2007 ISUZU KB P190 automatic transmission fluid

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–66
Action Taken When the DTC Sets
• The TCM requests the ECM to illuminate the MIL during the second consecutive trip in which the Conditions for
Setting the DTC are met.
• The TCM commands maximum line pressure.
• The TCM freezes transmission adaptive functions.
• The TCM inhibits 3-2 downshifts if the vehicle speed is greater than 40 km/h.
• At the time of the first failure, the TCM records the operating conditions when the conditions for setting the DTC are
met. The TCM stores this information as a Failure Record.
• At the time of the second failure, the ECM records the operating conditions when the conditions for setting the DTC
are met. The ECM stores this information as a Freeze Frame.
• The TCM stores DTC P0752 in TCM history during the second consecutive trip in which the conditions for setting
the DTC are met.
Conditions for Clearing the DTC
• The ECM turns off the MIL after the fourth consecutive drive trip in which the TCM does not send a MIL illumination
request.
• Tech 2 can clear the DTC.
• The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission
related diagnostic fault occurring.
• The TCM cancels the DTC default actions when the ignition is off long enough to power down the TCM.
Diagnostic Aids
• If you clear DTC P0752, and then cannot reset DTC P0752, the following conditions may exist:
• Fluid contamination,
• Blocked fluid circuits, or
• Restricted fluid circuits.
• Refer to 5.6 Shift Solenoid Valve State and Gear Ratio.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 This step tests the TCM commanded all shifts, all shift solenoid valves responded correctly, and if all the shifts did not occur.
3 Checks the mechanical components that cause the DTC and their state.
DTC P0752 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.7 Diagnostic
System Check

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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–68
4.22 DTC P0756 – 2-3 Shift Solenoid Valve
Performance – No First or Second Gear
DTC Description
This diagnostic procedure supports DTC P0756 2-3 Shift Solenoid (SS) Valve Performance – No First or Second Gear.
Circuit Description
The 2-3 shift solenoid (SS) valve controls the fluid flow acting on the 2-3 shift valves. The 2-3 SS valve is a normally-
open exhaust valve that is used with the 1-2 SS valve, to allow four different shifting combinations.
When the transmission control module (TCM) detects a 4-3-3-4 shift pattern, then DTC P0756 sets. DTC P0756 is a
type A DTC.
Refer to 2 W iring Diagrams and Connector Chart to aid in diagnosis.
Conditions for Running the DTC
• No DTCs P0120, P0722, P0723, P0742, P0973, P0974, P0976, P0977 or P1815.
• The engine torque is 108 – 882 Nm.
• The engine run time is greater than 5 seconds.
• The transmission fluid temperature is 20 – 130°C.
• The throttle position is greater than 10 percent.
• The output shaft speed is greater than 150 r.p.m.
Conditions for Setting the DTC
Both of the following conditions must occur twice during the same trip:
• Fail Case 1: The TCM commands 1st gear when the output shaft speed is 200 r.p.m. or greater, the engine torque
is 40 – 350 Nm, and the resulting gear ratio is 0.73:1 – 0.77:1 for 2.8 seconds.
• Fail Case 2: The TCM commands 2nd gear when the engine torque is 36 – 350 Nm and the resulting gear ratio is
1.56:1 – 1.64:1 for 1 second.
Action Taken When the DTC Sets
• The TCM requests the ECM to illuminate the MIL during the second consecutive trip in which the conditions for
setting the DTC are met.
• The TCM inhibits 1st gear.
• The TCM commands maximum line pressure.
• The TCM freezes transmission adaptive functions.
• At the time of the first failure, the TCM records the operating conditions when the conditions for setting the DTC are
met. The TCM stores this information as a Failure Record.
• At the time of the second failure, the ECM records the operating conditions when the conditions for setting the DTC
are met. The ECM stores this information as a Freeze Frame.
• The TCM stores DTC P0756 in TCM history.
Conditions for Clearing the DTC
• The ECM turns off the MIL after the fourth consecutive drive trip in which the TCM does not send a MIL illumination
request.
• Tech 2 can clear the DTC.
• The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission
related diagnostic fault occurring.

