AUTOMATIC TRANSMISSION (4 A/T) 7B-9
A/T hardware itself
(DTC P0730)Difference in detected
revolution between
input shaft speed
sensor and output
shaft speed sensor is
too wide.“P” range →
P, “R” range →
R, “N” range →
N,
“D”/“2”/“L” range “To be controlled as follows :
1) When detecting trouble at first, gear is selected well-suited
gear calculated with parameters of each sensor’s rev. num-
ber and gear position just when the trouble occurred. Lock-
up function is turned OFF.
2) If A/T can transmit driving force under the above condition,
gear is fixed the selected gear until ignition switch is turned
OFF.
3) If A/T can not transmit driving force under the above condi-
tion, after once vehicle stop, gear which can transmit drive
force is searched one by one until gear is found out. After
gear is found out, position of gear is held until ignition switch
is turned OFF.
Transmission
range sensor cir-
cuit
(DTC P0705)No shift switch signal
is inputted or two or
more shift switch sig-
nals are inputted at
the same time.When vehicle running, shift range position is fixed to shift
range position right before the trouble occurred until vehicle
stop and lock-up function is turned OFF.
When vehicle is at stop after or during detecting the trouble,
gear is fixed as the followings and lock-up function is turned
OFF.
–When 2 adjoining gear position signals are inputted.
“P”, “R” range →
R, “R”, “N” range →
R,
“N”, “D” range →
D, “D”, “2” range →
D,
“2”, “L” range →
2nd
–When 2 or more signals excepting above or no signal are
inputted.
“P” range →
P, “R” range →
R,
“N” range →
N, “D”/“2”/“L” range →
3rd
Transmission tem-
perature sensor cir-
cuit
(DTC P0710)A/T fluid temp. sig-
nal input voltage is
too low.
A/T fluid temp. sig-
nal input voltage
does not go down
although standard
value of engine
rev. signal is input-
ted.When detecting circuit open, TCM control as fluid tempera-
ture is 100°C (212°F).
Lock-up function is turned OFF.
Engine speed input
circuit
(DTC P0725)Inputted engine rev.
signal is too low or
too high.Engine rev. is processed as 4000 rpm.
No compensation or judgement for gear shift control, for
which engine rev. is considered, is processed.
Lock-up function is turned OFF.
Engine coolant
temp./Barometric
pressure signal cir-
cuit
(DTC P1709)No or abnormal
engine coolant temp.
signal is inputtedNo compensation for gear shift control, for which engine cool-
ant temp. and barometric pressure are considered, is pro-
cessed.
Lock -up function is turned OFF. Area Detecting condition Fail safe function
7B-10 AUTOMATIC TRANSMISSION (4 A/T)
CHANGE MECHANISM
The same select pattern shift lever is used as the floor type and
frequently used “N” and “D” ranges are made selectable freely. Throttle position
signal circuit
(DTC P1700)No or abnormal throt-
tle opening signal is
inputtedScheduling of automatic gear shift is performed as throttle
valve opening is 0%.
Control of automatic gear shift (i.e. control of oil pressure) is
performed as throttle valve opening is 100%.
Coast down shifting is performed when brake is applied and
engine rev. is less than 1,500 rpm.
Lock-up function is turned OFF.
Transmission con-
trol system electri-
cal
(DTC P0702)Solenoid power sup-
ply relay output volt-
age is too high
although TCM orders
relay to turn off or
relay output voltage is
too low although TCM
orders relay to turn
on.When relay shorted, the gear is fixed as the followings and
lock-up function is turned OFF.
“P” range →
P, “R” range →
R, “N” range →
N,
“D” range →
3rd, “2” range →
2nd, “L” range →
1st
When relay open, power supply to all solenoids is cut and the
gear is fixed as the followings. Lock-up function is turned
OFF.
