2007 ISUZU KB P190 Timing

Battery Page 6D1-3–7

3 Diagnosis
3.1 Diagnostic Procedures
Introduction
This test is used to aid in diagnosing faults with the vehicle where the battery seems to be at fault.
W ith the increased use of electronic sensors and computer control, the battery is much more than just a component used
to start a car. Low battery voltage can:
• affect the operation of the vehicle control modules and cause driveability problems, and
• cause the control modules to set diagnostic trouble codes (DTCs).
For example if a control module senses low battery voltage, it may increase fuel injector timing to increase engine rpm to
increase the generator output.
Therefore consider the state of charge of the battery any time a customer complains of a driveability related problem.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
1 Checks the operator understands the safety precautions for working with batteries.
2 Checks if the vehicle is fitted with a battery of the correct specification.
3 Checks if the battery appears serviceable by performing the battery inspection procedure.
4 Checks if the battery loses charge over an extended period. If so the likely problem is excess current draw while the vehicles ignition is in the off position.
5 Checks the state of charge of the battery.
6 Checks if the battery is capable of delivering the required load by performing the load test procedure.
Diagnostic Table Notes
1 For all wiring harness fault diagnosis, refer to 8A Electrical Body & Chassis.
2 For wiring harness repairs, refer to 8A Electrical Body & Chassis.
3 Refer to 6D1 – 3 Battery – V6.
Diagnostic Table
Step Action Yes No
1
Have you read and understood the safety precautions for working with
batteries? Go to Step 2 Refer to 2
Safety Precautions
2 Check the battery fitted is the correct specification recommended for
the vehicle? Refer to 5 Specifications.
Is the battery the correct specification? Go to Step 3 Replace the battery
with the correct
specification
3 Perform the battery inspection, refer to 3.2 Battery Inspection.
Does the battery appear serviceable? Go to Step 4 Replace the battery,
refer to 4.1
Battery
4 Does the customer complain the battery loses charge if the engine is
not started for an extended period? Preform the battery
current draw test, refer to 3.5
Battery
Current Draw Test Go to Step 5

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Automatic Transmission – 4L60E – General Information Page 7C1–10
Transmission Control Module Operation
The TCM processes data every 10 milliseconds from various sensors, such as throttle position, vehicle speed, gear
range, temperature, engine load and other inputs. The TCM compares all its various inputs with the internal programming
and calibration of the TCM using this data, a signal is transmitted to the valve body shift solenoids, which activate the
shift valves for precise shift control. Shift points are therefore precisely controlled and are identical from vehicle to vehic le.
The TCM also control torque converter clutch apply and release.
Shift feel is also electronically controlled by the TCM, by signals sent to the variable force solenoid, which controls fluid
line pressure and it is this pressure that precisely determines how the shifts will feel. In this way, the TCM electronically
synchronises the engine and transmission into a single integrated powertrain system for optimum performance, shift
timing, fuel efficiency and emission control.
3.2 TCM Wiring Diagrams
For details of the transmission control module (TCM) wiring diagrams, refer to 8A Electrical-Body and Chassis.

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–15
• 2-3 Shift Data – Once this mode is selected, displays specific parameter information about the 2-3 shift solenoid
valve (shift solenoid B) and its circuits.
• 3-4 Shift Data – Once selected, displays information on 3-4 shift timing.
• 3-2 Downshift Data – Once selected, displays information on 3-2 downshift timing.
• Pressure Control Solenoid Data – Once selected, displays specific parameter information about the PC solenoid
and its circuits.
• Transmission Adapts – Once selected, it has further sub menus:
• 1-2 Adapt Data – In this mode Tech 2 continuously monitors and displays 1-2 TAP cell data parameters.
• 2-3 Adapt Data –In this mode Tech 2 continuously monitors and displays 2-3 TAP cell data parameters.
• 3-4 Adapt Data –In this mode Tech 2 continuously monitors and displays 3-4 TAP cell data parameters.
• Steady State Adapt Data – In this mode Tech 2 continuously monitors and displays Steady State TAP data
parameters.
• System Identification: In this mode, Tech 2 will display the transmission identification screen. The following items
will be displayed; Identifier, Partnumber, Hardware Partnumber, Alpha Code, Software Version Number, Software
Partnumber, VIN Digit 1-10, VIN Digit 11-17.
NOTE
Further information about the Data Display mode
and the data parameter is contained in
3.2 Data Display.
Snapshot
In this test mode, Tech 2 captures TCM data before and after a forced manual trigger.
Additional Functions
If Additional Functions is selected, a selections list is displayed which contains:
• System Identification – In this mode, Tech 2 will display the transmission identification screen. The following items
will be displayed; Identifier, Partnumber, Hardware Partnumber, Alpha Code, Software Version Number, Software
Partnumber.
Miscellaneous Tests
If Miscellaneous Functions is selected, a selections list is displayed which contains:
• TCC Solenoid –Tech 2 can command the TCC solenoid on and off. Tech 2 will display whether the TCC solenoid
is active or inactive.
• TCC PWN Solenoid – Tech 2 can command the TCC PWM solenoid on and off. Tech 2 will display whether the
TCC PWM solenoid is active or inactive and torque percentage.
• TCC Apply – Tech 2 can command the TCC on when the vehicle is above 50 km/h.
• Shift Solenoid A – Tech 2 can command the shift solenoid A (1-2 shift solenoid) on and off.
• Shift Solenoid B – Tech 2 can command the shift solenoid B (2-3 shift solenoid) on and off.
• 3/2 Downshift Solenoid – Tech 2 can command the 3/2 downshift solenoid (3-2 shift solenoid) on and off.
• Gear Control – Tech 2 can incrementally command shift solenoid states to correspond to relative gear states. The
TCM will only allow single shift increments or decrements and does not allow a shift if it causes the engine RPM to
exceed a calibrated limit.
• Pressure Control Solenoid – This function allows the user to control state of the pressure control solenoid in
increments of 100 mA.
NOTE
For operating parameters of the
Miscellaneous Test, refer to 3.4 Miscellaneous Tests.

