2007 ISUZU KB P190 automatic transmission

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

7A2-72 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

7A2-76 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

Circuit/System Testing DTC P0751
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 P0751? — 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 commanded gear and current gear on a
scan tool.
1. Turn “ON” the ignition with engine “ON”.
2. Road testing the vehicle.
3. The throttle position is more than 8%.
4. The vehicle speed is more than 5 km/h (3 mph).

Did the TCM detect 4th gear ratio in case of 1st gear
target, and 3rd gear ratio in case of 2nd gear target?
Above conditions were indicated on a scan tool
display? — Refer to
Diagnostic Aids Go to
Step 5
5 Check the following items.
• Check the shift solenoid valve S1. (Refer to
Section 7A3)
• Shift solenoid valve S1 stuck “OFF” the release
position (Refer to Section 7A4)
• Misaligned or damaged valve body gasket.
• Restricted apply passage.
If the problem found, replaces 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 valve body. (Refer to Section 7A4).

Is the action complete? — Go to
Step 8 —

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ISUZU KB P190 2007

7A2-80 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

Circuit/System Testing DTC P0752
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 P0752? — 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 commanded gear and current gear on
the scan tool.
1. Turn “ON” the ignition with engine “ON”.
2. Road testing the vehicle.
3. The throttle position is more than 8%.
4. The vehicle speed is more than 5 km/h (3 mph).

Did the TCM detect 2nd gear ratio in case of 3rd gear
target? Above conditions were indicated on the scan
tool display? — Refer to
Diagnostic Aids Go to
Step 5
5 Check the following items.
• Check the shift solenoid valve S1. (Refer to
Section 7A3)
• Shift solenoid valve S1 stuck “ON” the release
position (Refer to Section 7A4)
• Misaligned or damaged valve body gasket.
• Restricted apply passage.
If the problem found, replaces 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 valve body. (Refer to Section 7A4).

Is the action complete? — Go to
Step 8 —

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ISUZU KB P190 2007

7A2-84 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

Circuit/System Testing DTC P0756
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 the 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 P0756? — 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 commanded gear and current gear on
the scan tool.
1. Turn “ON” the ignition with engine “ON”.
2. Road testing the vehicle.
3. The throttle position is more than 8%.
4. The vehicle speed is more than 5 km/h (3 mph).

Did the TCM detect 1st gear ratio in case of 2nd gear
target, and 4th gear ratio in case of 3rd gear target?
Above conditions were indicated on a scan tool
display? — Refer to
Diagnostic Aids Go to
Step 5
5 Check the following items.
• Check the shift solenoid valve S2. (Refer to
Section 7A3)
• Shift solenoid valve S2 stuck “OFF” the release
position (Refer to Section 7A4)
• Misaligned or damaged valve body gasket.
• Restricted apply passage.
If the problem found, replaces 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 valve body. (Refer to Section 7A4).

Is the action complete? — Go to
Step 8 —

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TO MODEL INDEX
ISUZU KB P190 2007

7A2-88 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

Circuit/System Testing DTC P0757
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 P0757? — 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 commanded gear and current gear on
the scan tool.
1. Turn “ON” the ignition with engine “ON”.
2. Road testing the vehicle.
3. The throttle position is more than 8%.
4. The vehicle speed is more than 5 km/h (3 mph).

Did the TCM detect 2nd gear ratio in case of 1st gear
target, and 3rd gear ratio in case of 4th gear target?
Above conditions were indicated on the scan tool
display? — Refer to
Diagnostic Aids Go to
Step 5
5 Check the following items.
• Check the shift solenoid valve S2. (Refer to
Section 7A3)
• Shift solenoid valve S2 stuck “ON” the release
position (Refer to Section 7A4)
• Misaligned or damaged valve body gasket.
• Restricted apply passage.
If the problem found, replaces 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 valve body. (Refer to Section 7A4).

Is the action complete? — Go to
Step 8 —

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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-91

• Feedback current value is less than 92 mA
(2)
All of the following conditions are met for 0.5
seconds or more continuously. (DTC P0963)
• 1 second or more passed after open failure
detection condition is met or open failure is not
detected after ignition “ON”.
• Feedback current value is more than 1357 mA.
Action Taken When The DTC Sets
• No squat control.
• No line pressure reduction control at gear change.
• No lock-up 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.
• No pressure control solenoid Feedback stuck failure detection.
• 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 P0962 or P0963

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 scan tool data.
4. Operate the vehicle within scan tool data.

Does a scan tool indicate DTC P0962 or P0963? — Go to
Step 3 Refer to
Diagnostic Aids
3 Measure the resistance of pressure control solenoid.
1. Turn “OFF” the ignition.
2. Disconnect the automatic transmission connector.
3. Measure the resistance between automatic
transmission terminal E54-2 and automatic
transmission terminal E54-6.

Is the resistance specified value? 5 to 5.6Ω at
20 °C (68 °F) Go to
Step 4 Go to Step 7

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007