ISUZU KB P190 2007 Workshop Repair Manual

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-65

Circuit/System Testing DTC P0741
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 P0741? — Go to
Step 3 Refer to
Diagnostic Aids
3 Perform the transmission fluid checking procedure.
Refer to checking Transmission Fluid level and
Condition in Automatic Transmission 7A section.
If the problem found, repair or replace necessary.

W as the problem found? — Go to
Step 8 Go to Step 4
4 Observe the TCC slip speed data on a scan tool.
1. Turn “ON” the ignition with the engine “ON”.
2. Road testing the vehicle.
3. The throttle position is more than 20%.
4. The vehicle speed is more than 5 km/h (3 mph).
5. The TCC slip speed is less than 100 rpm at 4th gear L-up.

Above conditions were indicated on a scan tool
display? — Refer to
Diagnostic Aids Go to
Step 5
5 Check the following items.
• Check the L-up solenoid valve. (Refer to Section
7A3)
• L-up solenoid valve stuck “OFF” the release
position (Refer to Section 7A4)
• Misaligned or damaged valve body gasket.
• Restricted apply passage.

If the problem found, replaces as necessary.
W as the problem found? — Go to
Step 8 Go to Step 6
6 Check the DTC on a scan tool.

Is DTC found on a scan tool? — Go to
Step 7 Go to Step 8
7 Replace the Torque converter (Refer to Section 7A4).

Is the action complete? — Go to
Step 8 —

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ISUZU KB P190 2007

7A2-66 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

Step Action Value(s) YES NO
8 1. Reconnect all previously disconnected harness
connector(s).
2. Clear the DTCs with a scan tool.
3. Turn “OFF” the ignition.
4. Start the engine.
5. Operate the vehicle within the Conditions For Running the DTC. You may also operate the
vehicle within the conditions that you observed
from the Freeze Frame/ Failure Records.

Did the DTC fail this ignition? — Go to
Step 2 Go to Step 9
9 Observe the stored information, Capture Info with a
scan tool.

Are there any DTCs that you have not diagnosed? — Go
to
Diagnostic
Trouble Code (DTC) List Verify repair

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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-67

DTC P0742 (Flash Code 53)






RTW 77ALF001501

Circuit Description
The lock-up solenoid SL of the torque converter clutch
(TCC) controls the lock-up clutch by a signal according
to the lock-up position judgment of the Transmission
Control Module (TCM) when the vehicle runs.
This function can improve the fuel consumption to
almost the same extent as the manual transmission.
The lock-up solenoid SL is put into B+ by the TCM, so
that the solenoid is actuated with the result of lock-up.
Condition For Running The DTC
All of the following conditions are met.
(1)
All of the following conditions are met for 2
seconds or more continuously.
• The supply voltage is more than 10.2 volts and less than 15.5 volts.
• DTC U2104 is not detecting failure or not deciding failure.
• DTC U2105 is not detecting failure or not deciding failure.
• Engine revolution signal is not detecting failure or not deciding failure.
• The engine revolution is more than 550rpm.

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ISUZU KB P190 2007

7A2-68 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

(2) Oil temperature is more than 20 °C (68 °F), and
water temperature signal is more than 70 °C
(158 °F).
(3) 20 seconds or more passed after D position is detected.
(4) Oil temperature sensor is not deciding failure.
(5) Engine coolant temperature sensor is not detecting failure or not deciding failure.
(6) The engine revolution is more than 600 rpm.
(7) Engine revolution sensor is not detecting failure o
r
not deciding failure.
(8) T/F condition is high.
(9) T/F Hi-Low SW is not detecting failure or not deciding failure.
(10) Output revolution sensor is not detecting failure o
r
not deciding failure.
(11) S1 solenoid is not detecting failure or not deciding
failure. (Electronic failure)
(12) S2 solenoid is not detecting failure or not deciding
failure. (Electronic failure)
(13) L-up solenoid is not detecting failure or not
deciding failure. (Electronic failure)
(14) Selector position switch is not detecting failure o
r
not deciding failure.
(15) DTC U2104 is not detecting failure or not deciding
failure.
(16) DTC U2105 is not detecting failure or not deciding
failure.
(17) Input revolution sensor is not deciding failure.
(18) Throttle signal is not detecting failure or not
deciding failure.
(19) Not emergency mode.
(20) Engine torque signal is not detecting failure or not
deciding failure.
(21) Pressure control solenoid is not detecting failure
not deciding failure.
(22) 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
The following conditions are detected two times or more
between ignition “ON” and ignition “OFF”.
The TCM detects following conditions are met for 1
second continuously.
• 2 second passed after gear change output and L-up “ON”/”OFF” output.
• T/C revolution difference more than 100 rpm for 1 second continuously.
• 3rd gear lock-up “OFF”.
Action Taken When The DTC Sets
• No squat control. (For preventing engine stall)
• Fix 1st gear to prevent engine stall when vehicle speed is and below 10 km/h (6 mph). (Cancel at 15
km/h {9 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.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.

