2007 ISUZU KB P190 brake fluid

7A2-16 TRANSMISSION CONTROL SYSTEM (JR405E)
Transmission Fluid Passages (Main Unit)
Legend1. Oil cooler (outlet)
2. Low & reverse brake pressure detection port (R range line pressure detection port)
3. Low clutch pressure detection port (D, 3, 2, L range
line pressure detection port)
4. High clutch pressure detection port
5. 2-4 brake pressure detection port
6. Oil cooler (inlet)
7. Oil cooler (outlet)
8. High clutch pressure detection passage
9. Oil pump passage (outlet)
10. Reverse clutch passage 11. High clutch passage 12. Front lubrication passage
13. 2-4 brake passage
14. Oil pump passage (inlet)
15. Torque converter passage (when not in lock up
control)
16. Torque converter passage (when in lock up control)
17. Oil cooler passage (inlet)
18. 2-4 brake pressure detection passage
19. Extension lubrication passage
20. Low clutch passage
21. Rear lubrication passage
22. Low & reverse brake passage
23. Low & reverse brake pressure detection passage

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ISUZU KB P190 2007

7A2-24 TRANSMISSION CONTROL SYSTEM (JR405E)
Scan Tool Data List
The Transmission Scan Tool Data List contains all
transmission related parameters that are available on
the scan tool. Use the Transmission Scan Tool Data
List only after the following is determined:
• The Transmission Controls - Diagnostic System Check is completed. • On-board diagnostics are functioning properly.
Scan tool values from a properly running engine may
be used for comparison with the transmission you are
diagnosing. The Transmission Scan Tool Data List
represents values that would be seen on a normal
running engine. Only the parameters listed below are
referenced in this service manual for use in diagnosis.
Scan Tool Parameter Units DisplayedTypical Data
Operating Conditions: Engine idle/ Engine coolant temperature is between 75 to 85 °C (167 to 185 °F)/ Accelerator pedal is not
pressed/ Park range/ Transfer case is 2H position/ Accessories OFF
Accelerator Pedal Position %0%
Engine Speed RPMNearly 700 RPM
AT Input Speed (Automatic Transmission) RPM600 to 700 RPM
TCC Slip Speed (Torque Converter Clutch) RPMLess than 100 RPM
AT Output Speed (Automatic Transmission) RPM0 RPM
Vehicle Speed km/h/ MPH0 km/h / MPH
Current Gear 1st/ 2nd/ 2nd L-Up/ 3rd/ 3rd
L-Up/ 4th/ 4th L-Up 1st
Estimated Gear Ratio : 132.77:1
Transmission Range (TR) Park/ Neutral/ Reverse/
Drive/ Drive 3/ Drive 2/ Drive 1 Park
TR Switch P (Transmission Range) On/ OffOn
TR Switch R (Transmission Range) On/ OffOff
TR Switch N (Transmission Range) On/ OffOff
TR Switch D (Transmission Range) On/ OffOff
TR Switch 3 (Transmission Range) On/ OffOff
TR Switch 2 (Transmission Range) On/ OffOff
TR Switch L (Transmission Range) On/ OffOff
PCS Command (Pressure Control Solenoid) On/ OffOn
Low & Reverse Brake Solenoid Command %100%
Low & Reverse Brake Pressure Switch On/ OffOff
2-4 Brake Solenoid Command %100%
2-4 Brake Pressure Switch On/ OffOff
High Clutch Solenoid Command %100%
High Clutch Pressure Switch On/ OffOff
Low Clutch Solenoid Command %0%
TCC Solenoid (Torque Converter Clutch) %5%
Transmission Fluid Temperature °C/ °F V arie s
Transmission Oil Temperature Lamp On/ OffOff
TCM Status Temp. (Temperature Transmission Control Module) Low/ HighLow
4 Wheel Drive Low On/ OffOff
TCM Status Transfer (Transmission Control Module) Low/ HighHigh
TCM Status Down Slope (Transmission Control Module) On/ OffOff

