2007 ISUZU KB P190 engine

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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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–54
DTC P0723 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 Raise and support the rear axle assembly, refer to 0A General Information.
8 Start the engine.
9 Disable the traction control system.
10 Place the transmission in D3 range.
11 With the drive wheels rotating, slowly accelerate to 2,000 r.p.m. and hold. Road test the vehicle if necessary.
12 On Tech 2 select: Data Display / Transmission Data.
W ith the drive wheels rotating, does the Tech 2 AT Output Speed
parameter drop or fluctuate more than 1,300 r.p.m.? Go to Step 3 Check for an
intermittent fault in the circuit, refer to
8A Electrical-Body and Chassis
3 1 Turn off the ignition.
2 Disconnect connector E-44 from the sensor.
3 Using a multimeter set to measure resistance, probe across the speed sensor pins 1 and 2.
Does the multimeter display 976 – 2354 Ω? Go to Step 4 Go to Step 7
4 1 Using a multimeter set to measure resistance, probe between
connector E-44 pin 1 and a known ground.
2 Using a multimeter set to measure resistance, probe between connector E-44 pin 2 and a known ground.
Does the multimeter display greater than 50 k Ω in both instances? Go to Step 5 Go to Step 7
5 1 Place the transmission in neutral.
2 Using a multimeter set to measure AC voltage, probe across the speed sensor pins 1 and 2.
3 Rotate a rear wheel by hand.
Does the multimeter display 0.3 V AC? Go to Step 6 Go to Step 7

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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–55
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,
• Short to battery,
• Open circuit, and
• 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 On Tech 2 select: Data Display / Transmission Data.
4 Operate the vehicle ensuring the transmission output speed drop is less than 500 r.p.m. for 2 seconds and output speed is
greater than 500 r.p.m.
5 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0723 set? Go to Step 2 Go to Step 10
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.
4.17 DTC P0724 – Brake Switch Circuit Low
Input (Stuck Off)
DTC Description
This diagnostic procedure supports DTC P0724 Brake Switch Circuit Low Voltage.
Circuit Description
The transmission control module receives a direct input from the stop lamp switch assembly. When the brake pedal is
pressed, 12 V is supplied to the TCM through connector C-96 pin 42.
When the TCM detects an open or short to ground on the stop lamp signal circuit during stopping then DTC P0724 sets.
DTC P0724 is a type C DTC.
Refer to 2 W iring Diagrams and Connector Chart to aid in diagnosis.

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–56
Conditions for Running the DTC
• No DTCs P0719, P0722 or P0723.
• The vehicle speed is greater than 40 km/h for 7 seconds, then 8 – 40 km/h for 5 seconds, then less than 8 km/h.
• Continuously eight times once the previous criteria have been met.
Conditions for Setting the DTC
The TCM detects an open or short to ground on the stop lamp switch signal circuit when the circuit should be high,
battery voltage.
Action Taken When the DTC Sets
• The TCM does not request the engine control module (ECM) to illuminate the MIL.
• The TCM records the operating conditions when the conditions for setting the DTC are met. The TCM records this
information as a Failure Record.
• The TCM stores DTC P0724 in TCM history.
Conditions for Clearing 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.
• Tech 2 can clear the DTC.
Diagnostic Aids

• Verify the brake pedal position sensor is
adjusted properly, refer to 8B Cruise
Control.
• Test drive the vehicle if a switch or circuit
condition cannot be located. An
intermittent condition may be duplicated
during a test drive.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
3 Checks if the stop lamp switch is serviceable.
4 Checks if there is a stop lamp switch signal to the TCM.
DTC P0724 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 On Tech 2 select: Engine / V6 Engine / Data Display / Cruise / Traction Data.
3 Turn on the ignition, with the engine off.
4 Press the brake pedal.
Does the Stop Lamp Pedal Switch parameter indicate
Active? Check for an
intermittent fault in the circuit, refer to
8A Electrical-Body and Chassis Go to Step 3

