2007 ISUZU KB P190 Engine wiring

7A2-98 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

Condition For Setting The DTC
The TCM detects following conditions for 0.5 seconds
continuously at shifting.
• Voltage at connector pin is 0V when solenoid is “ON”.
(DTC P0976)
• Voltage at connector pin is ignition voltage when
solenoid is “OFF”. (DTC P0977)
Action Taken When The DTC Sets
• No L-up control.
• No line pressure reduction control at gear change.
• No torque reduction control.
• No squat control.
• No slope control (keep mode).
• No line pressure reduction control at garage.
• No input revolution sensor failure detection.
• No shift solenoid failure detection.
• No L-up solenoid failure detection.
• Change to emergency mode.
• 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.

Circuit/System Testing DTC P0976 or P0977

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. Start the engine.
3. Depress the brake pedal and place the select lever in D position.
4. Press the 3rd start switch. (Turn the 3rd start switch “ON”.)
5. Press the 3rd start switch again. (Turn the 3rd start switch “OFF”.)

Does a scan tool indicate DTC P0976 or P0977? — Go to
Step 3 Refer to
Diagnostic Aids
3 1. Turn “ON” the ignition with the engine “ON”.
2. Place the selector lever in the “P” position.
3. Measure the voltage between terminal C94-15 and terminal C94-1 on the TCM pigtail connector by 5-
8840-0285-0 DMM.

Is the voltage specified value? 8∼16V Go to
Step 4 Go to Step 5

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ISUZU KB P190 2007

7A2-106 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

(4) All of the following conditions are met.
• Device Control is not operating.
• Disable Normal Communication is receiving enable.
• DTC Clear is not operating.
Condition For Setting The DTC
The TCM detects following conditions for 0.5 seconds
continuously at shifting.
• Voltage at connector pin is 0V when solenoid is “ON”.
(DTC P2769)
• Voltage at connector pin is ignition voltage when
solenoid is “OFF”. (DTC P2770)
Action Taken When The DTC Sets
• No L-up solenoid functional failure detection.
• No squat control. (DTC P2770)
• The TCM fixes to 1st gear when the vehicle speed is less than 10 km/h (6 mph).
• 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.5 (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.
Circuit/System Testing DTC P2769 or P2770

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. Start the engine.
3. Drive the vehicle in D position.
4. Accelerate the vehicle until the gear position
becomes the 4th.
5. Release the accelerator pedal and accelerate the vehicle until the gear position becomes the 4th
again.

Does a scan tool indicate DTC P2769 or P2770? — Go to
Step 3 Refer to
Diagnostic Aids

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ISUZU KB P190 2007

7A2-110 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

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.

Circuit/System Testing DTC P2773 or P2774
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 P2773 or P2774? — Go to
Step 3 Refer to
Diagnostic Aids
3 Observe the 4L signal data of the TCM on the scan tool.
1. Turn “ON” the ignition with engine “ON”.
2. Perform the road testing.
3. Check the 4L signal data on a scan tool.

W as the problem found? — Go to
Step 4 Refer to
Diagnostic Aids
4 Observe the 4L signal data of the TCM on a scan tool.
1. Turn “ON” the ignition with engine “ON”.
2. Perform the road testing.
3. Check the 4L signal data on a scan tool.

Is the 4L signal fixed “ON”? (DTC P2773) — Go to
Step 6 Go to Step 5
5 Observe the 4L signal data of the TCM on a scan tool.
1. Turn “ON” the ignition with engine “ON”.
2. Perform the road testing.
3. Check the 4L signal data on a scan tool.

Is the 4L signal fixed “OFF”? (DTC P2774) — Go to
Step 6 Go to Step 8
6 Replace or Repair the wire between the TCM terminal
C94-21 and the T/F control unit terminal C111-7.

Is the action complete? — Go to
Step 9 —

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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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TO MODEL INDEX
ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-93
Intermittent Conditions
ChecksAction
Definition:
The problem is not currently present but is indicated in DTC History.
OR
There is a customer complaint, but the symptom cannot currently be duplicated, if the problem is not DTC related.
Preliminary Checks • Refer to Symptoms - Transmission Controls before starting.
Harness/ Connector Many intermittent open or shorted circuits are affected by harness/ connector
movement that is caused by vibration, engine torque, bumps/ rough pavement, etc.
Test for this type of condition by performing the applicable procedure from the
following list:
• Move related connectors and wiring while monitoring the appropriate scan tool data.
• Move related connectors and wiring with the component commanded ON, and OFF, with the scan tool. Observe the component operation.
• With the engine running, move related connectors and wiring while monitoring engine operation.
If harness or connector movement affects the data displayed, component/ system
operation, or engine operation, inspect and repair the harness/ connections as
necessary.
Electrical Connections or Wiring Poor electrical connections, terminal tension or wiring problems cause most intermittent. To perform the following inspections:
• Poor mating of the connector halves, or terminals improperly seated in the connector body.
• Improperly formed or damaged terminals. Test for poor terminal tension.
• Poor terminal to wire connections including terminals crimped over insulation. This requires removing the terminal from the connector body.
• Corrosion/ water intrusion. Pierced or damaged insulation can allow moisture to enter the wiring. The conductor can corrode inside the insulation, with little
visible evidence. Look for swollen and stiff sections of wire in the suspect
circuits.
• Wires that are broken inside the insulation.
• Harness for pinched, cut or rubbed through wiring.
• Ensure that the wiring does not come in contact with hot exhaust components.
Control Module Power and Grounds
Component Power and Grounds Poor power or ground connections can cause widely varying symptoms.
• Test all control module power supply circuits. Many vehicles have multiple circuits supplying power to the control module. Other components in the system
may have separate power supply circuits that may also need to be tested.
Inspect connections at the module/ component connectors, fuses, and any
intermediate connections between the power source and the module/
component. A test lamp or a DMM may indicate that voltage is present, but
neither tests the ability of the circuit to carry sufficient current. Ensure that the
circuit can carry the current necessary to operate the component.
• Test all control module ground and system ground circuits. The control module may have multiple ground circuits. Other components in the system may have
separate grounds that may also need to be tested. Inspect grounds for clean
and tight connections at the grounding point. Inspect the connections at the
component and in splice packs, where applicable. Ensure that the circuit can
carry the current necessary to operate the component.