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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-25
Scan Tool Data Definitions
This information will assist in driveability problems. The
displays can be viewed while the vehicle is being
driven. Always perform the Diagnostic System Check -
Transmission Controls first. The Diagnostic System
Check will confirm proper system operation.
Accelerator Pedal Position
This parameter displays the angle of the accelerator
pedal as calculated by the engine control module
(ECM) using the signals from the accelerator pedal
position (APP) sensors. This data is sent over the pulse
wave modulation (PWM) signal from the ECM to the
TCM. The scan tool will display linearly from 0 to 100%
according to the pedal operation.
Engine Speed
This parameter displays the rotational speed of the
crankshaft as calculated by the engine control module
(ECM) based on inputs from the crankshaft position
sensor or camshaft position sensor. This data is sent
over the pulse signal from the ECM to the TCM.
AT Input Speed (Automatic Transmission)
This parameter displays the rotational speed of the
reverse & high clutch drum as calculated by the TCM
based on inputs from the input shaft speed (ISS)
sensor.
TCC Slip Speed (Torque Converter Clutch)
This parameter displays the difference between
transmission input shaft speed and the engine speed
(engine speed - input shaft speed). A negative value
indicates that the engine speed is less than the input
shaft speed, deceleration. A positive value indicates
that the engine speed is greater than the input shaft
speed, acceleration. A value of zero indicates that the
engine speed is equal to the input shaft speed, torque
converter clutch (TCC) is applied.
AT Output Speed (Automatic Transmission)
This parameter displays the rotational speed of the
parking gear that is connected to the output shaft as
calculated by the TCM based on inputs from the output
shaft speed (OSS) sensor. Vehicle Speed
This parameter indicates the vehicle speed calculated
by the TCM using the signal from the output shaft
speed sensor. The scan tool will display a low value at
lower vehicle speeds, and a high value at higher
vehicle speeds.
Current Gear
This parameter displays the current gear position
based on the command from the TCM.
Estimated Gear Ratio
This parameter displays the current gear ratio
calculated by the TCM using the signal from the input
shaft speed (ISS) sensor and the output speed sensor
(OSS) sensor.
Transmission Range (TR)
This parameter displays the selector lever position
based on the transmission range (TR) switch inputs.
TR Switch P, R, N, D, 3, 2, L (Transmission Range)
This parameter displays the input state of the
transmission range (TR) switch to the TCM. When the
selector lever is moved to each range, the scan tool
displays On.
PCS Command (Pressure Control Solenoid)
This parameter displays the commanded state of the
pressure control (PC) solenoid valve control circuit. On
indicates the solenoid valve is being energized by the
TCM, allowing line pressure to be low.
Low & Reverse Brake Solenoid Command
This parameter displays the low & reverse brake
solenoid valve control duty ratio based on the
command for the TCM. The scan tool will display a
lower percentage when the low & reverse brake is
controlled to engage (fluid pressure is applied to the
low & reverse brake hydraulic circuits). The scan tool
will display higher percentage when the low & reverse
brake is controlled to disengage (fluid pressure is
drained from the low & reverse brake hydraulic
circuits).
TCM Status Up Slope (Transmission Control Module) On/ OffOff
3rd Start Switch On/ OffOff
3rd Start Lamp On/ OffOff
Power Drive Switch On/ OffOff
Power Drive Lamp On/ OffOff
Brake Pedal Switch On/ OffOff
Diagnostic Switch On/ OffOff
Check Trans Lamp On/ OffOff
Scan Tool Parameter
Units DisplayedTypical Data

