
Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–103
Step Action Yes No
6 Using a multimeter, test between E-95 pin 3 and C-96 pin 30 for a
short to voltage.
Did you find and correct the condition? Go to Step 8 Go to Step 7
7 Replace the TCM, refer to 7C4 Automatic Transmission – 4L60E –
On-vehicle Servicing
Did you complete the replacement? Go to Step 8 —
8 Perform the following procedure to verify the repair:
1 On Tech 2 select: Diagnostic Trouble Codes / Clear Engine & Transmission
DTCs.
2 Follow the instructions on Tech 2 and clear any DTCs.
3 On Tech 2 select: Data Display / 2-3 Shift Data.
4 Drive the vehicle in D4 and ensure the following conditions are met::
• The TCM commands the Shift Solenoid B On and the
Shift Solenoid B Circuit status parameter displays Okay.
• The TCM commands the Shift Solenoid B Off and the
Shift Solenoid B Circuit status parameter displays Okay.
• All conditions are met for 5 seconds.
4 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0977 set? Go to Step 2 Go to Step 9
9 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Does Tech 2 display any DTCs you have not diagnosed? Refer to
4.8 Diagnostic Trouble Code List System OK
When all diagnosis and repairs are completed, check the
system for correct operation.
4.32 DTC P1810, P1815 and P1816 –
Transmission Fluid Pressure Position
Switch
DTC Description
This diagnostic procedure supports the following DTCs:
• DTC P1810 Transmission Fluid Pressure (TFP) Position Switch Circuit.
• DTC P1815 Transmission Fluid Pressure (TFP) Valve Position Switch – Start in W rong Range.
• DTC P1816 Transmission Fluid Pressure (TFP) Valve Position Switch Indicates Park/Neutral (P/N) with Drive Ratio.
Circuit Description
The automatic transmission fluid pressure (TFP) manual valve position switch consists of five pressure switches
(two normally-closed and three normally-open) and a transmission fluid temperature (TFT) sensor combined into one unit.
The combined unit mounts on the valve body. The transmission control module (TCM) supplies ignition voltage for each
range signal. By grounding one or more of these circuits through various combinations of the pressure switches, the
TCM detects which manual valve position you select. The TCM compares the actual voltage combination of the switches
to a TFP manual valve position switch combination chart stored in memory.
The TFP manual valve position switch cannot distinguish between park and neutral because the monitored valve body
pressures are identical. W ith the engine off and the ignition switch on, the TFP manual valve position switch indicates
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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-13
Item Description
Reverse lock out control If the select lever is moved to "R" position during forward driving, the TCM prohibits
reverse driving by turn off the S1 and turn on the S2 for prevention of danger and
protection of the automatic transmission.
1. Enable condition a) Vehicle speed is more than 11km/h (7mph).
2. Disable condition a) Vehicle speed is less than 9km/h (6mph).
b) W hen except "R" position is detected.
Auto cruise mode control If the auto cruise control can’t keep the setting speed like a uphill driving, the TCM selects the auto cruise mode shift pattern for downshifting, thus keeping the vehicle
speed.
W arm-up mode control TCM selects the warm-up mode shift pattern in engine cold condition for improvement of drivability and facilitation of warm-up.
Squat control W hen the TCM detects N→D garage shift, the TCM controls 1-3-1 shift by setting
timer, in order to improve the shift feel at N →D.
Coast down control The TCM switches to the coast down control at the coasting, in order to reduce the
roughness of shifting.
Uphill control W hen the TCM detected uphill, the TCM automatically switches to the uphill mode
in two-stage in proportion to inclination pitch to prevent the busy shifting and to
obtain an enough torque.
Downhill control W hen the TCM detected downhill, the TCM automatically switches to the downhill
mode, and shifts to the 3rd or keeps in the 3rd in order to prevent the vehicle
acceleration. Then, the brake load is reduced by a moderate engine brake and fuel
consumption is improved by the fuel cut.
