2007 ISUZU KB P190 engine

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–24
Shift Solenoid B •
The TCM commands the 2-3 shift solenoid valve on and off. Tech 2’s Shift Solenoid B
parameter should match the commanded state. Tech 2’s Commanded Gear
parameter should correspond with the shift solenoid combination. Refer to
5.6 Shift Solenoid Valve State and Gear Ratio.
• When the ignition is on, and the engine is off, there no limits to this control. The
solenoid remains on until commanded off, and vice versa. W hen the test is exited, the
solenoid state is determined by the TCM.
• W hen the engine is running, the following control limits apply:
• Only sequential gear changes are allowed. For example, 1
st to 3rd is not allowed.
If a non-sequential gear change is attempted, the message Non-sequential
gear changes not allowed. Gear changes must be made in order appears
on Tech 2.
• The vehicle speed must be below a calibrated value. If the vehicle speed is too
high, the message Vehicle speed too high appears on Tech 2.
• The engine speed must be below a calibrated value. If the engine speed is too
high, the message Engine speed too high appears on Tech 2.
• Downshifts are allowed only when the vehicle speed is below a calibrated value.
If the vehicle speed is too high, the message Eng. is on and veh. speed to hi
for 3-2 or 2-1 downshift appears on Tech 2.
• The gear requested may not be greater than the current selected transmission
range (PRNDL). For example, third gear is not allowed if the transmission range
is D2. If the gear requested is greater than the current selected transmission
range, the message Eng. running and gear request is greater than the
current TR appears on Tech 2.
• The solenoid remains on until commanded off, and vice versa. W hen the test is
exited, the solenoid state is determined by the TCM.
3-2 Downshift Solenoid
• The TCM commands the 3-2 shift solenoid valve on and off. Tech 2’s 3-2 Downshift
Sol. parameter should match the commanded state.
• When the ignition is on, and the engine is off, there are no limits to this control. The
solenoid remains on until commanded off, and vice versa. W hen the test is exited, the
solenoid state is determined by the TCM.
• W hen the engine is running, the following control limits apply:
• The transmission range (PRNDL) must be Park or Neutral. If the transmission
range is not in Park or Neutral, the message : Engine running and
transmission range is not Park/Neutral appears on Tech 2.
• The solenoid remains on until commanded off, and vice versa. W hen the test is
exited, the solenoid state is determined by the TCM.
Clear TAPS
(Transmission Adaptive
Pressures) • The TCM clears (or resets) the TAP cells to the original base value.
• There are no limits to using this test. It may be performed with the engine running or
when the ignition is on, and the engine is off.