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–19
Tech 2 Parameter Units Displayed Typical Data Value
Vehicle Speed km/h 0
Estimated Gear Ratio Ratio 8.00:1
3-4 Shift Data
Once this mode is selected, displays information on 3-4 shift timing.
3-4 Shift Data Parameters
For definitions of the parameters in this table, refer to 3.3 Tech 2 Data Definitions.
Tech 2 Parameter Units Displayed Typical Data Value
Shift Solenoid A On / Off Varies
Shift Solenoid B On / Off Varies
Commanded Gear 1,2,3,4 1
3-4 Shift Time Seconds Varies
3-4 Shift Error Seconds Varies
Throttle Position Percent Varies
Engine Speed RPM Varies
AT Input Speed N/A N/A
AT Output Speed RPM Varies
Vehicle Speed km/h 0
Estimated Gear Ratio Ratio 8.00:1
3-2 Downshift Data
Once this mode is selected, displays information on 3-2 downshift timing.
3-2 Downshift Data Parameters
For definitions of the parameters in this table, refer to 3.3 Tech 2 Data Definitions.
Tech 2 Parameter Units Displayed Typical Data Value
3-2 Downshift Solenoid On / Off Varies
Commanded Gear 1,2,3,4 1
3-2 Downshift Solenoid Circuit Open or Shorted / Short to Battery /
Okay Okay
Throttle Position
Percent Varies
Engine Speed RPM Varies
AT Input Speed N/A N/A
AT Output Speed RPM Varies
Vehicle Speed km/h 0
Estimated Gear Ratio Ratio 8.00:1
Pressure Control Solenoid Data
Displays specific parameter information about the PC solenoid and its circuits.

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–49
Step Action Yes No
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 Operate the vehicle under the following conditions:
• Turn on the ignition, with the engine off for at least
2 seconds.
• Start the vehicle and idle for 5 seconds.
• Drive in D4 from 0 – 60 km/h 8 times in 1 ignition cycle.
4 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0719 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.
4.15 DTC P0722 – Vehicle Speed Sensor
Circuit Low Voltage
DTC Description
This diagnostic procedure supports DTC P0722 Vehicle Speed Sensor Circuit Low Voltage.
Circuit Description
The vehicle speed sensor (VSS) provides vehicle speed information to the transmission control module (TCM). The VSS
is a permanent magnet generator. The sensor is mounted in the extension housing facing the rear internal gear which is
splined to the output shaft assembly. As the output shaft and internal gear rotate, the toothed rotor of the internal gear
produces AC voltage as the rotor teeth pass through the magnetic field of the sensor. The AC voltage level and the
number of pulses increase as the speed of the vehicle increases. The TCM converts the voltage to vehicle speed. The
TCM uses the output shaft speed signal to determine shift timing and torque converter clutch (TCC) scheduling.
If the TCM detects no vehicle speed when there is engine speed in a drive gear range, then DTC P0722 sets.
DTC P0722 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 P0723, P1810, P1815 or P1816.
• Ignition voltage is 8 – 18 V.
• TFT is -40°C – 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 is less than 50 r.p.m. for 3 seconds.