Line pressure control The TCM controls the impressed current of the pressure control solenoid based on the throttle opening, and regulates suitable throttle pressure.
Engine truque management
control The TCM controls engine torque for improvement of shift quality or durability under
the following conditions.
• Upshift and downshift
• Garageshift
Indicate driving mode function The TCM indicates the following driving mode on instrument panel.
• Power mode
• 3rd start mode
Indicate oil temperature
warning function If the transmission oil temperature sensor senses that transmission oil temperature
is greater than 146 °C (295 °F) , the TCM turns on ATF warning lamp. (The warning
lamp is turned off, if oil temperature is less than 126 °C/ 259 °F .)
Fail-safe function W hen trouble occurs to vehicle sensor and each solenoid, TCM automatically exerts
fail-safe control not to spoil driveability.
• This control is exerted when sensor or actuator is in trouble, while TCM works
normally.
• The "CHECK TRANS" light flashes to alert the driver, and the transmission
must be manually shifted as follows.
Select lever position Gear position
D 4 (Fourth)
3 4 (Fourth)
2 3 (Third)
L 3 (Third)
R Reverse
Shift are firmer to prevent clutch slip and consequent wear. The fault should be
corrected as soon as possible.
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7A2-46 TRANSMISSION CONTROL SYSTEM (AW30–40LE)
(2) Not emergency mode.
(3) All of the following conditions are met. • Device Control is not operating.
• Disable Normal Communication service is
receiving enable.
• DTC Clear is not operating.
Condition For Setting The DTC
DTC P0707
All of the following conditions are met for 30 seconds or
more continuously.
• All of the switches are “OFF”.
• Output revolution is more than 30 km/h (19 mph).
• Output revolution sensor is not detecting failure o
r
not deciding failure.
• The engine revolution is more than 1500 rpm.
DTC P0708
The following condition is met at 10 seconds
continuously.
• 2 switches or more are “ON” at the same time.
Action Taken When The DTC Sets
• No 3rd start mode.
• No slope control.
• No coast control.
• No output revolution sensor failure detection.
• No input revolution sensor failure detection.
• Keep oil temperature sensor OPEN failure detection accumulated timer.
• No T/F HI-Low SW failure detection.
• No shift solenoid functional failure detection.
• No L-up solenoid functional failure detection.
• No engine torque reduction at stall.
• Regard as D position. (DTC P0707)
• There is a priority in order of D, 3, 2, L, R, N, and P.
(DTC P0708)
• Check Trans “ON”.
• DTC stored.
• MIL request “ON”. (EURO 4 only)
Conditions For Clearing The DTC
•
The DTC can be cleared from the TCM history by
using a scan tool.
• The DTC will be cleared from history when the vehicle has achieved 40 warm-up cycles without a
failure reported.
•
After more than 1 second has elapsed after the
ignition key has been turned “ON”, short between
No.11 and No.4 (ground) of DLC (Data Link
Connector). Then, after 1 second, but within 6
seconds, discontinue shorting.
Diagnostic Aids
• Inspect the wiring for poor electrical connection at the
TCM. Look for possible bent, backed out, deformed
or damaged terminals. Check for weak terminal
tension as well. Also check for a chafed wire that
could short to bare metal or other wiring.
Inspect for a broken wire inside the insulation.
• W hen diagnosing for a possible intermittent short o
r
open condition, move the wiring harness while
observing test equipment for a change.
• Check neutral start switch for proper mounting and adjustment. (Refer to section 7A4 Components (1)
neutral start switch)
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ISUZU KB P190 2007

7A2-56 TRANSMISSION CONTROL SYSTEM (AW30–40LE)
(2) Select position switches is not detecting failure o
r
not deciding failure.
(3) Output revolution sensor is not detecting failure o
r
not deciding failure.
(4) Output revolution is more than 600rpm.
(5) If output signal pulse count is more than 9 ×500,
any pulse is not detected from input revolution
sensor.
(6)
Any pulse is not detected at 2nd from input
revolution sensor after condition (9) is met.