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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–25
PC Solenoid
• The TCM commands the current to the pressure control solenoid to control
transmission line pressure. As the current increases, the line pressure decreases. As
the current decreases, the line pressure increases. The current range is 0.00 – 1.10 A
and may be commanded in one-tenth of an amp increments.
• When the ignition is on, and the engine is off, the reference (commanded) amperage
may be controlled within calibrated limits. Tech 2’s parameter PCS Desired Current
changes by the parameter PCS Actual Current does not change. The reference
current remains until commanded otherwise.
• W hen the engine is running, the following control limits apply:
• W hen the transmission range is Park or Neutral, the reference (commanded)
current may be controlled within calibrated limits. The engine speed must be
less than 1,500 r.p.m. If the engine speed is great than 1,500 r.p.m, the
message TR in park/neutral and engine speed over 1,500 RPM appears on
Tech 2. Both Tech 2 parameters PCS Desired Current and PCS Actual Current
parameters change. Both current readings remain until commanded otherwise.
• W hen the transmission range is not in Park or Neutral, the reference current can
only be controlled less than the current determined by the TCM. The TCM does
not allow a value to be selected that may cause damage to the transmission. If
the requested amperage is more than allowed by the TCM, the message
Requested current for the PC Solenoid is too high appears on Tech 2.
• Transmission range DTCs must not be active. If a transmission range DTC is
active, the message Engine running with transmission DTC present appears
on Tech 2.
Gear Control
• The TCM commands upshifts and downshifts. Tech 2’s Commanded Gear parameter
should correspond with the shift solenoid combination. Refer to 5.6 Shift
Solenoid Valve State and Gear Ratio.
• When the ignition is on, and the engine is off, there are no limits to this control. The
Tech 2 shift solenoid states changes to match the Commanded Gear selected.
• W hen the engine is running, the following control limits apply:
• The TCM does not allow a shift if it causes the engine r.p.m. to exceed a
calibrated limit. If a gear is requested and the engine speed is too high, the
message Engine speed too high appears on Tech 2.
• The TCM does not allow a 3-2 or 2-1 downshift if the vehicle speed exceeds a
calibrated limit. If either downshift is requested and the vehicle speed is too high,
the message Eng. is on and veh. Speed too hi for 3-2 or 2-1 downshift
appears on Tech 2.
• The TCM does not allow a 4-3 downshift if this vehicle speed exceeds a
calibrated limit. If a 4-3 downshift is requested and the vehicle speed is too high,
the message Vehicle speed to high appears on Tech 2.
• The TCM does not allow an upshift if the vehicle speed exceeds a calibrated
limit. If an upshift is requested and the vehicle speed is too high, the message
Vehicle speed to high appears on Tech 2.
• The TCM does not allow an upshift that is greater than the current selected
transmission range (PRNDL). For example 3
rd gear is not allowed if the
transmission range is D2. If an upshift is requested that is greater than the
current selected transmission range, the message Eng. running and gear
request is greater than the current TR appears on Tech 2.

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–26
TCC Control Solenoid
• The TCM commands the duty cycle of the TCC PWM solenoid. The duty cycle is
represented by a percentage of on (energised) time. Approximately 90-100 percent
duty cycle represents an on (energised) commanded state. Zero percent represents
an off (non-energised) commanded state. Tech 2 TCC PW M Solenoid parameter
should match the commanded state.
• When the ignition is on, and the engine is off, there are no limits to this control. The
solenoid remains on (90-100 percent duty cycle) until commanded off (zero percent
duty cycle), and vice versa. When the test is exited, the solenoid duty cycle is
determined by the TCM.
• W hen the engine is running, the following control limits apply:
• If the transmission range is Park, and the transmission is in hot mode, the TCC
control solenoid may not be commanded off. If the solenoid is requested off, the
message TCC OFF command disabled in Hot Mode appears on Tech 2.
• The TCC control solenoid may not be commanded off for more than a calibrated
amount of time. If the solenoid is commanded off for a certain amount of time,
the message TCC OFF time has been exceeded appears on Tech 2.
TCC Apply
•
The TCM commands the TCC enable solenoid valve on and off. Tech 2’s TCC
Solenoid parameter should match the commended state.
• When the ignition is on, and the engine is off, there are no limits to this control. The
solenoid remains on until commanded off, and vice versa. W hen the test is exited, the
solenoid state is determined by the TCM.
• W hen the engine is running, the following control limits apply:
• If the transmission range is Park or Neutral, the TCC enable solenoid may not
be commanded off for more than a calibrated amount of time. If the solenoid is
commanded off for a certain amount of time, the message TCC OFF time has
been exceeded appears on Tech 2.
• If the transmission range is Park or Neutral and the TCC control solenoid duty
cycle is less than maximum capacity, the TCC solenoid may not be commanded
on. If the solenoid is requested on during these conditions, the message TCC
Control Solenoid is not set to maximum Pressure appears on Tech 2.
• If the TCC control solenoid duty cycle is less than maximum capacity, the TCC
solenoid may not be commanded on. If the solenoid is commanded on during
these conditions the message TCC Control Solenoid is not set to maximum
Pressure appears on Tech 2.
• If the transmission is in hot mode, the TCC solenoid may not be commanded off.
If the solenoid is requested off the message TCC OFF command disabled in
Hot Mode appears on the scan tool display.


