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
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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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
ON-VEHICLE SERVICE (AW30–40LE) 7A3-49
Major Components
Disassembly, inspection and reassembly of each
component group is indicated in the following chapter.
Before reassembly, make sure, again, that all
component groups are assembled correctly.
If something wrong is found in a certain component
group during assembly, inspect and repair this group
immediately.
General Assembly Notes:
1. The automatic transmission is composed of highly
precision-finished parts, necessitating careful
inspection before assembly because even a small
nick could cause fluid leakage or affect
performance.
2. Before assembling new clutch discs and brake
bands, soak them in automatic transmission fluid fo
r
at least thirty minutes.
3. Apply automatic transmission fluid on the sliding o
r
rotating surfaces of parts before assembly.
4. Use petroleum jelly to keep small parts in thei
r
palces.
5. Do not use adhesive cements on gaskets and similar parts.
6. W hen assembling the transmission, be sure to use new gaskets and O-rings.
7. Dry all parts with compressed air - never use shop rags.
8. Be sure to install the thrust bearings and races in the correct direction and position.
Bearing and Race
RUW 36AMF000201
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ISUZU KB P190 2007
7A4–36 UNIT REPAIR (AW30–40LE)
Diaassembly, Inspection and
Reassembly of minor Components
NOTE: The instructions here are organized so that you
work on only one component group at a time.
This will help avoid confusion from similar-looking parts
of different subassemblies being on your workbench at
the same time.
The component groups are inspected and repaired from
the converter housing side.
As much as possible, complete the inspection, repair
and reassembly before proceeding to the next
component group. If a component group cannot be
reassembled because parts are being ordered, be sure
to keep all parts of that group in separate container
while proceeding with disassembly, inspection, repair
and reassembly of other component groups.
Recommended ATF type DEXRON III.
General Cleaning Notes:
1. All disassembled parts should be washed clean and any fluid passages and holes should be blown
through with compressed air.
2. When using compressed air to dry parts, always aim away from yourself to prevent accidentally spraying
automatic transmission fluid in your face.
3. The recommended automatic transmission fluid should be used for cleaning.
Parts Arrangement:
1. After cleaning, the parts should be arranged inproper order to allow performing inspection, repairs,
and reassembly with efficiency.
2. When disassembling a valve body, be sure to keep each valve together with the corresponding spring.
3. New brakes and clutches that are to be used for replacement must be soaked in transmission fluid
for at least thirty minutes before assembly.
General Assembly:
1. All oil seal rings, clutch discs, clutch plates, rotating parts, and sliding surfaces should be coated with
transmission fluid prior to reassembly.
2. All gaskets and rubber O-ring should be replaced.
3. Make sure that the ends of a snap ring are not aligned with one of the cutouts and are installed in
the groove correctly.
4. If a worn bushing is to be replaced, the subassembly containing that bushing must be
replaced.
5. Check thrust bearings and races for wear or damage. Replace if necessary.
6. Use petroleum jelly or vaseline to keep parts in place.
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ISUZU KB P190 2007