(7) Shift solenoid S1 and Shift solenoid S2 are not detecting electric failure or not deciding electric
failure.
(8) Shift solenoid S1 and Shift solenoid S2 are not deciding functional failure.
If the following conditions are not met, keep the
failure detection counter.
(9) 3.5 seconds or more passed after the gear change signal output.
(10) Not 4th gear.
Action Taken When The DTC Sets
• No L-up.
• No line pressure reduction control at gear shift.
• No torque reduction control.
• No slope control
• No output revolution sensor failure detection.
• Cancel input revolution condition of the “Condition For Running The DTC” of system voltage erro
r
detection.
• No shift solenoid failure detection.
• No L-up solenoid failure detection.
• DTC stored.
• Check Trans "ON".
• MIL request "ON". (EURO 4 only)
Conditions For Clearing The DTC
• The DTC can be cleared from the TCM history by
using a scan tool.
• The DTC will be cleared from history when the vehicle has achieved 40 warm-up cycles without a
failure reported.
•
After more than 1 second has elapsed after the
ignition key has been turned “ON”, short between
No.11 and No.4 (ground) of DLC (Data Link
Connector). Then, after 1 second, but within 6
seconds, discontinue shorting.
Diagnostic Aids
• Inspect the wiring for poor electrical connection at the TCM. Look for possible bent, backed out, deformed
or damaged terminals. Check for weak terminal
tension as well. Also check for a chafed wire that
could short to bare metal or other wiring.
Inspect for a broken wire inside the insulation.
• W hen diagnosing for a possible intermittent short o
r
open condition, move the wiring harness while
observing test equipment for a change.
• Check input speed sensor for proper mounting and adjustment.
Circuit/System Testing DTC P0717
Step Action Value(s) YES NO
1
W as the On-Board Diagnostic (OBD) System check
performed? — Go to
Step 2 Go to OBD
system check
2 1. Install a scan tool.
2. Turn on the ignition.
3. Review and record scan tool data.
4. Operate the vehicle within scan tool data.
Does a scan tool indicate DTC P0717? — Go to
Step 3 Refer to
Diagnostic Aids
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ISUZU KB P190 2007

7A2-60 TRANSMISSION CONTROL SYSTEM (AW30–40LE)
(2) Select position switches is not detecting failure o
r
not deciding failure.
(3) Input revolution sensor is not detecting failure o
r
not deciding failure.
(4) Output revolution calculated by input revolution is more than 300rpm.
(5) If input revolution signal pulse count is more than 13 ×500, any pulse is not detected from output
revolution sensor.
Action Taken When The DTC Sets
• The TCM uses input speed sensor as a vehicle
speed.
• No squat control.
• No torque reduction control.
• No line pressure control.
• No use 4th gear.
• No lock-up control.
• No reverse lock out control.
• No slope control.
• Control gear change by calculating vehicle speed from input revolution sensor.
• No coast control.
• No input revolution sensor failure detection.
• Keep oil temperature sensor open failure detection accumulated timer.
• No select position switch (OPEN) failure decision.
• No T/F Hi-Low SW failure detection.
• No shift solenoid functional failure detection.
• No L-up solenoid functional failure detection.
• No lockup “OFF” control at fuel cut.
• Check Trans “ON”.
• DTC stored.
• MIL request “ON”. (EURO 4 only)
Conditions For Clearing The DTC
• The DTC can be cleared from the TCM history by
using a scan tool.
• The DTC will be cleared from history when the vehicle has achieved 40 warm-up cycles without a
failure reported.
•
After more than 1 second has elapsed after the
ignition key has been turned “ON”, short between
No.11 and No.4 (ground) of DLC (Data Link
Connector). Then, after 1 second, but within 6
seconds, discontinue shorting.
Diagnostic Aids
• Inspect the wiring for poor electrical connection at the
TCM. Look for possible bent, backed out, deformed
or damaged terminals. Check for weak terminal
tension as well. Also check for a chafed wire that
could short to bare metal or other wiring.