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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–69
• The TCM cancels the DTC default actions when the ignition is off long enough to power down the TCM.
Diagnostic Aids
•
If you clear DTC P0756, and then cannot reset DTC P0756, the following conditions may exist:
• Fluid contamination,
• Blocked fluid circuits, or
• Restricted fluid circuits.
• Refer to 5.6 Shift Solenoid Valve State and Gear Ratio.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 This step tests the TCM commanded all shifts, all shift solenoid valves responded correctly, and if all the shifts did not occur.
3 Checks the mechanical components that cause the DTC and their state.
DTC P0756 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.7 Diagnostic System Check
2 1 Connect Tech 2 to the DLC.
2 Turn on the ignition, with the engine off.
NOTE
Before clearing the DTC, use the Tech 2 Freeze
Frame/Failure Record to record the transmission
parameters at the time the DTC set. Using Tech 2 to clear
the DTC(s) erases the Freeze Frame/Failure Record
records from the TCM.
3 On Tech 2 select: Transmission / Automatic Transmission / Diagnostic
Trouble Codes / Freeze Frame.
4 Select the relevant DTC and note the parameters at the time of the DTC setting.
5 On Tech 2 select:
Diagnostic Trouble Codes / Clear Engine & Transmission
DTCs.
6 Follow the instructions on Tech 2 and clear the DTCs.
7 Drive the vehicle in D4 range under the following conditions:
• Accelerate the vehicle, and
• Ensure the TCM commands 1st, 2nd, 3rd and 4th gears.
Did you detect a 4-3-3-4 shift pattern? Go to Step 3 Refer to Diagnostic
Aids within this
Section

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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–70
Step Action Yes No
3 1 Inspect the shift solenoid/hydraulic circuit for the following
conditions:
• Debris or chips in the AFL oil passage.
• Debris or chips restricting oil flow in passage #29 of the
case or through the spacer plate gasket into the valve
body.
• A cracked 2-3 shift solenoid.
• A 2-3 shift valve which is stuck or hung up in the valve
body bore.
• A 2-3 shuttle valve which is stuck or hung up in its bore.
• Damaged seals on the shift solenoid valves. Perform the
shift solenoid leak test, refer to 7C3 Automatic
Transmission – 4L60E – Hydraulic and Mechanical
Diagnosis.
2 Clean and inspect the related valves, bores and the valve body for debris or contamination.
Did you find and correct the condition? Go to Step 4 —
4 Perform the following procedure to verify the repair:
1 On Tech 2 select: Diagnostic Trouble Codes / Clear Engine & Transmission
DTCs
2 Follow the instructions on Tech 2 and clear any DTCs.
3 Drive the vehicle in D4 range under the following conditions, only if traffic and road conditions permit:
• Hold the throttle at 40%, and
• Accelerate to 64 km/h.
4 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0756 set? Go to Step 2 Go to Step 5
5 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Does Tech 2 display any DTCs you have not diagnosed? Refer to
4.8 Diagnostic Trouble Code List System OK
When all diagnosis and repairs are completed, check the system for correct operation.
4.23 DTC P0757 – 2-3 Shift Solenoid Valve
Performance – No Third or Fourth Gear
DTC Description
This diagnostic procedure supports DTC P0757 2-3 Shift Solenoid (SS) Valve Performance – No Third or Fourth Gear.
Circuit Description
The 2-3 shift solenoid (SS) valve controls the fluid flow acting on the 2-3 shift valves. The 2-3 SS valve is a normally-
open exhaust valve that is used with the 1-2 SS valve to allow four different shifting combinations.
When the transmission control module (TCM) detects a 1-2-2-1 shift pattern, then DTC P0757 sets. DTC P0757 is a
type A DTC.
Refer to 2 W iring Diagrams and Connector Chart to aid in diagnosis.