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ISUZU KB P190 2007

7A2-26 TRANSMISSION CONTROL SYSTEM (JR405E)
Low & Reverse Brake Pressure Switch
This parameter displays the input state of the low &
reverse brake transmission fluid pressure (TFP) switch
to the TCM. When the low & reverse brake fluid
pressure is generated, the scan tool displays On.
2-4 Brake Solenoid Command
This parameter displays the 2-4 brake solenoid valve
control duty ratio based on the command from the
TCM. The scan tool will display a lower percentage
when the 2-4 brake is controlled to engage (fluid
pressure is applied to the 2-4 brake hydraulic circuits).
The scan tool will display higher percentage when the
2-4 brake is controlled to disengage (fluid pressure is
drained from the 2-4 brake hydraulic circuits).
2-4 Brake Pressure Switch
This parameter displays the input state of the 2-4 brake
transmission fluid pressure (TFP) switch to the TCM.
When the 2-4 brake fluid pressure is generated, the
scan tool displays On.
High Clutch Solenoid Command
This parameter displays the high clutch solenoid valve
control duty ratio based on the command from the
TCM. The scan tool will display a lower percentage
when the high clutch is controlled to engage (fluid
pressure is applied to the high clutch hydraulic circuits).
The scan tool will display higher percentage when the
high clutch is controlled to disengage (fluid pressure is
drained from the high clutch hydraulic circuits).
High Clutch Pressure Switch
This parameter displays the input state of the high
clutch transmission fluid pressure (TFP) switch to the
TCM. When the high clutch fluid pressure is generated,
the scan tool displays On.
Low Clutch Solenoid Command
This parameter displays the low clutch solenoid valve
control duty ratio based on the command from the
TCM. The scan tool will display a lower percentage
when the low clutch is controlled to engage (fluid
pressure is applied to the low clutch hydraulic circuits).
The scan tool will display higher percentage when the
low clutch is controlled to disengage (fluid pressure is
drained from the low clutch hydraulic circuits).
TCC Solenoid (Torque Converter Clutch)
This parameter displays the torque converter clutch
(TCC) control duty ratio based on the command from
the TCM. The scan tool will display a lower percentage
when the TCC is controlled to disengage (fluid
pressure is drained from the TCC release hydraulic
circuits). The scan tool will display higher percentage
when the TCC is controlled to engage (fluid pressure is
applied to the TCC apply hydraulic circuits). Transmission Fluid Temperature
This parameter displays the temperature of the
automatic transmission fluid (ATF) temperature as
calculated by the TCM using the signal from the
transmission fluid temperature (TFT) sensor. The scan
tool will display a low temperature when the signal
voltage is high, and a high temperature when the signal
voltage is low.
Transmission Oil Temperature Lamp
This parameter displays the commanded state of the
transmission oil temperature lamp control circuit. The
lamp should be On when the scan tool indicates
command On.
TCM Status Temp. (Temperature Transmission
Control Module)
This parameter displays the commanded state of the
high temperature mode shift map. On indicates the
transmission fluid temperature is high and the high
temperature mode is selected to prevent an
overheating.
4 Wheel Drive Low
This parameter displays the input state of the 4WD low
gear signal from the transfer case control module
(TCCM). When the 4L mode is selected, the scan tool
displays On.
TCM Status Transfer (Transmission Control
Module)
This parameter displays the commanded state of the
shift map that is based on the transfer case position.
High indicates the high mode (2H or 4H) is inputted
from the transfer case control module (TCCM). Low
indicates the low mode (4L) is inputted from the TCCM.
TCM Status Down Slope (Transmission Control
Module)
This parameter displays the commanded state of the
down slope mode shift map. On indicates the down
slope mode is selected under certain driving conditions.
TCM Status Up Slope (Transmission Control
Module)
This parameter displays the commanded state of the
up slope mode shift map. On indicates the up slope
mode is selected under certin driving conditions.
3rd Start Switch
This parameter displays the input state of the 3rd start
switch to the TCM. When the switch is pressed, the
scan tool displays On.
3rd Start Lamp
This parameter displays the commanded state of the
3rd start lamp control circuit. The lamp should be On
when the scan tool indicates command On.