Inspect for a broken wire inside the insulation.
• W hen diagnosing for a possible intermittent short o
r
open condition, move the wiring harness while
observing test equipment for a change.
• Check output revolution sensor for proper mounting and adjustment.
Circuit/System Testing DTC P0722
Step Action Value(s) YES NO
1
W as the On-Board Diagnostic (OBD) System check
performed ? — Go to
Step 2 Go to OBD
system check
2 1. Install a scan tool.
2. Turn on the ignition.
3. Review and record scan tool data.
4. Operate the vehicle within scan tool data.
Does a scan tool indicate DTC P0722? — Go to
Step 3 Refer to
Diagnostic Aids
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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-113
(2) All of the following conditions are met.
• Device Control is not operating.
• Disable Normal Communication is receiving
enable.
• DTC Clear is not operating.
The following condition at ignition “OFF” form “ON” is
detected seven times in total in 1 cycle.
• Receiving BUS “OFF” information from CAN
controller.
Action Taken When The DTC Set
• Throttle judgment on torque reduction control, line
pressure control at stationary status, line pressure
reduction control at gear change and line pressure
reduction control at garage. (Throttle opening 100%)
• Line pressure FULL output.
• Throttle judgment on gear change control. (Throttle
opening 0%)
• No line pressure reduction control at gear change.
• No torque reduction control.
• No squat control.
• No slope control.
• No L-up control.
• Control Engine rpm at 7000rpm. (No inertia
calculation)
• Control actual torque at MAX.
• Control driver torque at MAX.
• Control engine coolant temperature at 80 °C (176 °F).
• No coast control.
• No 3rd Start mode control.
• No line pressure reduction control at garage.
• No output revolution sensor failure detection.
• No input revolution sensor failure detection.
• No selector position switch failure detection.
• No oil temperature sensor failure detection.
• No T/F Hi-Low SW failure detection.
• No speed mater signal failure detection.
• No throttle signal failure detection.
• No Engine torque signal failure detection.
• No engine coolant temperature signal failure
detection.
• No Engine revolution signal failure detection.
• No shift solenoid functional failure detection.
• No L-up solenoid functional failure detection.
• No DTC U2105 failure detection.
• Cancel engine rpm condition of prerequisite of suppl
y
voltage failure detection.
• Control vehicle speed of speed meter at 0km/h.
• No torque reduction at stall.
• No cruise control.
• No warm up control.
• DTC stored.
• Check Trans “ON”.
• MIL request “ON”. (EURO 4 only)
Conditions For Clearing The DTC
• The DTC can be cleared from the TCM history by
using a scan tool.
• The DTC will be cleared from history when the vehicle has achieved 40 warm-up cycles without a
failure reported.
•
After more than 1 second has elapsed after the
ignition key has been turned “ON”, short between
No.11 and No.4 (ground) of DLC (Data Link
Connector). Then, after 1 second, but within 6
seconds, discontinue shorting.
Diagnostic Aids
• Inspect the wiring for poor electrical connection at the
TCM. Look for possible bent, backed out, deformed
or damaged terminals. Check for weak terminal
tension as well. Also check for a chafed wire that
could short to bare metal or other wiring. Inspect for a
broken wire inside the insulation.
• W hen diagnosing for a possible intermittent short o
r
open condition, move the wiring harness while
observing test equipment for a change.
• Inspect the wiring for EMI (Electro-Magnetic
Interference). Check that all wires are properly routed
away from coil, and generator. Also check fo
r
improperly installed electrical options. W hen this test
is performed, turn “OFF” on electronic auto parts
switches to improperly for a noise preventing.
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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-117
(3) All of the following conditions are met.
• Device Control is not operating.
• Disable Normal Communication is receiving
enable.
• DTC Clear is not operating.
(4) DTC U2104 is not detecting failure or not deciding failure.
Condition For Setting The DTC
Detection standard is met for 2.5 second continuously.
