1999 SUZUKI GRAND VITARA ecm

YH4
GRAND
VITARA
7B1-8 AUTOMATIC TRANSMISSION (4 A / T)
G16 / J20 Engines
1. PCM (ECM)
2. VSS
3. CMP sensor
4. TP sensor
5. ECT sensor
6. A / T input speed sensor
7. A / T output speed sensor
8. Transmission range switch9. Shift solenoid-A
10. Shift solenoid-B
11. TCC solenoid
12. Data link connector
13. Cruise control module
14. ªPOWERº lamp
15. ªO / D OFFº lamp
16. MIL17. O / D cut switch
18. P / N change switch
19. 4WD low switch
20. Main relay
21. Ignition switch
22. Battery
23. PCM (ECM) connector terminal
(viewed from harness side) Bl / Y
Bl / G
W
OrC51-1-11
C51-1-10
C51-1-23
C51-1-22
12V

YH4
GRAND
VITARA
AUTOMATIC TRANSMISSION (4 A / T) 7B1-9
H25 Engine
1. PCM (ECM)
2. VSS
3. CMP sensor
4. TP sensor
5. ECT sensor
6. Brake pedal switch
7. A / T input speed sensor
8. A / T output speed sensor9. Transmission range switch
10. Shift solenoid-A
11. Shift solenoid-B
12. TCC solenoid
13. Data link connector
14. Cruise control module
15. ªPOWERº lamp
16. ªO / D OFFº lamp17. MIL
18. O / D cut switch
19. P / N change switch
20. 4WD low switch
21. Main relay
22. Ignition switch
23. Battery
24. PCM (ECM) connector terminal
(viewed from harness side) Bl / Y
Bl / G
W
OrC51-1-16
C51-1-8
C51-1-10
C51-1-9
12V

YH4
GRAND
VITARA
1. Monitor connector
AUTOMATIC TRANSMISSION (4 A / T) 7B1-17
AUTOMATIC TRANSMISSION 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 transmission including this system, be sure to have full understanding of the outline
of ªOn-board Diagnostic Systemº and each item in ªPrecaution in Diagnosing Troubleº and execute diagnosis ac-
cording to ªAUTOMATIC TRANSMISSION DIAGNOSTIC FLOW TABLEº given below to obtain correct result
smoothly.
NOTE:
There are two types of ON-BOARD DIAGNOSTIC SYSTEM de-
pending on vehicle specifications. The type of system for ve-
hicle being serviced can be identified by whether equipped
with monitor connector or not.

YH4
GRAND
VITARA
1. Malfunction indicator lamp (MIL)
2. Scan tool
3. DLC
7B1-18 AUTOMATIC TRANSMISSION (4 A / T)
[For Vehicle without Monitor Connector]
ON-BOARD DIAGNOSTIC SYSTEM
For automatic transmission control system, PCM (ECM) has follow-
ing 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 malfunction in A / T control system (and / or
a malfunction which gives an adverse effect to vehicle emission)
while the engine is running, it makes the malfunction indicator
lamp in the meter cluster of the instrument panel turn ON and
stores the malfunction area in its memory. (If it detects that contin-
uously 3 driving cycles are normal after detecting a malfunction,
however, it makes MIL turn OFF although DTC stored in its
memory will remain.)

It is possible to communicate through DLC by using not only SU-
ZUKI scan tool (Tech-1) but also generic scan tool. (Diagnostic in-
formation can be accessed by using a scan tool.)
2 Driving Cycle Detection Logic
Refer to section 6 / 6-1 for details.
Pending DTC
Refer to section 6 / 6-1 for details.
Freeze Frame Data
Refer to section 6 / 6-1 for details.

YH4
GRAND
VITARA
1. Malfunction indicator lamp (MIL)
2. Scan tool
3. DLC
4. Monitor connector
5. Diagnosis switch terminal
6. Ground terminal MIL
OFF
Time (sec.)
AUTOMATIC TRANSMISSION (4 A / T) 7B1-19
[For Vehicle with Monitor Connector]
ON-BOARD DIAGNOSTIC SYSTEM
For automatic transmission control system, PCM (ECM) has follow-
ing 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 system, it
stores its trouble code in back-up memory in itself. (The memory
is kept as it is even if the trouble was only temporary and disap-
peared 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 SU-
ZUKI scan tool (Tech-1) but also generic scan tool. (Diagnostic in-
formation can be accessed by using a scan tool.)

It is also possible to communicate by not using scan tool. PCM
indicates trouble area in memory by means of flashing of malfunc-
tion indicator lamp at the time of inspection (i.e. when diagnosis
switch terminal is grounded and ignition switch is turned ON).

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
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.