2007 ISUZU KB P190 ECU

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–28
7 Ensure that all wiring harness connectors are fitted correctly and secure.
8 W hen steam or pressure cleaning vehicle components, such as engines, transmissions, etc., do not direct the cleaning nozzle at any system electrical wiring harness connectors or components.
9 Do not clear any DTCs unless instructed.
10 The fault must be present when using the Diagnostic Trouble Code (DTC) Diagnostic Tables. Otherwise, misdiagnosis or replacement of good parts may occur.
11 Do not touch any electronic control module connector pins or soldered components on the circuit board. This is required to avoid the possibility of electrostatic discharge damage.
12 Use only the test equipment specified in the diagnostic tables, as other test equipment may give incorrect results or damage good components.
13 Electronic control modules are designed to withstand normal current draws associated with vehicle operation. However, the following fault conditions or incorrect test procedure may overload internal control module circuits and
irreparably damage the control module:
• A short to voltage fault condition in any of the control module low reference circuits may cause internal and/or
sensor damage. Therefore, any short to voltage fault condition in the control module low reference circuits
must be rectified before replacing a faulty component.
• A short to ground fault condition in any of the control module 5 volts reference circuits may cause internal
control module and/or sensor damage. Therefore, any short to ground fault condition in the control module 5
volt reference circuits must be rectified before replacing a faulty component.
• W hen using a test light to test an electrical circuit, do not use any of the control module low reference circuits
or 5 volts reference circuits as a reference point. Otherwise, excessive current draw from the test light may
damage the control module.
14 Disregard DTCs that set while performing the following diagnostic Steps:
• Using the Tech 2 output control function, or
• Disconnecting a control module system sensor connector then switching the ignition ON.
15 After completing the required diagnostics and service operations, road test the vehicle to ensure correct system operation.
4.4 Preliminary Checks
The Preliminary Checks is a set of visual and physical checks or inspections that may quickly identify a control module
system fault condition:
1 Refer to relevant Service Techlines for information regarding the fault condition.
2 Ensure that the battery is fully charged.
3 Inspect the battery connections for corrosion or a loose terminal.
4 Ensure that all relevant control module system related fuses are serviceable.
5 Inspect for incorrect aftermarket theft deterrent devices, lights or mobile phone installation.
6 Ensure that there is no speaker magnet positioned too close to any electronic module that contains relays.
7 Inspect the system wiring harness for proper connections, pinches or cuts.
8 Ensure that all control module related electrical wiring connectors are fitted correctly.
9 Inspect the control module ground connections for corrosion, loose terminal or incorrect position.
10 Ensure that the resistance between the control module housing and the battery ground cable is less than 0.5 ohms.
11 Check that the control module and its mounting bracket is secure.
12 Check all control module related components for correct installation.
13 Check the control module and related wiring harness routing to ensure that no rubbing or cutting of the wiring harness by sharp body components can occur.

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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–30
• records the operating condition at the time the diagnostic fails and stores this information in the Freeze Frame/
Failure Record.
Type B – Emission Related DTCs
The TCM takes the following actions when a Type B DTC runs and fails.
• On the first time a Type B DTC fails:
• sets a current Type B DTC that represents the fault condition, and
• records the operating conditions at the time the fault sets and stores this information in the Failure Records.
• On the second consecutive ignition cycle that a Type B DTC fails:
• illuminates the MIL, and
• records the operating condition at the time the diagnostic fails and stores this information in the Freeze
Frame/ Failure Record.
Conditions for Clearing Type A or Type B DTCs
• The current DTC clears when there is no fault condition in the current TCM self-diagnostics.
• If there are no DTCs logged after six consecutive ignition cycles, the TCM deactivates the MIL.
• Type A or Type B History DTC clears when there is no fault condition after 40 consecutive warm-up cycles.
• Use of Tech 2 to clear DTCs.
Type C – Non-emission Related DTCs
The TCM takes the following action when a Type C DTC runs and fails:
• sets a current Type C DTC that represents the fault condition,
• records the operating conditions at the time the DTC is logged and stores this information in the Failure Record,
and
NOTE
The MIL does not illuminate when a Type C DTC
sets.
Conditions for Clearing Type C DTCs
• The current DTC clears when there is no fault condition in the current TCM self-diagnostics.
• Type C History DTC clears when there is no fault condition after 40 consecutive warm-up cycles.
• Use of Tech 2 to clear DTCs.
Current DTCs
A DTC is a Current DTC if the fault condition that triggers the DTC is present during the last TCM self-diagnostics.
History DTCs
A DTC is a History DTC if the fault condition that triggers the DTC is not present during the last TCM self-diagnostics.
4.7 Diagnostic System Check
Description
This section procedure is organised in a logical structure that begins with the diagnostic system check. The diagnostic
system check directs you in a logical direction to the appropriate Section or diagnostic procedure.