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ISUZU KB P190 2007

TRANSFER CONTROL SYSTEM 7D1-61
From 4H to 4L; Even after the correction step 3-3(*), 4Lo indicator blinks at 4Hz
Step Action Yes No
1 Is the ignition switch ON? Turn it OFF once.
Go to step 2.
2 Turn ON the ignition switch and
check the valve. Do not start
the engine.
Has the valve check for 2
seconds been completed
normally? Go to step 3.
Refer to the paragraph about the
indicator when it does not react
when shifted from 2H to 4H.
After taking the remedy, trace this
chart from the beginning.
3 Shift to 2H.
Can be shifted to 2H and then to
4H? Go to step 4.
Refer to the paragraph about
shifting from 2H to 4H.
In particular, check if not at the
Check4W D condition, return to
this chart and trace it from the
beginning.
4 Set to N position in case of AT
and set to the neutral position in
case of MT and check if the
lamp blinks at 4Hz after
operation.
Failed T/M position switch and
harness (failure of TM1 and TM2
harness and their related
switches shown in the figure).
Incorrect wiring.
Repair as required and trace this
chart from the beginning. Shift back to 4H and go to step 5.
5
Start the engine and use the
vehicle.
Does the speedometer run at
this time? Go to step 6.
Failure of speed sensor or
disconnection or short of harness
(for the meter).
After repairing, trace this chart
from the beginning.
6 Check the harness between the
transfer controller and speed
sensor.
(Check the engine rotation
detection harness at the same
time.)
Is any trouble detected? Failed harness between the
transfer controller and speed
sensor.
After repairing, trace this chart
from the beginning.
(Repair the engine rotation
detection unit, if required.) Go to step 7.
7
Run the vehicle for several
meters, stop it, meet the
permission requirements for
operation limits.
Did you wait for several seconds
after the requirements were
met? Failed controller.
Replace the controller and trace
this chart from the beginning. You did not wait for enough time.
Optimum waiting time is 1 second
or maximum 3 minutes,
depending on the previous
conditions.
Refer to the paragraph about
operation without failure.
*Before determining a trouble (Non-trouble mode)


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ISUZU KB P190 2007

7D1-62 TRANSFER CONTROL SYSTEM
From 4L to 4H: After the correction step 4-3(*), 4Lo indicator blinks at 4H.
Step Action Yes No
1 Is the ignition switch ON? Turn it OFF once.
Go to step 2.
2 Turn ON the ignition switch and
check the valve. Do not start
the engine.
Has the valve check for 2
seconds been completed
normally? Go to step 3.
Refer to the paragraph about the
indicator when it does not react
when shifted from 2H to 4H.
After taking the remedy, trace this
chart from the beginning.
3 Can be shifted to 2H and then to
4L? Go to step 4.
(Impossible usually.)
Failed controller In case of Check 4W D, shifting to
2H is possible.
Returning to 4L is impossible.
Refer to the paragraph about
Check4W D.
4 Set to N position in case of AT
and set to the neutral position in
case of MT and check if the
lamp blinks at 4Hz after
operation.
Failed T/M position switch and
harness (failure of TM1 and TM2
harness and their related
switches shown in the figure).
Incorrect wiring.
Repair as required and trace this
chart from the beginning. Press the operation switch of 4L
and go to step 5.
5 Start the engine and use the
vehicle.
Does the speedometer run at
this time? Go to step 6.
Failure of speed sensor or
disconnection or short of harness
(for the meter).
After repairing, trace this chart
from the beginning.
6 Check the harness between the
transfer controller and speed
sensor.
(Check the engine rotation
detection harness at the same
time.)
Is any trouble detected? Failed harness between the
transfer controller and speed
sensor.
After repairing, trace this chart
from the beginning.
(Repair the engine rotation
detection unit, if required.) Go to step 7.
7
Run the vehicle for several
meters, stop it, meet the
permission requirements for
operation limits.
Did you wait for several seconds
after the requirements were
met? Failed transfer controller.
Replace the controller and trace
this chart from the beginning. You did not wait for enough time.
Optimum waiting time is 1 second
or maximum 3 minutes,
depending on the previous
conditions.
Refer to the paragraph about
operation without failure.
*Before determining a trouble (Non-trouble mode)



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ISUZU KB P190 2007