2007 ISUZU KB P190 air condition

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–72
DTC P0757 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 1-2-2-1 shift pattern? Go to Step 3 Refer to Diagnostic
Aids within this
Section
3 Inspect the shift solenoid/hydraulic circuit for the following conditions:
• An internal malfunction
• Damaged seals on the shift solenoid valve. Perform the shift
solenoid leak test, refer to 7C3 Automatic Transmission – 4L60E
– Hydraulic and Mechanical Diagnosis.
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 15%, and
• Accelerate to 80 km/h.
4 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0757 set? Go to Step 2 Go to Step 5

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

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.

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–76
Step Action Yes No
11 1 Remove Tool No. J44152 from the transmission.
2 Gain access to the 3-2 SS and the control valve body wiring harness, refer to 7C4 Automatic Transmission – 4L60E – On-
vehicle Servicing.
3 Disconnect the internal connector from the 3-2 SS.
4 Using a multimeter set to measure resistance, probe between each of the 3-2 SS pins and the transmission case.
Does the multimeter display 250 k Ω in both instances? Replace the control
valve body wiring harness, refer to 7C4 Automatic
Transmission –
4L60E – On-vehicle Servicing.
Go to Step 18 Replace the 3-2
shift solenoid, refer to 7C4 Automatic
Transmission –
4L60E – On-vehicle Servicing.
Go to Step 18
12 Using a multimeter, test between E-95 pin 10 and C-107 pin 9 for a
short to ground.
Did you find and correct the condition? Go to Step 18 Go to Step 13
13 1 Gain access to the control valve body wiring harness, refer to
7C4 Automatic Transmission – 4L60E – On-vehicle Servicing.
2 Test for a short to ground in the control valve body wiring harness.
Did you find a short to ground condition? Replace the control
valve body wiring harness, refer to 7C4 Automatic
Transmission –
4L60E – On-vehicle Servicing.
Go to Step 18 Go to Step 14
14 1 Test each solenoid in the transmission for a short to ground,
refer to 8A Electrical-Body and Chassis.
2 Replace the faulty solenoid as necessary.
Did you complete the replacement? Go to Step 18 —
15 Using a multimeter, test between E-95 pin 11 and C-96 pin 14 for a
short to ground.
Did you find and correct the condition? Go to Step 18 Go to Step 17
16 Using a multimeter, test between E-95 pin 11 and C-96 pin 14 for an
open circuit.
Did you find and correct the condition? Go to Step 18 Go to Step 17
17 Replace the TCM, refer to 7C4 Automatic Transmission – 4L60E –
On-vehicle Servicing.
Did you complete the replacement? Go to Step 18
—
18 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 D3 or D4 and perform a 3-2 downshift. Ensure the 3-2 Downshift Solenoid parameter displays On
when the shift occurs.
5 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0787 set? Go to Step 2 Go to Step 19
19 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

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

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.

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–79
Step Action Yes No
4 1 Remove Tool No. J44152 from the transmission.
2 Gain access to the 3-2 SS and the control valve body wiring harness, refer to 7C4 Automatic Transmission – 4L60E – On-
vehicle Servicing.
3 Disconnect the internal connector from the 3-2 SS.
4 Using a multimeter set to measure resistance, probe across the 3-2 SS pins.
Does the multimeter display less than 20 Ω? Replace the 3-2 SS,
refer to
7C4 Automatic
Transmission –
4L60E – On-vehicle Servicing
Go to Step 7 Replace the control
valve body wiring harness, refer to 7C4 Automatic
Transmission –
4L60E – On-vehicle Servicing.
Go to Step 7
5 Using a multimeter, test between E-95 pin 11 and C-96 pin 14 for a
short to voltage.
Did you find and correct the condition? Go to Step 7 Go to Step 6
6 Replace the TCM, refer to 7C4 Automatic Transmission – 4L60E –
On-vehicle Servicing.
Did you complete the replacement? Go to Step 7 —
7 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 D3 or D4 and perform a 3-2 downshift. Ensure the 3-2 Downshift Solenoid parameter displays On
when the shift occurs and Off in all other instances
5 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0787 set? Go to Step 2 Go to Step 8
8 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.
4.26 DTC P0894 – Transmission Component
Slipping
DTC Description
This diagnostic procedure supports DTC P0894 Transmission Component Slipping.
Circuit Description
The transmission control module (TCM) monitors the difference between engine speed and transmission output speed.
In D3 drive range with the TCC engaged, the engine speed should closely match the transmission output speed. In D4
drive range, with the TCC engaged, the TCC slip speed should be -20 to +50 r.p.m.
W hen the TCM detects excessive TCC slip when the TCC should be engaged, then DTC P0894 sets. DTC P0894 is a
type B DTC.
Refer to 2 W iring Diagrams and Connector Chart to aid in diagnosis.