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–52
Step Action Yes No
6 1 Disconnect connector C-96 from the TCM.
2 Test circuits speed sensor circuits (between C-96 pin 16 and E-44 pin 2; C-96 pin 41 and E-44 pin 1) for the following
conditions:
• Short to ground
• Open circuit
• Short together
Did you find and correct the condition? Go to Step 9 Go to Step 8
7 Replace the vehicle speed sensor, refer to 7C4 Automatic
Transmission – 4L60E – On-vehicle Service.
Did you complete the replacement? Go to Step 9 —
8 Replace the TCM, refer to 7C4 Automatic Transmission – 4L60E –
On-vehicle Service.
Did you complete the replacement? Go to Step 9 —
9 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 Operate the vehicle so the transmission output speed is greater than 500 r.p.m. for 3 seconds.
4 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0722 set? Go to Step 2 Go to Step 9
10 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.
4.16 DTC P0723 – Vehicle Speed Sensor
Circuit Intermittent
DTC Description
This diagnostic procedure supports DTC P0723 Vehicle Speed Sensor Circuit Intermittent.
Circuit Description
The vehicle speed sensor (VSS) provides vehicle speed information to the transmission control module (TCM). The VSS
is a permanent magnet generator. The sensor is mounted in the extension housing facing the rear internal gear which is
splined to the output shaft assembly. As the output shaft and internal gear rotate, the toothed rotor of the internal gear
produces AC voltage as the rotor teeth pass through the magnetic field of the sensor. The AC voltage level and the
number of pulses increase as the speed of the vehicle increases. The TCM converts the voltage to vehicle speed. The
TCM uses the output shaft speed signal to determine shift timing and torque converter clutch (TCC) scheduling.
If the TCM detects an unrealistic drop in output shaft speed, DTC P0723 sets. DTC P0723 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, P1810, P1815 or P1816.

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–73
Step Action Yes No
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.
4.24 DTC P0787 – 3-2 Shift Solenoid Control
Circuit Low Voltage
DTC Description
This diagnostic procedure supports the following DTC:
DTC P0787 3-2 Shift Solenoid (SS) Control Circuit Low Voltage.
Circuit Description
The 3-2 shift solenoid (SS) valve is a normally-closed, 3-port, on/off device that controls the 3-2 downshift. The solenoid
attaches to the control valve body within the transmission. The solenoid receives ignition voltage through the ignition
circuit. The transmission control module (TCM) controls the solenoid by providing a ground path on the 3-2 shift solenoid
valve control circuit. During a 3-2 downshift, the 2-4 band applies as the 3-4 clutch releases. The TCM varies the timing
between the 3-4 clutch release and the 2-4 band apply depending on the vehicle speed and the throttle position.
When the TCM detects a continuous open or short to ground in the 3-2 SS valve circuit, then DTC P0787 sets.
DTC P0787 is a type A DTC.
Refer to 2 W iring Diagrams and Connector Chart to aid in diagnosis.
Conditions for Running the DTC
• The system voltage is 10 – 18 V.
• The engine speed is greater than 450 r.p.m. for 5 seconds.
• Vehicle speed is less than 200 km/h.
Conditions for Setting the DTC
The TCM commands the solenoid off and the voltage feedback remains low, 0 V.
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 commands 3rd gear.
• The TCM inhibits TCC engagement.
• 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 P0787 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.

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–77
Step Action Yes No
When all diagnosis and repairs are completed, check the system for correct operation.
4.25 DTC P0788 – 3-2 Shift Solenoid Control
Circuit High Voltage
DTC Description
This diagnostic procedure supports DTC P0788 3-2 Shift Solenoid (SS) Control Circuit High Voltage.
Circuit Description
The 3-2 shift solenoid (SS) valve is a normally-closed, 3-port, on/off device that controls the 3-2 downshift. The solenoid
attaches to the control valve body within the transmission. The solenoid receives ignition voltage through the ignition 1
circuit. The transmission control module (TCM) controls the solenoid by providing a ground path on the 3-2 shift solenoid
valve control circuit. During a 3-2 downshift, the 2-4 band applies as the 3-4 clutch releases. The TCM varies the timing
between the 3-4 clutch release and the 2-4 band apply depending on the vehicle speed and the throttle position.
When the TCM detects a continuous short to voltage in the 3-2 shift solenoid valve control circuit, then DTC P0788 sets.
DTC P0788 is a type A DTC.
Refer to 2 W iring Diagrams and Connector Chart to aid in diagnosis.
Conditions for Running the DTC
• The system voltage is 10 – 18 V.
• The engine speed is 450 r.p.m. for 5 seconds.
• The engine is not in fuel cut off.
Conditions for Setting the DTC
DTC P0788 sets if the TCM commands the solenoid on and the voltage feedback remains high, battery voltage.
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 commands 3rd gear.
• The TCM inhibits TCC engagement.
• 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 P0788 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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