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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-69

Circuit/System Testing DTC P0742
Step Action Value(s) YES NO
1
W as the On-Board Diagnostic (OBD) System Check
performed? 1. Install the scan tool. — 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 P0742? — Go to
Step 3 Refer to
Diagnostic Aids
3 Perform the transmission fluid checking procedure.
Refer to checking Transmission Fluid level and
Condition in Automatic Transmission 7A section.
If the problem found, repair or replaces necessary.

W as the problem found? — Go to
Step 8 Go to Step 4
4 Observe the TCC slip speed data on a scan tool.
1. Turn “ON” the ignition with engine “ON”.
2. Road testing the vehicle.
3. The throttle position is more than 20%.
4. The vehicle speed is between 5 km/h (3 mph) and 100 km/h (62 mph).
5. The TCC slip speed is more than 150 rpm at 2nd gear L-up “OFF”.
6. The throttle position is more than 25%.
7. The vehicle speed is between 5 km/h (3 mph) and 80 km/h (50 mph).
8. The T/C revolution difference is less than 100 rpm at 3rd L-up “OFF”.

Above conditions were indicated on a scan tool
display? — Refer to
Diagnostic Aids Go to
Step 5
5 Check the following items.
• Check the L-up solenoid valve. (Refer to Section
7A3)
• L-up solenoid valve stuck “ON” the release position
(Refer to Section 7A4)
• Misaligned or damaged valve body gasket.
• Restricted apply passage.

If the problem found, replaces as necessary.

W as the problem found? — Go to
Step 8 Go to Step 6
6 Check the DTC on a scan tool.

Is DTC found on a scan tool? — Go to
Step 7 Go to Step 8

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ISUZU KB P190 2007

7A2-70 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

Step Action Value(s) YES NO
7 Replace the Torque converter (Refer to Section 7A4).

Is the action complete? — Go to
Step 8 —
8 1. Reconnect all previously disconnected harness
connector(s).
2. Clear the DTCs with a scan tool.
3. Turn “OFF” the ignition.
4. Start the engine.
5. Operate the vehicle within the Conditions For Running the DTC. You may also operate the
vehicle within the conditions that you observed
from the Freeze Frame/ Failure Records.

Did the DTC fail this ignition? — Go to
Step 2 Go to Step 9
9 Observe the stored information, Capture Info with a
scan tool.

Are there any DTCs that you have not diagnosed? — Go
to
Diagnostic
Trouble Code (DTC) List Verify repair


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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-71

DTC P0746 (Flash Code 45)






RTW 77ALF001501

Circuit Description
The pressure control solenoid is a PW M duty control
solenoid located in the valve body.
The pressure control solenoid is a Transmission
Control Module (TCM)-controlled device used to
regulate transmission throttle pressure by energizing
current from the TCM.
Condition For Running The DTC
All of the following conditions are met.
(1)
All of the following conditions are met for 2
seconds or more.

• The supply voltage is more than 10.2 volts and
less than 15.5 volts.
(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.
(4) Pressure control solenoid is not detecting failure o
r
not deciding failure.
(5) Feedback AD value keeps less than 1000 for 0.5 seconds and also linear solenoid assured voltage
keeps 10.5 volts for 0.5 seconds.