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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–71
Conditions for Running the DTC
• No DTCs P0120, P0722, P0723, P0742, P0973, P0974, P0976, P0977 or P1815.
• The engine torque is 108 – 882 Nm.
• The engine run time is greater than 5 seconds.
• The transmission fluid temperature is 20 – 130°C.
• The throttle position is greater than 10 percent.
• The output shaft speed is greater than 150 r.p.m.
Conditions for Setting the DTC
The TCM commands 3rd gear and the resulting gear ratio is a 1.44:1 – 1.52:1, 1st gear, for 2.25 seconds.
Action Taken When the DTC Sets
• The TCM requests the ECM to illuminate the MIL during the second consecutive trip in which the conditions for
setting the DTC are met.
• The TCM commands maximum line pressure.
• The TCM freezes transmission adaptive functions.
• The TCM inhibits 4th gear.
• At the time of the first failure, the TCM records the operating conditions when the conditions for setting the DTC are
met. The TCM stores this information as a Failure Record.
• At the time of the second failure, the ECM records the operating conditions when the conditions for setting the DTC
are met. The ECM stores this information as a Freeze Frame.
• The TCM stores DTC P0757 in TCM history during the second consecutive trip in which the conditions for setting
the DTC are met.
Conditions for Clearing the DTC
• The ECM turns off the MIL after the fourth consecutive drive trip in which the TCM does not send a MIL illumination
request.
• Tech 2 can clear the DTC.
• The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission
related diagnostic fault occurring.
• The TCM cancels the DTC default actions when the ignition is off long enough to power down the TCM.
Diagnostic Aids
• If you clear DTC P0757, and then cannot reset DTC P0757, the following conditions may exist:
• Fluid contamination,
• Blocked fluid circuits, or
• Restricted fluid circuits.
• Refer to 5.6 Shift Solenoid Valve State and Gear Ratio.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 This step tests the TCM commanded all shifts, all shift solenoid valves responded correctly, and if all the shifts did not occur.
3 Checks the mechanical components that cause the DTC and their state.

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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–81
Action Taken When the DTC Sets
• The TCM requests the ECM to illuminate the MIL during the second consecutive trip in which the conditions for
setting the DTC are met.
• The TCM commands maximum line pressure.
• The TCM freezes transmission adaptive functions.
• The TCM inhibits TCC.
• The TCM inhibits 4th gear if in hot mode.
• At the time of the first failure, the TCM records the operating conditions when the conditions for setting the DTC are
met. The TCM stores this information as a Failure Record.
• At the time of the second failure, the ECM records the operating conditions when the conditions for setting the DTC
are met. The ECM stores this information as a Freeze Frame.
• The TCM stores DTC P0894 in TCM history during the second consecutive trip in which the conditions for setting
the DTC are met.
Conditions for Clearing the DTC
• The ECM turns off the MIL after the fourth consecutive drive trip in which the TCM does not send a MIL illumination
request.
• Tech 2 can clear the DTC.
• The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission
related diagnostic fault occurring.
• The TCM cancels the DTC default actions when the ignition is off long enough to power down the TCM.
Diagnostic Aids
•
Bronze material found in the transmission oil pan may indicate stator shaft bushing wear. If bushing wear is
suspected, inspect the stator shaft and the input, turbine, shaft for damage.
• Perform the Torque Converter Diagnosis Procedure, refer to 7C3 Automatic Transmission – 4L60E – Hydraulic and
Mechanical Diagnosis.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
3 Checks the torque converter for slippage while in a commanded lock-up state.
4-12 Checks the mechanical components that cause the DTC and their state.
13 W hen the TAP cells are cleared the TCM needs to relearn the TAP cells for the transmission. As such, when the vehicle is first driven, the shifts may be harsh. The transmission shifts should become smoother the more the
vehicle is driven until the TCM has relearned all TAP cells.
DTC P0894 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.7 Diagnostic System Check
2 Inspect for correct transmission fluid level, refer to 7C4 Automatic
Transmission – 4L60E – On-vehicle Servicing.
Did you perform the fluid checking procedure?
Go to Step 3 Check the
transmission fluid level, refer to
7C4 Automatic
Transmission –
4L60E – On-vehicle Servicing

