switch or
its circuit.
If OK, substitute a known-
good PCM and recheck.

YH4
GRAND
VITARA
7B1-34 AUTOMATIC TRANSMISSION (4 A / T)
Transfer gear
positionª4Lº or ªNº ª4Hº or ª2Hº
Voltage 0 VBattery
voltage
STEPACTIONYESNO
54WD LOW switch signal inspection:
(1) With ignition switch ON, check voltage
between C51-1-26 (G16 / J20 engines) or
C51-1-5 (H25 engine) terminal of PCM
coupler and ground.
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.
6Is vehicle equipped with cruise control
system?Go to Step 7.Substitute a known-good
PCM and recheck.
7Cruise control signal inspection:
(1) With ignition switch ON, check voltage
between E61-35 (G16 / J20 engines) or
E61-3 (H25 engine) terminal of PCM
coupler and ground.
Is it battery voltage?Substitute a known-good
PCM and recheck.Faulty cruise control
module or its circuit.
If OK, substitute a known-
good PCM and recheck.