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–42
Action Taken When the DTC Sets
• The TCM requests the ECM to illuminate the MIL.
• The TCM allows the vehicle to operate in transmission protection mode.
• The TCM records the operating conditions when the conditions for setting the DTC are met. The TCM stores this
information as a Failure Record.
• The ECM records the operating conditions when the conditions for setting the DTC are met. The ECM stores this
information as a Freeze Frame.
Conditions for Clearing the DTC
• The ECM turns off the MIL after the third 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 an emission-related
diagnostic fault occurring.
• The TCM cancels the DTC default actions when the ignition is off long enough to power down the TCM.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 DTC P0602 indicates the TCM is not programmed.
DTC P0601 to P0604 or P1621 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.
3 On Tech 2 select: Transmission / Automatic Transmission / Diagnostic
Trouble Codes / Read DTC Information.
Has DTC P0602 set? Go to Step 3 Go to Step 4
3 1 On Tech 2 select:
Diagnostic Trouble Codes / Clear Engine & Transmission
DTCs
2 Follow the instructions on Tech 2 and clear any DTCs.
3 Program the TCM, refer to 7C4 Automatic Transmission – 4L60E – On-vehicle Servicing.
4 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0602 set? Go to Step 4 Go to Step 5
4 Replace the TCM, refer to 7C4 Automatic Transmission – 4L60E –
On-vehicle Servicing.
Did you complete the replacement? Go to Step 5 —

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–50
Action Taken When the DTC Sets
• The TCM illuminates 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 calculates vehicle speed from the automatic transmission engine r.p.m. and commanded 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 P0722 in TCM history.
Conditions for Clearing the DTC
• The ECM turns off the MIL after the sixth 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 an emission related
diagnostic fault occurring.
• The TCM cancels the default actions when the ignition is off long enough to power down the TCM.
Diagnostic Aids
• Inspect the rear internal gear teeth for damage.
• Visually inspect the VSS for cracks or damage.
• Ensure the VSS is properly torqued to the extension housing.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 Disable the traction control system when performing this step. W hen the ignition key is cycled off and then cycled back on, the traction control system defaults to on.
3 Checks the VSS for correct resistance.
4 Checks if the VSS and associated circuits are shorted to ground.
5 Checks the VSS produces an AC voltage when the output shaft is rotated.
6 Checks the integrity of the circuits between the TCM and the VSS.
DTC P0722 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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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–53
• Ignition voltage is 8 – 18 V.
• TFT is -40°C and 150°C.
• The engine run time is greater than 5 seconds.
• The throttle position is greater than 12 percent.
• The engine torque is 108 – 882 Nm.
Conditions for Setting the DTC
The transmission output shaft speed drops greater than 1,000 r.p.m. for at least 3.4 seconds.
Action Taken When the DTC Sets
• The TCM illuminates 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 calculates vehicle speed from the automatic transmission input shaft speed sensor and commanded 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 P0723 in TCM history.
Conditions for Clearing the DTC
• The ECM turns off the MIL after the sixth 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 an emission related
diagnostic fault occurring.
• The TCM cancels the default actions when the ignition is off long enough to power down the TCM.
Diagnostic Aids
•
Inspect the rear internal gear teeth for damage.
• Visually inspect the VSS for cracks or damage.
• Ensure the VSS is properly torqued to the transmission housing.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 Disable the traction control system when performing this step. W hen the ignition key is cycled off and then cycled back on, the traction control system defaults to on.
3 Checks the VSS for correct resistance.
4 Checks if the VSS and associated circuits are shorted to ground.
5 Checks the VSS produces an AC voltage when the output shaft is rotated.
6 Checks the integrity of the circuits between the TCM and the VSS.