“P” range →
P, “R” range →
R, “N” range →
N,
“D”/“2”/“L” range →
3rd
Internal malfunc-
tion of TCM
(DTC P1702)Incorrect calculations
of checking TCM pro-
grammed data indi-
cated.Power supply to all solenoid is cut and the gear is fixed as fol-
lows :
“P” range P, “R” range R, “N” range N,
“D”/“2”/“L” range “3rd Area Detecting condition Fail safe function
7B-16 AUTOMATIC TRANSMISSION (4 A/T)
2. DIAGNOSTIC TROUBLE CODE (DTC) CHECK, RECORD AND CLEARANCE
To check DTC, refer to “DTC CHECK” in this section. When a DTC exists, it means existence of a malfunction in
the system represented by that code but whether it still exists (current) or it occurred in the past and has gone
(history) is unknown. To know it, clear this DTC once (Refer to “DTC CLEARANCE” in this section.), perform
test drive and/or “TROUBLE SYMPTOM CONFIRMATION” in this section and then check DTC again as
described in “DTC CHECK”. Attempt to diagnose the trouble based on the DTC recorded in this step only or fail-
ure to clear the DTC in this step may mislead the diagnosis or make diagnosing difficult. Even after checking the
DTC with the SUZUKI scan tool, diagnosis should be performed according to this flow chart to check TCM for
proper self-diagnosis function.
3 and 4. VISUAL INSPECTION
As a preliminary step, perform visual check of the following items that support proper function of the automatic
transmission.
5.TROUBLE SYMPTOM CONFIRMATION
Check if what the customer claimed in “CUSTOMER COMPLAINT ANALYSIS” is actually found in the vehicle
and if that symptom is found, whether it is identified as a failure. (This step should be shared with the customer
if possible.)
When the symptom is not actually found, possibility is :
The symptom occurs under certain conditions.
----- Retry with the vehicle under different conditions.
The trouble occurred only temporarily and normal operation has been restored.
----- Perform “DTC CHECK” and if the diagnostic trouble code is indicated, inspect according to the flow
table for that DTC.
6 and 7. RECHECKING AND RECORD OF DTC
Refer to “DTC CHECK” in this section.INSPECTION ITEM REFERRING SECTION
Engine oil ----- level, leakage Section 0B
Engine coolant ----- level, leakage Section 0B
A/T fluid ----- level, leakage, color Section 0B
Battery ----- fluid level, corrosion of terminal
A/T fluid hoses ----- disconnection, looseness, deterioration
Connectors of electric wire harness ----- disconnection, friction Section 8
Fuses ----- burning Section 8
Parts ----- installation, bolt ----- looseness
Parts ----- deformation
Other parts that can be checked visually
Also add following items at engine start.
Indicator, warning lights in combination meter ----- ON
(indicating abnormality in system) or OFFSection 8C
Other parts that can be checked visually
AUTOMATIC TRANSMISSION (4 A/T) 7B-17
8. AUTOMATIC TRANSMISSION BASIC CHECK AND TROUBLE DIAGNOSIS TABLE
Perform basic automatic transmission check according to the list below first. When the end of the list has been
reached, check the part of system suspected as a possible cause referring to “TROUBLE DIAGNOSIS TABLE”
and based on symptoms appearing on vehicle (symptoms obtained through steps of customer complaint analy-
sis, trouble symptom confirmation and/or A/T basic check) and repair or replace faulty parts, if any.
AUTOMATIC TRANSMISSION BASIC CHECK LIST
1) Power Supply Voltage Check
Check that the battery voltage is within 10 – 14 V at engine stop.
2) A/T Fluid Check
Check A/T fluid level and quality.
3) STALL TEST
Perform stall test. Refer to “STALL TEST” in this section for details.
4) LINE PRESSURE TEST
Perform line pressure test. Refer to “LINE PRESSURE TEST” in this section.
5) ROAD TEST
Perform road test to understand correctly the trouble area.
6) Electrical Harness and Coupler Check
Check the connection of the harness coupler. Check for the loose connection of the harness, loose connec-
tion of the terminals.
9. DIAGNOSTIC TROUBLE CODE FLOW TABLE
Based on the DTC indicated in STEP 6 and STEP 7 and referring to “DTC CHECK”, locate the cause of the
trouble, namely in a sensor, switch, wire harness, connector, actuator, TCM 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
“INTERMITTENT AND POOR CONNECTION” 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 automatic transmission is free from any abnormal condi-
tions. If what has been repaired is related to the malfunction DTC, clear the DTC once and perform test driving
and confirm that a normal code is indicated.
7B-18 AUTOMATIC TRANSMISSION (4 A/T)
TROUBLE DIAGNOSIS TABLE
TABLE 1 (ELECTRICAL)
NOTE:
For the inspection of throttle position sensor, refer to “TP SENSOR” in Section 6E.