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ISUZU KB P190 2007

7A2-72 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

Condition For Setting The DTC
All of the following conditions are met.
• Accumulation of feedback error current value is
more than 8A.
• Detect failure twice continuously.
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.
Action Taken When The DTC Sets
• No L-up control.
• No line pressure reduction control at gear change.
• No squat control.

• No slope control.
• No torque reduction control.
• No line pressure reduction control at garage.
• Line pressure FULL output.
• No shift solenoid functional failure detection.
• No L-up solenoid functional failure detection.
• Become emergency mode.
• Check Trans "ON".
• DTC stored.
• MIL request "ON". (EURO 4 only)
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
or open condition, move the wiring harness while
observing test equipment for change.

Circuit/System Testing DTC P0746
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. Record a scan tool data.
4. Operate the vehicle within scan tool data.

Does a scan tool indicate DTC P0746? —
Go to Step 3 Refer to
Diagnostic Aids
3 Perform the transmission fluid checking procedure.
Refer to checking Transmission Fluid level and
Condition in Automatic Transmission 7A section.
If the problem found, repair or replace necessary.

W as the problem found? —
Go to Step 9 Go to Step 4

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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-73

Step Action Value(s) YES NO
4 Measure the resistance of pressure control
solenoid.
1. Turn “OFF” the ignition.
2. Disconnect the automatic transmission connector and TCM connector.
3. Measure the resistance between automatic transmission terminal E54-2 and automatic
transmission terminal E54-6.

Is the resistance specified value? 5 to 5.6
Ω
at 20 °C
(68 °F)
Go to
Step 5 Go to Step 7
5 Measure the resistance of wire between terminal
C94-2 and terminal C94-4.
1. Turn “OFF” the ignition.
2. Connect the automatic transmission connector.
3. Disconnect the TCM connector.
4. Measure the resistance between terminal C94-2 and terminal C94-4.

Is the resistance specified value? 5 to 5.6
Ω
at 20 °C
(68 °F) Go to
Step 8 Go to Step 6
6 Repair or Replace the wire between terminals C94-
2, 4 and terminals E54-6, 2.

Is the action complete? —
Go to Step 9 —
7 Replace the pressure control solenoid. (valve body)

Is the action complete? —
Go to Step 9 —
8 Replace the TCM.
Important: The replacement TCM must be
programmed (Refer to SPS for procedure).

Is the action complete? —
Go to Step 9 —
9 1. Reconnect all previously disconnected harness
connector(s).
2. Clear the DTCs with a scan tool.
3. Turn “OFF” the ignition.
4. Start the engine.
5. Operate the vehicle within the Conditions For Running the DTC. You may also operate the
vehicle within the conditions that you observed
from the Freeze Frame/ Failure Records.

Did the DTC fail this ignition? —
Go to Step 2 Go to Step 10
10 Observe the stored information, Capture info with a
scan tool.

Are there any DTCs that you have not diagnosed? —
Go to
Diagnostic
Trouble Code (DTC) List Verify repair


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ISUZU KB P190 2007

7A2-74 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

DTC P0751 (Flash Code 41)






RTW 77ALF001501

Circuit Description
The shift solenoid S1 changes the hydraulic route with
the signals from the TCM according to the vehicle
speed and the throttle opening to control shifting. W hen
the solenoid S1 or S2 fails, the hydraulic circuit is
mechanically operated as a backup.
Condition For Running The DTC
All of the following conditions are met.
(1)
All of the following conditions are met for 2
seconds or more continuously.
• The supply voltage is more than 10.2 volts and less than 15.5 volts.

• DTC U2104 is not detecting failure or not
deciding failure.
• DTC U2105 is not detecting failure or not deciding failure.
• Engine revolution signal is not detecting failure or not deciding failure.
• The engine revolution is more than 550rpm.
(2) Oil temperature is more than 20 °C (68 °F), and
water temperature signal is more than 70 °C
(158 °F).
(3) 20 seconds or more passed after D position is detected.
(4) Oil temperature sensor is not deciding failure.

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TO MODEL INDEX
ISUZU KB P190 2007