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7A2-52 TRANSMISSION CONTROL SYSTEM (JR405E)
DTC P0731, P0732, P0733 or P0734 (Flash Code 41, 42, 43 or 44)
Circuit Description
The TCM calculates the gear ratio based on the input
shaft speed signal from the input shaft speed (ISS)
sensor and the output speed signal from the output
shaft speed (OSS) sensor. The TCM compares the
known transmission gear ratio to the calculated ratio for
the selected gear ranges. If the TCM detects an
unknown transmission gear ratio two consecutive
driving cycles, this DTC will set.
Condition for Running the DTC • Other than DTCs P0731, P0732, P0733 and P0734 are not set.
• The ignition switch is ON.
• The transmission fluid temperature is more than 60 °C (140 °F).
• The input shaft speed is more than 1000 RPM.
• The vehicle speed is more than 10 km/h (6 MPH).
• The selector lever is forward range for longer than 2 seconds.
• The TCM is not under gearshift control.
Condition for Setting the DTC • The TCM detects that the output shaft speed is more than 500 RPM over the calculated speed
(based on the input shaft speed and the gear ratio)
for 7 seconds after each gearshift has completed.
Action Taken When the DTC Sets • The TCM blinks the Check Trans lamp on the second consecutive driving cycle when the
diagnostic runs and fails.
Condition for Clearing the DTC • The TCM turns OFF the Check Trans lamp when the diagnostic runs and does not fail. • A current DTC clears when the diagnostic runs and
does not fail.
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
• Electromagnetic interference in the ISS sensor or OSS sensor circuits may set this DTC.
• An intermittent ISS sensor or OSS sensor signal pulse may set this DTC.
• Ensure the ISS sensor and OSS sensor is tight.
• Use the Clutch, Brake, Solenoid and Pressure Switch Logic table to verify each component works
properly within the selected gear range.
• A transmission mechanical problem will cause this DTC to set.
• Sticking or contamination of shift valves may cause intermittent incorrect gear ratios.
• If multiple incorrect gear ratio codes are set, problem in fluid pressure, low ATF level, plugged
filter or oil pump problem may exist.
Notice: • Each DTC agrees with the following gear positions.
- P0731: 1st gear
- P0732: 2nd gear
- P0733: 3rd gear
- P0734: 4th gear
Schematic Reference: Transmission Controls
Schematics
Connector End View Reference: Transmission
Controls Connector End Views or TCM Connector End
Views
Circuit/ System Testing DTC P0731, P0732, P0733 or P0734
Step Action Value(s)Yes No
1 Did you perform the Diagnostic System Check -
Transmission Controls? —
Go to Step 2 Go to Diagnostic
System Check - Transmission Controls
2 Perform the ATF level check. Refer to repair
instructions (On-Vehicle Service).
Did you perform the ATF level check? —
Go to Step 3 Go to Transmission
Fluid Checking Procedure
3 1. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Drive the vehicle while observing the DTC Information with a scan tool.
Is there any DTCs set other than P0731, P0732,
P0733 or P0734? —
Refer to Applicable DTC Go to Step 4

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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-53
41. Inspect all of the circuits going to the input
shaft speed (ISS) sensor and the output shaft
speed (OSS) sensor for the following
conditions:
• Routed too closely to fuel injection wiring or components
• Routed too closely to after-market add- on electrical equipment
• Routed too closely to solenoids and relays
2. If you find incorrect routing, correct the harness routing.
Did you find and correct the condition? —
Go to Step 13 Go to Step 5
5 1. Disconnect the ISS sensor and the OSS
sensor harness connector.
2. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the ISS sensor (pins 1, 2 and 3 of
E-31) and the OSS sensor (pins 1,2 and 3 of
E-30).
3. Disconnect the TCM harness connector.
4. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the TCM (pins 3 and 13 of C-95).
5. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 6
6 1. Inspect the ISS sensor and the OSS sensor
for the following conditions:
• Physical damage of sensor
• Loose or improper installation of sensor
• Excessive air gap
• Foreign material passing between ISS sensor and reverse & high clutch drum
• Foreign material passing between OSS sensor and parking gear
• Physical damage of reverse & high clutch drum or parking gear
2. Repair or replace as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 7
7 1. Place the selector lever in D range.
2. Observe the Low & Reverse Brake Pressure Switch, 2-4 Brake Pressure Switch and High
Clutch Pressure Switch parameter with a scan
tool. Refer to Clutch, Brake, Solenoid and
Pressure Switch Logic table.
Does the each transmission fluid pressure (TFP)
switch display match each selected gear range? —
Go to Step 8 Refer to DTC
P1853, P1858 or P1863
8 Perform the line pressure test. Refer to Line
Pressure Test.
Is the line pressure within specifications for each
selected gear range? —
Go to Step 9 Refer to appropriate
instructions in the
Line Pressure Test
Step
Action Value(s)Yes No