Condition Possible Cause Correction
No up-shift
1st
→
→→ → 2nd
2nd
→
→→ → 3rdOutput shaft speed sensor or its circuit faulty Inspect output shaft speed sen-
sor.
Shift solenoid -D (No.4) (1st →
→→ →
2nd), -A
(No.1) (1st →
→→ →
3rd), -E (No.5) (2nd →
→→ →
3rd),
and/or its circuit faultyRepair or replace.
Throttle position sensor or its circuit faulty Inspect TP sensor.
TCM faulty Replace TCM.
3rd
→
→→ → 4th
Output shaft speed sensor or its circuit faulty Inspect output shaft speed sen-
sor.
Shift solenoid -B (No.2), -C (No.3) or its cir-
cuit faultyRepair or replace.
O/D CUT switch circuit faulty Refer to “O/D OFF SWITCH” in
this section and/or inspect its cir-
cuit.
Throttle position sensor or its circuit faulty Inspect TP sensor.
TCM faulty Replace TCM.
No down-shift
4th
→
→→ → 3rd
3rd
→
→→ → 2nd
2nd
→
→→ →1stShift solenoid -C (No.3) (4th →
→→ →
3rd), -D
(No.4) (2nd →
→→ →
1st), -A (No.1) (3rd →
→→ →
2nd), -B
(No.2) (4th →
→→ →
3rd), -E (No.5) (3rd →
→→ →
2nd) or
its circuit faultyRepair or replace.
Throttle position sensor or its circuit faulty Inspect TP sensor.
TCM fault Replace TCM.
Shift point too high or
too lowThrottle position sensor, output shaft speed
sensor or its circuit faultyInspect TP sensor and/or output
shaft speed sensor.
Vehicle does not move
Shift solenoid -A (No.1), -C (No.3), -D (No.4)
or its circuit faultyRepair or replace.
Excessive slip
Shift solenoid -A (No.1) to -E (No.5) or its cir-
cuit faultyRepair or replace.
Excessive shock at
N
→
→→ → D or N
→
→→ → RShift solenoid -A (No.1), -D (No.4), -E (No.5)
or its circuit faultyRepair or replace.
ISC circuit Inspect ISC circuit.
No lock-up or
No lock-up OFFTCC (lock-up) solenoid valve or its circuit
faultyRepair or replace.
Throttle position sensor or its circuit faulty Refer to “THROTTLE POSITION
SENSOR” in Section 6E.
Input shaft speed and/or output shaft speed
sensor or its circuit faulty.Refer to “ECT SENSOR” in Sec-
tion 6E.
Abnormal engine rev. signal or its circuit. Repair or replace.
ECM faulty Inspect ECM.
AUTOMATIC TRANSMISSION (4 A/T) 7B-19
TABLE 2 (MECHANICAL)
Condition Possible Cause Correction
Vehicle does not move
at any rangeManual valve faulty Clean or replace.
Primary regulator valve faulty Clean or replace.
No gear
change
1st
↔
↔↔ ↔ 2nd
Shift solenoid -D (No.4) and/or -E (No.5)
stuck Clean or replace.
2nd
↔
↔↔ ↔ 3rd
Shift solenoid -A (No.1), -C (No.3) and/or fail
valve No.1 stuckClean or replace.
3rd
↔
↔↔ ↔ 4th
Shift solenoid -B (No.2), -C (No.3) and/or fail
valve No.2 stuckClean or replace.
Harsh engagement
P, N
→
→→ → R
Front clutch accumulator faulty Clean or replace.
N
→
→→ → D
1st & 2nd brake accumulator faulty Clean or replace.
1st
→
→→ → 2nd at D
range or 2 rangeFront clutch accumulator faulty Clean or replace.
Shift solenoid -D (No.4) Clean or replace.
2nd
→
→→ → 3rd at D
rangeDirect clutch accumulator faulty Clean or replace.
Shift solenoid -E (No.5) Clean or replace.
3rd
→
→→ → 4th at D
rangeOverdrive brake accumulator faulty Clean or replace.
Shift solenoid -B (No.2) Clean or replace.
All gear change
Primary regulator valve faulty Clean or replace.
