2007 ISUZU KB P190 Circuit

TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-153
TCM Input & Output
TCM Voltage Description
The TCM supplies a buffered voltage to various
switches and sensors. The TCM can do this because
resistance in the TCM is so high in value that a test
lamp may not illuminate when connected to the circuit.
An ordinary shop voltmeter may not give an accurate
reading because the voltmeter input impedance is too
low. Use a 10-megaohm input impedance DMM, to
ensure accurate voltage readings. The input and/ or
output devices in the TCM include analog-to-digital
converters, signal buffers, counters, and special
drivers. The TCM controls most components with
electronic switches which complete a ground circuit
when turned ON.
Electrostatic Discharge Damage
Electronic components used in the TCM are often
designed to carry very low voltage. Electronic
components are susceptible to damage caused by
electrostatic discharge. By comparison, as much as
4,000 volts may be needed for a person to feel even
the zap of a static discharge. There are several ways
for a person to become statically charged. The most
common methods of charging are by friction and
induction.
• An example of charging by friction is a person sliding across a vehicle seat.
Important: To prevent possible electrostatic discharge
damage, follow these guidelines:
• Do not touch the TCM connector pins or soldered components on the TCM circuit board.
• Do not open the replacement part package until the part is ready to be installed.
• Before removing the part from the package, ground the package to a known good ground on
the vehicle.
• If the part has been handled while sliding across the seat, while sitting down from a standing
position, or while walking a distance, touch a
known good ground before installing the part.
• Charge by induction occurs when a person with well insulated shoes stands near a highly charged
object and momentarily touches ground. Charges
of the same polarity are drained off leaving the
person highly charged with opposite polarity.
Sensor inputs
Input shaft speed (ISS) sensor
Output shaft speed (OSS) sensor
Transmission fluid temperature (TFT) sensor
Accelerator pedal position signal (via ECM)
Engine speed signal (via ECM)
Switch inputs
Low & reverse brake transmission fulid
pressure (TFP) switch
2-4 brake transmission fulid pressure (TFP)
switch
High clutch transmission fulid pressure (TFP)
switch
Transmission range (TR) switch
Power drive switch
3rd start switch
Brake pedal switch
4WD low gear signal (via TCCM)
TCM
Solenoid valve outputs
Pressure control (PC) solenoid valve
Torque converter clutch (TCC) solenoid valve
Low & reverse brake solenoid valve
2-4 brake solenoid valve
High clutch solenoid valve
Low clutch solenoid valve
Other outputsVehicle speed signal (2WD only)
CommunicationScan tool
Lamp control outputsCheck trans lamp
A/T oil temp. lamp
Power drive lamp
3rd start lamp

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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-155
Legend1. PC solenoid valve
2. Pressure regulator spool valve
3. Spring
4. Line pressure from oil pump
5. Solenoid fluid pressure
6. Line pressure in forward range 7. Adjusted line pressure
8. Drain
9. PC solenoid valve commanded ON
10. PC solenoid valve commanded OFF 11. Adjusted line pressure in P, N or R range
12. Adjusted line pressure in forward range
The TCM drives the ON/ OFF type pressure control
(PC) solenoid valve based on the accelerator pedal
angle, input shaft speed, output shaft speed,
transmission fluid temperature and transmission range
signal.
The line pressure generated by the oil pump acts on
the point A of the pressure regulator spool valve. When
the PC solenoid valve is turned ON by the signal from
the TCM, the solenoid fluid pressure does not act. The
line pressure is adjusted to match the spring force
acting on the right side of the pressure regulator spool
valve. When the PC solenoid valve is turned OFF, the
solenoid fluid pressure acts so that the line pressure is
adjusted to match the spring force acting on the right
side of the pressure regulator spool valve. As a result,
the line pressure is adjusted to be low when the PC
solenoid valve is ON and to be high when the PC
solenoid valve is OFF. In position D, 3, 2 and L, the line
pressure through the oil pressure circuit acts onto the
point B of the pressure regulator spool valve. The
pressure regulator valve moves so as to increase the
pressure to be drained, so that the line pressure is
adjusted to be lower than the P, N, and R position by
the difference of area at the point B.
11
7
12
4
6 B
A 2
7 8 3 1
5
910

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ISUZU KB P190 2007

7A3-4 ON-VEHICLE SERVICE (JR405E)



RTW 07ASH000101

Inspect
1. Check the drain plug tip for adhesion of foreign
substances.
2. Check the drained ATF for color, smell and inclusion of foreign substances.
3. Check the oil pan bottom and magnet for adhesion o
f
foreign substances.
If a problem is discovered during those checks, the Automatic transmission must be overhauled.
Note:
The torque converter and the oil strainer need replacing
with new ones if the drained ATF contains large
amounts of metallic or facing flakes.
In addition, flush the ATF cooler circuit.





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ISUZU KB P190 2007

7A3-8 ON-VEHICLE SERVICE (JR405E)
SPEED SENSOR
The speed sensor is attached to the right side of the
transmission.
240L300001
Legend
1. Inhibitor switch
2. Speed sensor
3. Turbine sensor


Inspect
1. During driving at a speed of 20km/h (12mph) with “L”
range in low gear, measure the voltage between the
TCM connector terminals (B13) and (B5) with a
digital voltmeter.
Standard voltage : approx. 7V (AC range)






RTW 47ASH000801
2. If the voltage is outside of the standard value, check
the speed sensor pole piece for the presence o
f
foreign materials and the speeed sensor cable for a
short or open circuit.
If the result of the inspection is normal, replace the speed sensor.
Torque: 6 N·m (0.6 kgf·m/52 lb·in)



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ISUZU KB P190 2007

ON-VEHICLE SERVICE (JR405E) 7A3-9
TURBINE SENSOR
The turbine sensor is attached to the right side of the
transmission.