Detection standard:
If one or more ID sent from Engine Control Module
(ECM) is not completed receiving for 2 basic cycles
since last receiving completion.
Action Taken When The DTC Sets
• Throttle judgment on torque reduction control, line
pressure control at stationary status, line pressure
reduction control at gear change and line pressure
reduction control at garage. (Throttle opening 100%)
• Line pressure FULL output.
• Throttle judgment on gear change control (Throttle
opening 0%).
• No line pressure reduction control at gear change.
• No torque reduction control.
• No squat control.
• No slope control (keep mode).
• No L-up control.
• Control Engine rpm at 7000rpm (No inertia
calculation).
• Control actual torque at MAX.
• Control driver torque at MAX.
• Control engine coolant temperature at 80 °C (176 °F).
• No coast control.
• No 3rd Start mode control.
• No line pressure reduction control at garage.
• No output revolution sensor failure detection.
• No C-0 rev sensor failure detection.
• No selector position switch failure detection.
• No oil temperature sensor failure detection.
• No T/F Hi-Low SW failure detection (Execute T/F
judgment using only T/F-SW ).
• No speed mater signal failure detection.
• No throttle signal failure detection.
• No Engine torque signal failure detection.
• No engine coolant temperature signal failure
detection.
• No Engine revolution signal failure detection.
• No shift solenoid functional failure detection.
• No L-up solenoid functional failure detection.
• Cancel engine rpm condition of prerequisite of suppl
y
voltage failure detection.
• Control vehicle speed of speed meter at 0km/h.
• No torque reduction at stall.
• No cruise control.
• No warm up control.
• Check Trans “ON”.
• DTC stored.
• MIL request “ON”. (EURO 4 only)
Conditions For Clearing The DTC
• The DTC can be cleared from the TCM history by
using a scan tool.
• The DTC will be cleared from history when the vehicle has achieved 40 warm-up cycles without a
failure reported.
• After more than 1 second has elapsed after the ignition key has been turned “ON”, short between
No.11 and No.4 (ground) of DLC (Data Link
Connector). Then, after 1 second, but within 6
seconds, discontinue shorting.
Diagnostic Aids
• Inspect the wiring for poor electrical connection at the
TCM. Look for possible bent, backed out, deformed
or damaged terminals. Check for weak terminal
tension as well. Also check for a chafed wire that
could short to bare metal or other wiring. Inspect for a
broken wire inside the insulation.
• W hen diagnosing for a possible intermittent short o
r
open condition, move the wiring harness while
observing test equipment for a change.
• Inspect the wiring for EMI (Electro-Magnetic
Interference). Check that all wires are properly routed
away from coil, and generator. Also check fo
r
improperly installed electrical options. W hen this test
is performed, turn “OFF” on electronic auto parts
switches to improperly for a noise preventing.
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CONSTRUCTION AND FUNCTION 7A1-15
Line Pressure Solenoid • The line pressure solenoid is turned ON or OFF according to the signal from the TCM. It switches the
line pressure between high and low pressure.
• While no power is supplied, the solenoid supplies high pressure.
Shift Solenoid • The shift solenoid is of the duty cycle type, which is turned ON or OFF at 50Hz. The ratio of the ON and
OFF time can be freely controlled in the position of 0 - 100%.
• While no power is supplied, the solenoid supplies output pressure.
• The low clutch solenoid adjusts the low clutch pressure, the high clutch solenoid adjusts the high clutch
pressure, the 2-4 brake solenoid adjusts the 2-4 brake pressure, and the low & reverse brake solenoid
adjusts the low & reverse brake pressure respectively.
Lock-up Solenoid • The lock-up solenoid is of the duty cycle type which is turned ON or OFF at 50Hz. The ratio of the ON
and OFF time can be freely controlled in the position of 0 - 100%.
• While no power is supplied, the solenoid drains the output pressure.
Figure 23. Shift Solenoid Figure 24. Lock-up Solenoid
Figure 25. Location of Solenoid
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