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–58
Conditions for Running the DTC
• No DTCs P0722, P0723, P0742, P2763 or P2764.
• The IMS range is D2, D3 or D4.
• Ignition voltage is 8 – 18 V.
• The transmission fluid temperature is greater than 20°C.
• The engine torque is 108 – 881 Nm.
• The throttle position is greater than 10 percent.
• The gear ratio is within the following ranges:
• 1.41:1 – 1.56:1 — 2nd gear,
• 0.95:1 – 1.05:1 — 3rd gear.
• The TCC is commanded on 0.1 seconds.
• The TCC duty cycle is greater than 60 percent for more than 3 seconds.
Conditions for Setting the DTC
The TCM commands the TCC on, and the TCC slip is greater than 250 r.p.m. for 3 seconds.
Action Taken When the DTC Sets
•
The TCM requests the ECM to illuminate the MIL during the second consecutive drive trip in which the conditions
for setting the DTC are met.
• The TCM inhibits TCC.
• The TCM inhibits 4th gear if the transmission is in Hot Mode.
• The TCM commands elevated 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 P0741 in TCM history.
Conditions for Clearing the DTC
• The ECM turns off the MIL after the sixth 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 default actions when the ignition is off long enough to power down the TCM.
Diagnostic Aids
• Inspect the transmission fluid lines to the radiator. The lines may be pinched, blocked or twisted.
• Contamination may cause the TCC apply valve to stick in the valve body.
• Internal damage to the torque converter may prevent TCC application.
Test Description
The following numbers refer to the step numbers in the diagnostic table:

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–61
• The vehicle speed is greater than 15 km/h.
• TCC is commanded off.
Conditions for Setting the DTC
The following conditions occur four times in one ignition cycle:
• The TCM commands the TCC off.
• The TCC slip is -15 – +15 r.p.m. for greater than 3 seconds.
Action Taken When the DTC Sets
•
The TCM requests the ECM to illuminate the MIL during the second consecutive drive trip in which the conditions
for setting the DTC are met.
• 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 P0742 in TCM history.
Conditions for Clearing the DTC
• The ECM turns off the MIL after the sixth 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 default actions when the ignition is off long enough to power down the TCM.
Diagnostic Aids
The TCC fluid hydraulically applies the TCC, possibly causing an engine stall, under the following conditions:
• The TCC is hydraulically stuck in the on position
• The parking brake is applied.
• Any gear range is selected.
• Contamination may cause the TCC apply valve to intermittently stick in the valve body.
• Internal damage in the torque converter may cause no TCC apply.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 This step tests the hydraulic state of the TCC. W hen the TCM commands the TCC solenoid valve off, the slip speed should increase.
3 Checks the mechanical components that cause the DTC and their state.
DTC P0742 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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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–63
4.20 DTC P0751 – 1-2 Shift Solenoid Valve
Performance – No First or Fourth Gear
DTC Description
This diagnostic procedure supports DTC P0751 1-2 Shift Solenoid (SS) Valve Performance – No First or Fourth Gear.
Circuit Description
The 1-2 shift solenoid (SS) valve controls the fluid flow acting on the 1-2 and 3-4 shift valves. The 1-2 SS valve is a
normally-open exhaust valve that is used with the 2-3 SS valve, to allow four different shifting combinations.
If the transmission control module (TCM) detects a 2-2-3-3 shift pattern, then DTC P0751 sets. DTC P0751 is a type B
DTC.
Refer to 2 W iring Diagrams and Connector Chart to aid in diagnosis.
Conditions for Running the DTC
• No DTCs P0722, P0723, P0742, P0894, P0973, P0974, P0976, P0977 or P1815.
• Ignition voltage is 8 – 18 V.
• The engine r.p.m. is 500 – 6,500 r.p.m. for greater than 5 seconds.
• The transmission fluid temperature is 20 – 130°C.
• The throttle position is greater than 10 percent.
• The input shaft speed is 200 – 6,800 r.p.m.
• The output shaft speed is greater than 100 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 and the resulting gear ratio is 1.44:1 – 1.50:1 for 2 seconds.
• Fail Case 2: The TCM commands 4th gear and the resulting gear ratio is 0.98:1 – 1.03:1 for 4 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.
• 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 P0751 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.

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