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–83
Step Action Yes No
5 1 Inspect the 1-2 shift solenoid (SS) valve for the following
conditions:
• internal malfunction, such as sediment or damage, and
• damaged seals, refer to 7C4 Automatic Transmission –
4L60E – On-vehicle Servicing.
2 Inspect the 2-3 shift solenoid (SS) valve for the following conditions:
• internal malfunction, such as sediment or damage, and
• damaged seals, refer to 7C4 Automatic Transmission –
4L60E – On-vehicle Servicing.
3 Inspect the 3-2 shift solenoid valve assembly for the following conditions:
• internal malfunction, such as sediment or damage, and
• damaged seals, 7C4 Automatic Transmission – 4L60E –
On-vehicle Servicing.
Did you find and correct the condition? Go to Step 14 Go to Step 6
6 Inspect the valve body assembly for the following conditions:
• stuck regulator apply valve, and
• scored regulator apply valve body, refer to 7C5 Automatic
Transmission – 4L60E – Unit Repair.
Did you find and correct the condition? Go to Step 13 Go to Step 7
7 Inspect the torque converter assembly for the following conditions:
• front stator shaft bushing for wear,
• stator roller clutch not holding, and
• external damage/leaks, refer to 7C5 Automatic Transmission –
4L60E – Unit Repair.
Did you find and correct the condition? Go to Step 13 Go to Step 8
8 Inspect the oil pump assembly for the following conditions:
• a stuck converter clutch valve,
• the converter clutch valve is assembled backwards,
• a incorrectly position converter clutch valve retaining ring,
• a cocked converter clutch outer valve spring,
• a incorrectly positioned pump to case gasket,
• restricted orifice cup plugs,
• damaged orifice cup plugs, and
• over-tightened, or unevenly tightened pump body to cover bolts,
refer to 7C5 Automatic Transmission – 4L60E – Unit Repair.
Did you find and correct the condition? Go to Step 13 Go to Step 9

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–84
Step Action Yes No
9 Inspect the input housing and shaft assembly for the following
conditions:
• cut turbine shaft O-ring seal,
• damaged turbine shaft O-ring seal,
• restricted turbine shaft retainer and ball assembly, and
• damaged turbine shaft retainer and ball assembly, refer to 7C5
Automatic Transmission – 4L60E – Unit Repair.
Did you find and correct the condition? Go to Step 13 Go to Step 10
10 1 Inspect the 2-4 band assembly for the following conditions:
• worn 2-4 band,
• damaged 2-4 band,
• incorrectly positioned 2-4 band,
• incorrectly assembled 2-4 band, and
• the band anchor pin is not engaged, refer to 7C5
Automatic Transmission – 4L60E – Unit Repair.
2 Inspect the 2-4 servo assembly for the following conditions:
• restricted apply passages in the 2-4 servo assembly,
• blocked apply passages in the 2-4 servo assembly,
• nicks or burrs on the 2nd apply piston pin,
• damaged 2nd apply piston pin,
• incorrect 2nd apply piston pin,
• nicks or burrs on the pin bore in the case,
• damaged fourth servo piston,
• incorrectly assembled fourth servo piston,
• damaged servo bore in the case,
• missing piston seals,
• cut piston seals,
• damaged piston seals,
• porosity in the pistons,
• porosity in the cover,
• porosity in the case,
• damaged piston seal grooves,
• plugged 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 Go to Step 11

BACK TO CHAPTER INDEX
TO MODEL INDEX
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 —

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007