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7A2-54 TRANSMISSION CONTROL SYSTEM (JR405E)
91. Remove the transmission oil pan. Refer to
repair instruction (On-Vehicle Service).
2. Inspect the oil pan and the fluid for contamination.
Was excessive contamination found? —
Replace the
transmission fluid
and filter and Go to Step 10 Go to Step 11
10 Drive the vehicle while observing the DTC
Information with a scan tool.
Does the DTC fail this ignition? —
Go to Step 11 Go to Step 13
11 1. Remove the all shift solenoid valve and all
TFP switch from the valve body assembly and
perform function check. Refer to repair
instructions (On-Vehicle Service).
2. Repair or replace as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 12
12 Repair or replace the valve body assembly/
clutches or brakes (On-Vehicle Service or Unit
Repair).
Did you complete the repair or replacement? —
Go to Step 13 —
13 1. Reconnect all previously disconnected
components or harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Drive the vehicle while observing the DTC Information with a scan tool.
Did the DTC fail this ignition? —
Go to Step 2 Go to Step 14
14 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK
Step
Action Value(s)Yes No

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ISUZU KB P190 2007

7A2-58 TRANSMISSION CONTROL SYSTEM (JR405E)
DTC P0753 (Flash Code 31)
Circuit Description
The low & reverse brake solenoid valve controls fluid
acting on spool valves in the low & reverse brake
hydraulic circuits, which then controls low & reverse
brake apply and release. The solenoid valve is installed
to the lower part of the valve body assembly. The TCM
controls the solenoid valve by a duty cycle (pulse width
modulation [PWM]) signal based on the commanded
gear position. The solenoid valve provides a smooth
gearshift by operating on a duty cycle percentage of
ON time. The TCM monitors the low & reverse brake
solenoid valve operating status through the feedback
circuit. If the TCM detects an improper voltage level on
the control circuit, this DTC will set.
Condition for Running the DTC • The ignition switch is ON.
Condition for Setting the DTC • The TCM detects an open circuit or short circuit on the low & reverse brake solenoid valve control
circuit.
Action Taken When the DTC Sets • The TCM blinks the Check Trans lamp when the diagnostic runs and fails.
During the vehicle running;
• The TCM holds the last gear position when the diagnostic runs and fails. • The TCM stops low & reverse brake solenoid
valve.
• The TCM inhibits lock up control.
After the vehicle stopped;
• The TCM stops all shift solenoid valves and fixes to the 3rd gear. If a fail-safe valve problem is
detected, the shift solenoid valves are not stopped
but gear is fixed to the 3rd gear.
• The TCM stops PC solenoid valve.
Condition for Clearing the DTC • The TCM turns OFF the Check Trans lamp when the diagnostic runs and does not fail at next
ignition cycle.
• A current DTC clears when the diagnostic runs and does not fail at next ignition cycle.
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
• Use the Clutch, Brake, Solenoid and Pressure Switch Logic table to verify each component works
properly within the selected gear range.
Schematic Reference: Transmission Controls
Schematics
Connector End View Reference: Transmission
Controls Connector End Views or TCM Connector End
Views
Circuit/ System Testing DTC P0753
Step Action Value(s)Yes No
1 Did you perform the Diagnostic System Check -
Transmission Controls? —
Go to Step 2 Go to Diagnostic
System Check - Transmission Controls
2 1. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Lift the driving wheels or drive the vehicle while observing the DTC Information with a
scan tool.
Is DTC P1875 also set? —
Go to DTC P1875 Go to Step 3
3 1. Park the vehicle.
2. Turn ON the ignition, with the engine OFF.
3. Perform the Low & Reverse Brake Solenoid control with a scan tool.
4. Command the solenoid valve ON and OFF.
Does the low & reverse brake solenoid valve click
with each command? —
Go to Diagnostic Aids Go to Step 4

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ISUZU KB P190 2007