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–57
Step Action Yes No
3 Test the stop lamp switch assembly, refer to 8B Cruise Control.
Is the stop lamp switch assembly serviceable? Go to Step 4 Replace the stop
lamp switch assembly
4 1 Disconnect connector C-96 from the TCM.
2 Using a multimeter set to measure voltage, probe between harness connector C-96 pin 42 and a known ground.
3 Press the brake pedal.
Does the multimeter display battery voltage? Go to Step 5 Repair or replace
affected circuit
Go to Step 6
5 Replace the TCM, refer to 7C4 Automatic Transmission – 4L60E –
On-vehicle Servicing.
Did you complete the replacement? Go to Step 6 —
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 then brake, eight times in one
ignition cycle.
4 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0724 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.
4.18 DTC P0741 – Torque Converter Clutch
System – Stuck Off
DTC Description
This diagnostic procedure supports DTC P0741 Torque Converter Clutch (TCC) System - Stuck Off.
Circuit Description
The torque converter clutch (TCC) solenoid valve is a normally-open exhaust valve that is used with the torque converter
clutch pulse width modulation (TCC PWM) solenoid valve to control fluid acting on the converter clutch apply valve. The
TCC solenoid valve attaches to the transmission case assembly extending into the pump cover. W hen grounded by the
transmission control module (TCM), the TCC solenoid valve stops converter signal oil from exhausting. This causes
converter signal oil pressure to increase and move the converter clutch apply valve against spring force and into the
apply position. In this position, release fluid is open to an exhaust port and converter feed fluid fills the apply fluid circu it.
The converter feed fluid applies the TCC. When the TCM no longer provides a ground path, the TCC solenoid valve de-
energizes and apply fluid exhausts, releasing the TCC.
When the TCM detects high torque converter slip when the TCC is commanded off, then DTC P0741 sets. DTC P0741 is
a type B DTC.
Refer to 2 W iring Diagrams and Connector Chart to aid in diagnosis.

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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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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–59
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 P0741 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 On Tech 2 select: Automatic Transmission / Data Display / Transmission Data.
8 Drive the vehicle in the D4 drive range in second, third, or fourth gear under steady acceleration, with a TP angle at 20%.
On Tech 2, while TCC Solenoid status is On, is the TCC Slip Speed
within -20 to +20 RPM ? Refer to Diagnostic
Aids within this Section Go to Step 3
3 The TCC system is hydraulically stuck off. Inspect for the following
conditions:
• TCC PWM solenoid valve mechanically stuck in the off position
or leaking.
• TCC regulator apply valve stuck in the off position.
• TCC solenoid valve stuck in the off position or leaking.
• TCC enable valve stuck in the off position.
• Incorrectly aligned, damaged or leaking valve body gasket.
• Inspect the forward clutch input housing assembly for the input
shaft fluid seal ring leaking or worn.
Did you find and correct any of the above conditions? Go to Step 4 —

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–60
Step Action Yes No
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 On Tech 2 select: Automatic Transmission / Data Display / Transmission Data.
4 Drive the vehicle in D4 with the TCC on and the throttle above 10%. Ensure Tech 2 displays TCC Slip Speed between -25 to
+25 RPM for 3 seconds.
5 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0741 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.
4.19 DTC P0742 – Torque Converter Clutch
System – Stuck On
DTC Description
This diagnostic procedure supports DTC P0742 Torque Converter Clutch (TCC) System – Stuck On.
Circuit Description
The torque converter clutch (TCC) solenoid valve is a normally-open exhaust valve that is used with the torque converter
clutch pulse width modulation (TCC PWM) solenoid valve to control fluid acting on the converter clutch apply valve. The
TCC solenoid valve attaches to the transmission case assembly extending into the pump cover. W hen grounded by the
transmission control module (TCM), the TCC solenoid valve stops converter signal oil from exhausting. This causes
converter signal oil pressure to increase and move the converter clutch apply valve against spring force and into the
apply position. In this position, release fluid is open to an exhaust port and converter feed fluid fills the apply fluid circu it.
The converter feed fluid applies the TCC. When the TCM no longer provides a ground path, the TCC solenoid valve de-
energizes and apply fluid exhausts, releasing the TCC.
W hen the TCM detects low torque converter slip when the TCC is commanded off, then DTC P0742 sets. DTC P0742 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, P0741 P02763, P02764, P02769 or P02770.
• Ignition voltage is 8 – 18 V.
• The engine run time is greater than 5 seconds.
• The IMS range is D4.
• The transmission fluid temperature is 10 – 130°C.
• The engine speed is 500 – 6,500 r.p.m. for 5 seconds, then 800 – 4,400 r.p.m.
• The engine torque is 156 – 881 Nm.
• The throttle position is greater than 10 percent.
• The transmission is not in 1st gear and the gear ratio is 0.95:1 – 1.56:1.

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ISUZU KB P190 2007