Excessive slip
(low line pressure)Primary regulator valve faulty Clean or replace.
Vehicle does not
move at
1st, 2nd, 3rd and
reverse gearRear clutch faulty Repair or replace.
Reverse gear
Reverse brake faulty Repair or replace.
2nd, 3rd and 4th
gearFront clutch faulty Repair or replace.
3rd and 4th gear
Direct clutch faulty Repair or replace.
1st and 2nd gear
1st & 2nd brake faulty Repair or replace.
4th gear
Overdrive brake faulty Repair or replace.
Any forward and
reverse gearParking lock pawl faulty Repair or replace.
Shock or engine stalls
when starting off and
stoppingTCC (lock-up clutch) faulty Inspect and replace as necessary.
TCC (lock-up) solenoid faulty Clean or replace.
Lock-up control valve faulty Clean or replace.
Lock-up signal valve faulty Clean or replace.
No up-shift
1st
→
→→ → 2nd
Front clutch faulty Repair or replace.
2nd
→
→→ → 3rd
Direct clutch faulty Repair or replace.
3rd
→
→→ → 4th
Overdrive brake faulty Repair or replace.
No engine
braking
2nd or 3rd gear
Front, rear or direct clutch or 1st & 2nd brake
faultyRepair or replace
L range 1st gear
Direct clutch or 1st & 2nd brake faulty Repair or replace.
No lock-up
Torque converter clutch faulty Inspect and replace as necessary.
Lock-up control valve faulty Clean or replace.
TCC (lock-up) solenoid faulty Clean or replace.
Secondary regulator valve faulty Clean or replace.
Signal valve faulty Clean or replace.
7B-20 AUTOMATIC TRANSMISSION (4 A/T)
STALL TEST
This test is to check overall performance of automatic transmis-
sion and engine by measuring stall speed at “D” and “R” ranges.
Be sure to perform this test only when transmission fluid is at nor-
mal operating temperature and its level is between FULL and
LOW marks.
1) Apply parking brake and block wheels.
2) Install tachometer.
3) Start engine with select lever shifted to “P”.
4) Depress brake pedal fully.
5) Shift select lever to “D” and depress accelerator pedal fully
while watching tachometer. Read engine rpm quickly when it
has become constant (stall speed).
6) Release accelerator pedal immediately after stall speed is
checked.
7) In the same way, check stall speed in “R” range.
8) Stall speed should be within following specification.
Stall speed
: 2,750 – 3,150 r/min CAUTION:
Do not run engine at stall more than 5 seconds contin-
uously, for fluid temperature may rise excessively
high.
After performing stall test, be sure to leave engine run-
ning at idle for longer than 30 seconds before another
stall test.
Test result Possible cause
Lower than
standard levelLack of engine output
Defective torque converter
Higher than
standard level
in “D” rangeLow line pressure
Malfunctioning 1st & 2nd brake
Malfunctioning rear clutch
Malfunctioning stator one-way clutch
Higher than
standard level
in “R” rangeLow line pressure
Malfunctioning rear clutch
Malfunctioning reverse brake
Malfunctioning stator one-way clutch
Malfunctioning direct clutch
AUTOMATIC TRANSMISSION (4 A/T) 7B-21
TIME LAG TEST
This test is to check conditions of clutch, reverse brake and fluid
pressure. “Time lag” means time elapsed since select lever is
shifted with engine idling till shock is felt.
1) With chocks placed in front and behind front and rear wheels
respectively, depress brake pedal.
2) Start engine.
3) With stop watch ready, shift select lever from “N” to “D”
range and measure time from that moment till shock is felt.
4) Similarly measure time lag by shifting select lever from “N” to
“R” range.
Specification for time lag
“N”
→
→ → → “D” : Less than 1.0 sec.
“N”
→
→→ → “R” : Less than 1.2 sec.
NOTE:
Make sure that selector cable is properly adjusted.
When repeating this test, be sure to wait at least
minute after select lever is shifted back to “N” range.
Engine should be warmed up fully for this test.
Test result Possible cause
When “N” →
“D”
time lag exceeds specification.Low line pressure
Worn rear clutch
Worn 1st & 2nd brake
When “N” →
“R”
time lag exceeds specification.Low line pressure
Worn rear clutch
Worn direct clutch
Worn reverse brake