2007 ISUZU KB P190 Circuit

7A2-86 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

DTC P0757 (Flash Code 52)






RTW 77ALF001501

Circuit Description
The shift solenoid S2 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 550 rpm.
(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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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

7A2-90 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

DTC P0962 or P0963 (Flash Code 35)




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 TCM-controled
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 continuously.
• 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.
Condition For Setting The DTC
(1) All of the following conditions are met for 12.5
seconds or more continuously. (DTC P0962)
• 1 second or more passed after ignition short
failure detection condition is met or ignition short
failure is never detected after ignition “ON”.

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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

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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-93

DTC P0973 or P0974 (Flash Code 31)




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 shift 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.
(2) Not emergency mode.
(3) 0.025 seconds or more passed after the state o
f
power “ON” solenoid is changed.
(4) All of the following conditions are met. • Device Control is not operating.
• Disable Normal Communication is receiving
enable.
• DTC Clear is not operating.


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ISUZU KB P190 2007

7A2-94 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 P0973)
• Voltage at connector pin is ignition voltage when
solenoid is “OFF”. (DTC P0974)
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.
• 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 P0973 or P0974

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 P0973 or P0974? — 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 C94-16 and terminal C94-1 (GND) 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 10

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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-97

DTC P0976 or P0977 (Flash Code 32)




RTW 77ALF001501

Circuit Description
The shift solenoid S2 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 shift 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.
(2) Not emergency mode.
(3) 0.025 seconds or more passed after the state o
f
power “ON” solenoid is changed.
(4) All of the following conditions are met. • Device Control is not operating.
• Disable Normal Communication is receiving
enable.
• DTC Clear is not operating.



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ISUZU KB P190 2007

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