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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–85
Step Action Yes No
11 Inspect the forward clutch assembly for the following conditions:
• worn clutch plates,
• porosity in the forward clutch piston,
• damaged forward clutch piston,
• missing forward clutch piston inner and outer seals,
• cut forward clutch piston inner and outer seals,
• damaged forward clutch piston inner and outer seals,
• missing input housing to forward clutch housing O-ring seal,
• cut input housing to forward clutch housing O-ring seal,
• damaged input housing to forward clutch housing O-ring seal,
• damaged forward clutch housing,
• damaged forward clutch housing retainer and ball assembly, and
• forward clutch housing retainer and ball assembly is not sealing,
refer to 7C5 Automatic Transmission – 4L60E – Unit Repair.
Did you find and correct the condition? Go to Step 13 Go to Step 12
12 Inspect the 3-4 clutch assembly for the following conditions:
• worn clutch plates,
• porosity in the 3-4 clutch piston,
• damaged 3-4 clutch piston,
• missing 3-4 clutch inner and outer seals,
• cut 3-4 clutch inner and outer seals,
• damaged 3-4 clutch inner and outer seals,
• damaged 3-4 clutch spring assembly,
• damaged 3-4 clutch apply ring,
• damaged piston seal grooves,
• blocked orifice cup plug, and
• missing orifice cup plug, refer to 7C5 Automatic Transmission –
4L60E – Unit Repair.
Did you find and correct the condition? Go to Step 13 Check for an
intermittent fault in the circuit, refer to
8A Electrical-Body and Chassis
13 1 Change the transmission fluid and filter.
2 Inspect for correct transmission fluid level, refer to 7C4 Automatic Transmission – 4L60E – On-vehicle Servicing.
3 Add new fluid as necessary.
NOTE
The Clear TAPS function will clear all adapt cells. This may
affect transmission performance. The TCM will update the
transmission adapt cell values as the vehicle is driven.
4 On Tech 2 select: Transmission / Programming / Reset TAP Cells
and follow Tech 2 instructions.
Did you complete the above procedure? Go to Step 14 —

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–89
Step Action Yes No
7 Using a multimeter set to measure resistance, probe between
connector C-96 pin 40 and a known ground.
Does the multimeter display greater than 250 k Ω? Go to Step 9 Go to Step 8
8 Using a multimeter, test between E-95 pin 2 & C-96 pin 40 and
E-95 pin 1 & C-96 pin 17 for the following:
• open circuit,
• short together, and
• short to ground.
Did you find any of the conditions tested? Repair or replace
the affected circuit
Go to Step 11 —
9 Using a multimeter, test between E-95 pin 1 & E-95 pin 2 and the
solenoid for a short to voltage.
Did you find and correct the condition? Go to Step 11 Go to Step 10
10 Replace the TCM, refer to 7C4 Automatic Transmission – 4L60E –
On-vehicle Servicing.
Did you complete the replacement? Go to Step 11 —
11 Perform the following procedure to verify the repair:
1 On Tech 2 select: Diagnostic Trouble Codes / Clear Engine & Transmission
DTCs.
2 Follow the instructions on Tech 2 and clear any DTCs.
3 On Tech 2 select: Data Display / Pressure Control Solenoid Data.
4 Start the engine and ensure the difference on Tech 2 between the PCS Actual Current and the PCS Desired Current is less
than 16 mA.
5 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0961 set? Go to Step 2 Go to Step 20
12 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Does Tech 2 display any DTCs you have not diagnosed? Refer to
4.8 Diagnostic Trouble Code List System OK
When all diagnosis and repairs are completed, check the
system for correct operation.
4.28 DTC P0973 – 1-2 Shift Solenoid Control
Circuit Low Voltage
DTC Description
This diagnostic procedure supports DTC P0973 1-2 Shift Solenoid (SS) Control Circuit Low Voltage.
Circuit Description
The 1-2 shift solenoid (SS) valve controls the fluid flow acting on the 1-2 and 3-4 shift valves. The solenoid is a normally-
open exhaust valve. W ith the 2-3 SS valve, the 1-2 SS valve allows four different shifting combinations. The solenoid
attaches to the control valve body within the transmission. The 1-2 SS valve receives ignition voltage through the ignition
voltage circuit. The transmission control module (TCM) controls the solenoid by providing the ground path on the 1-2 SS
valve control circuit.
When the TCM detects a continuous open or short to ground in the 1-2 SS valve circuit, then DTC P0973 sets.
DTC P0973 is a type B DTC.

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