Page 433 of 801

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.
Page 435 of 801

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.
Page 451 of 801

YH4
GRAND
VITARA
AUTOMATIC TRANSMISSION (4 A / T) 7B1-49
DTC P0751 SHIFT SOLENOID VALVE-A (#1) PERFORMANCE OR STUCK OFF
DTC P0756 SHIFT SOLENOID VALVE-B (#2) PERFORMANCE OR STUCK OFF
DTC DETECTING CONDITION AND TROUBLE AREA
DTC DETECTING CONDITIONTROUBLE AREA
While running in D range, gear change control from
PCM to A / T does not agree with actual A / T gear posi-
tion even though solenoid valve is electrically in good
condition.
(A / T gear position is calculated based on engine
speed signal and vehicle speed sensor signal.)
(2 driving cycles detection logic)DTC P0751:
Shift solenoid valve-A stuck or leakage.
2-3 shift valve stuck.
Valve body fluid passage clogged.
Mechanical malfunction in transmission.
(Direct clutch malfunction)
DTC P0756:
Shift solenoid valve-B stuck or leakage.
1-2 shift valve stuck.
3-4 shift valve stuck.
Valve body fluid passage clogged.
Mechanical malfunction in transmission.
(2nd brake malfunction)
DTC CONFIRMATION PROCEDURE
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic accident
and be very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 persons, a driver and a tester, on a level road.
1) Connect scan tool to DLC with ignition switch OFF.
2) Clear DTC, pending DTC and freeze frame data in PCM memory by using scan tool and check fuel level meter
indication is 1 / 4 or more.
3) Start engine, warm it up to normal operating temperature and shift transfer lever to ª2Hº or ª4Hº range.
4) Increase vehicle speed with D range, and check that gear position changes from 1st to 2nd, 3rd and 4th in that
order as vehicle speed increases, referring to ªGear Shift Diagramº in this section.
5) Stop vehicle and check pending DTC and DTC by using scan tool.
TROUBLESHOOTING
STEPACTIONYESNO
1Was ªA / T DIAG. FLOW TABLEº performed?Go to Step 2.Go to ªA / T DIAG.
FLOW TABLEº.
2Shift solenoid valve-A or -B operation check:
1) Check shift solenoid valve-A or -B for operation
referring to ªSolenoid Valves Operation Checkº
section.
Is it in good condition?Go to Step 3.Faulty shift solenoid
valve-A or -B.
3Valve body check:
1) Check valve body and its passage referring to
ªUnit Repairº section.
Are they in good condition?Overhaul and repair
automatic transmis-
sion.Faulty valve body.
Page 552 of 801
YH4
GRAND
VITARA
8C-10 INSTRUMENTATION / DRIVER INFORMATION
G16
J20
H25
1. ECT sensor
1
ENGINE COOLANT TEMP. (ECT) METER AND
SENSOR
ENGINE COOLANT TEMPERATURE (ECT) METER
INSPECTION
1) Disconnect Y/W lead wire going to ECT sensor.
2) Turn ignition switch ON, and check that ECT meter indicates
COOL.
3) Turn ignition switch OFF.
4) Ground Y/W lead wire through a 3.4 W test bulb (1) as illustrated.
5) Turn ignition switch ON, and check that bulb light up and pointer
(2) moves to hot side.
6) If ECT meter shows no operation, repair or replace defective
parts.
ENGINE COOLANT TEMPERATURE (ECT) SENSOR
REMOVAL AND INSTALLATION
Refer to ECT SENSOR in ON-VEHICLE SERVICE in Section 6E1
(for G16 and J20) or Section 6E2 (for H25) of this manual for details.
Page 553 of 801
YH4
GRAND
VITARA
G16
J20
H25
1. Oil pressure switch
INSTRUMENTATION / DRIVER INFORMATION 8C-11
INSPECTION
1) Warm up ECT sensor (1) observing resistance between sensor
terminal (2) and sensor unit (1). Resistance should be de-
creased with increase of its temperature.
2) Check resistance between sensor terminal (2) and sensor unit
(1) shown below. If check result is not as specified, replace sen-
sor.
Temperature
Resistance
50C (122F)136 ± 216
OIL PRESSURE LIGHT
OIL PRESSURE SWITCH
REMOVAL AND INSTALLATION
Refer to OIL PRESSURE CHECK in Section 6A1 (for G16), Section
6A2 (for H25), and Section 6A4 (for J20) of this manual for details.
INSPECTION
1) Disconnect oil pressure switch (1) lead wire.
2) Check for continuity between oil pressure switch terminal (2)
and cylinder block (3) as shown.
During Engine Running
No continuity
At Engine StopContinuity
If check result is not as specified, replace oil pressure switch (1).