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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–27
4 Diagnostics
4.1 Introduction
The transmission diagnostic procedure is organised in a logical structure that begins with the diagnostic system check
and as such must always be used as the starting point. The diagnostic system check directs the technician to the logical
steps necessary to diagnose a transmission driveability fault condition.
4.2 Basic Knowledge Required

A lack of basic understanding regarding
electronics, electrical wiring circuits and use
of electrical circuit testing tools when
performing any diagnostic procedure, could
result in incorrect diagnostic results or
damage to system components.
Understanding of the following is required to perform any of the diagnostic procedures detailed in this Service
Information:
• Basic electronics,
• Electrical wiring circuits,
• Electrical circuits testing, and
• Correct use of basic system diagnostic tools.
4.3 Diagnostic Precautions

When tests are required on connector
terminals, use the adapters in connector
adaptor kit J35616-C to prevent damage to
terminals.
The following precautions must be observed when performing all diagnostic procedures. Otherwise, incorrect diagnostic
results or damage to system components will occur:
1 Disconnection of the battery affects certain vehicle electronic systems.
2 Disconnect the battery negative lead when performing the following procedures:
• Disconnecting the electronic control module wiring harness connector/s or
• Charging the battery.
3 Disconnect the battery terminal ground lead and the electronic control module wiring harness connector before attempting any electric arc welding on the vehicle.
4 Do not start the engine if the battery terminal is not properly secured to the battery.
5 Do not disconnect or reconnect any of the following while the ignition is switched on or when the engine is running:
• Any electronic control module or system component electrical wiring connector, or
• Battery terminal leads.
6 Ensure that the correct procedure for disconnecting and connecting system electrical wiring harness connectors is always followed. For information on the correct procedure for disconnecting and connecting specific wiring
connectors, refer to 8A Electrical-Body and Chassis.

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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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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–33
DTC Type Description Diagnostic Table
P1816 B Transmission Fluid Pressure (TFP) Valve Position Switch
Indicates Park/Neutral (P/N) with Drive Ratio 4.32 DTC P1810, P1815 and
P1816 – Transmission Fluid Pressure
Position Switch
P2763 B Torque Converter Clutch (TCC) Pressure Control (PC)
Solenoid Control Circuit High Voltage 4.33 DTC P2763 – Torque
Converter Clutch Pressure Control
Solenoid Control Circuit High Voltage
P2764 B Torque Converter Clutch (TCC) Pressure Control (PC)
Solenoid Control Circuit Low Voltage 4.34 DTC P2764 – Torque
Converter Clutch Pressure Control
Solenoid Control Circuit Low Voltage
P2769 B Torque Converter Clutch (TCC) Enable Solenoid Control
Circuit Low Voltage 4.35 DTC P2769 – Torque
Converter Clutch Enable Solenoid
Control Circuit Low Voltage
P2770 B Torque Converter Clutch (TCC) Enable Solenoid Control
Circuit High Voltage 4.36 DTC P2770 – Torque
Converter Clutch Enable Solenoid
Control Circuit High Voltage
U0073 B ECM CAN Bus Error
4.37 DTC U0073 and U0100 –
CAN-Bus No Communication With
ECM (Engine Control Module)
U0100 B ECM CAN Bus Error
4.37 DTC U0073 and U0100 –
CAN-Bus No Communication With
ECM (Engine Control Module)
4.9 DTC P0218 – Transmission Fluid Overtemperature
DTC Description
This diagnostic procedure supports DTC P0218 Transmission Fluid Overtemperature.
Circuit Description
The flow of transmission fluid starts in the bottom pan and is drawn through the filter, control valve body assembly,
transmission case and into the oil pump assembly. The oil pump assembly pressurises the fluid and directs it to the
pressure regulator valve where it becomes the main supply of fluid to the various components and hydraulic circuits in
the transmission. Hot fluid exiting the torque converter flows through the converter clutch apply valve and into the
transmission cooler lines, to the oil cooler located in the vehicle radiator, and auxiliary cooler if equipped. From the cooler ,
fluid returns to cool and lubricate the front of the transmission. In forward drive ranges, D4 fluid from the manual valve is
routed through an orificed cup plug in the rear of the transmission case to feed the rear lube fluid circuit.
When the transmission control module (TCM) detects a high transmission fluid temperature (TFT) for a long period of
time, DTC P0218 sets. DTC P0218 is a type C DTC.
Refer to 2 W iring Diagrams and Connector Chart to aid in diagnosis.
Conditions for Running the DTC
• No DTCs P0711, P0712 or P0713.
• The ignition switch is on for 5 seconds.
Conditions for Setting the DTC
The TFT is greater than 130°C for 600 seconds (10 minutes).
Action Taken When the DTC Sets
•
The TCM does not request the ECM to illuminate the MIL.
• The TCM freezes transmission adapt functions.