Inspect
1. During driving at a speed of 20km/h (12mph) with “L” range in low gear, measure the voltage between the
TCM connector terminals (B3) and (B5) with a digital
voltmeter.
Standard voltage : approx. 7V (AC range)
2. If the voltage is outside of the standard value, check the turbine sensor pole piece for presence of foreign
materials and the turbine sensor cable for a short o
r
open circuit.
If the result of the inspection is abnormal, replace the turbine sensor.
Torque: 6 N·m (0.6 kgf·m/52 lb·in)



POWER AND 3RD START SWITCH
Inspect
1. Block the wheels.
2. Disconnect the negative battery cable.
3. Pry out the switch from the floor console.
4. Disconnect the harness connector.
5. Check continuity between terminals (5) and (6) at third (3rd) position.
6. Check continuity between terminals (3) and (6) at power (PW R) position.
7. Replace the power and 3rd start switch if the result o
f
inspection is abnormal.
8. Connect the harness connector.
9. Connect the negative battery cable.
10. Remove the wheel blocks.
238R300003



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ISUZU KB P190 2007

ON-VEHICLE SERVICE (JR405E) 7A3-19
Install or Connect
1. Align the manual valve and the manual plate of the
transmission case.
43ASSY119
2. Install the control valve assembly and tighten the 12 fixing bolts to the specified torque.
Number of bolts Length Color
10 (A) 40 mm (1.57 in) Gold
2 (B) 30 mm (1.18 in) Gold

Bolt torque : 8 N·m (0.8 kgf·m/69 lb·in)
3. Connect the 2 harness connectors.
4. If removed, install the oil strainer.
Refer to “Solenoids, Oil Pressure Switch and Oil Temperature Sensor” previously in this section.
5. Install the new gasket and oil pan.
Bolt torque : 8 N·m (0.8 kgf·m/69 lb·in)
6. Fill with the fluid.
Refer to “ATF CHANGE” in this section.
7. Connect the negative battery cable.
8. Remove the wheel blocks.

FLUSHING THE TRANSMISSION FLUID COOLER AND LINE
The fluid cooler and lines may be flushed under the
following condition. This will help prevent more trouble
after the transmission is repaired.
1. W hen an abnormal amount of debris is found.
2. W hen an abnormal wear or chips on gears and shafts is found while overhauling.
3. W hen there is abnormal clutch facing wear and oil contamination found.

Procedures
1. Block the wheels.
2. Disconnect the negative battery cable.
3. Raise the vehicle and support it with suitable safet
y
stands.
4. Disconnect the fluid cooler lines at the transmission case and fluid cooler.
5. Flush and back-flush the fluid cooler and lines using solvent and compressed air.
Note:
DO NOT exceed (200 kPa/2.0 kgf/cm
2/28 psi) air
pressure, or damage may result to oil cooler.

6. Remove all remaining solvent from the system with
compressed air.
7. Flush the cooling system again with Automatic Transmission Fluid (ATF).
After the final flush, connect all lines.
Cooler line joint connector torque :
44 N·m (4.5 kgf·m/33 lb·ft)
8. Replenish the ATF.
9. Start the engine to test the system for the free flow o
f
fluid. If the flow is restricted, the cooler assembly o
r
lines must be replaced.
Repeated cleaning and flushing may not remove all the debris from the fluid cooler circuit.
Move the select lever through the various ranges and return to neutral.
Check for fluid level.
If the fluid level is below the specified range, ATF must be added.
10. Connect the negative battery cable.
11. Remove the safety stands.
12. Remove the wheel blocks.

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ISUZU KB P190 2007

CLUTCH 7C-45
2. CLUTCH DOES NOT RELEASE PROPERLY

Checkpoint Problem Countermeasure


Adjust the push rod play

Too much push rod play in the
master cylinder

NG
Clutch pedal free play

Driven plate

Replace the driven plate

Driven plate warped or
unevenly worn


Hydraulic circuit

Bleed the hydraulic circuit

Air in the hydraulic circuit

OK
NG
NG
OK
Clean or repair the top gear
shaft spline
Replace the top gear shaft
Corrosion or step wear on the
top gear shaft spline


Pressure plate

Replace the pressure plate
assembly


Clean and grease the splined
contact surface


Pressure plate unevenly worn

Insufficient grease on the
spline contact surface of the
splined hub
OK NG
NG
NG
OK
Continued on the next page


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ISUZU KB P190 2007

TRANSFER CONTROL SYSTEM 7D1-1
SECTION 7D1
TRANSFER CONTROL SYSTEM
TABLE OF CONTENTS
PAGE
Service Precaution ..................................................................................................... 7D1 - 2
General Description ................................................................................................... 7D1 - 3
System Components .................................................................................................. 7D1 - 5 Parts Location ....................................................................................................... 7D1 - 5
Functions of Switch and Indicator Lamp ................................................................. 7D1 - 12
Parts Location ............................................................................................................ 7D1 - 24
Circuit Diagram ........................................................................................................... 7D1 - 33
Connector List ............................................................................................................ 7D1 - 41
Diagnosis .................................................................................................................... 7D1 - 46
Before determining a trouble (Non-trouble mode) ............................................ 7D1 - 46
Memory erasing procedure ....................................................................................... 7D1 - 52
Diagnosis from symptom ........................................................................................... 7D1 - 54




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ISUZU KB P190 2007