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–34
• The TCM records the operating conditions when the conditions for setting the DTC are met. The TCM stores this
information as Failure Records.
• The TCM stores DTC P0218 in TCM history.
Conditions for Clearing the DTC
• 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 fault no longer exists and the DTC passes.
Diagnostic Aids
• Tech 2’s Transmission Fluid Temp. should rise steadily to a normal operating temperature, then stabilise.
• Ask about the customer's driving habits, trailer towing, etc. Trailer towing should occur in D3.
• Refer to Symptoms - Automatic Transmission in 7C3 Automatic Transmission – 4L60E – Hydraulic and Mechanical
Diagnosis.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 Low transmission fluid can cause the transmission to overheat.
3 This step inspects for airflow restrictions or damage, which may result in the transmission overheating.
4-5 Decreased line pressure will cause the transmission to overheat. The torque converter stator is the pump for the transmission fluid. If the torque converter is damaged, it may not be producing the required pressure.
DTC P0218 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 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 Perform the
transmission fluid
checking procedure, refer to
7C4 Automatic
Transmission –
4L60E – On-vehicle Servicing

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–35
Step Action Yes No
3 1 Inspect the engine cooling system and transmission cooling
system for the following conditions:
• Air flow restrictions
• Air flow blockage
• Debris
2 Inspect the transmission cooling system for damaged cooler lines.
3 Check the flow rate of the transmission fluid, refer to 7C4 Automatic Transmission – 4L60E – On-vehicle Servicing.
Did you find and correct the condition? Go to Step 6 Go to Step 4
4 Test for correct line pressure, refer to 7C3 Automatic Transmission –
4L60E – Hydraulic and Mechanical Diagnosis.
Did you find and correct the condition? Go to Step 6 Go to Step 5
5 Diagnose the torque converter stator, refer to 7C3 Automatic
Transmission – 4L60E – Hydraulic and Mechanical Diagnosis.
Did you find and correct the condition? Go to Step 6 Check for an
intermittent fault in the circuit, refer to
8A Electrical-Body
and Chassis
6 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 Start and idle the engine until it reaches normal operating temperature.
4 On Tech 2 select: Data Display / Transmission Data.
5 Drive the vehicle for 10 minutes.
6 On Tech 2, monitor the Transmission Fluid Temp. and ensure
it has stabilised and is less than 129°C.
7 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0218 set? Go to Step 2 Go to Step 7
7 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.
4.10 DTC P0562 – System Voltage Low
DTC Description
This diagnostic procedure supports DTC P0562 System Voltage Low.
Circuit Description
The transmission control module (TCM) continuously monitors the system voltage on the battery and ignition circuits.
Lower than normal voltage may be inadequate to operate the transmission control solenoids properly. Improper solenoid
operation may cause erratic transmission operation and tie-up conditions, which may result in internal damage.

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