DTC CHECK ISUZU KB P190 2007 Workshop Repair Manual

7A2-102 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

Circuit/System Testing DTC P1790

Step Action Value(s) YES NO
1
W as the On-Board Diagnostic (OBD) System Check
performed? — Go to
Step 2 Go to OBD
System Check
2 1. Install a scan tool.
2. Turn “OFF” the ignition and keep the position for
more than 30 seconds.
3. Turn “ON” the ignition.
4. Check the DTC on a scan tool.

Does a scan tool indicate DTC P1791? — Go to
Step 3 Refer to
Diagnostic Aids
3 Perform the SPS for the TCM.
Is the action complete? — Go to
Step 4 —
4 Recheck the DTC on the scan tool.

Does the scan tool indicate DTC P1790? — Go to
Step 5 Go to Step 6
5 Replace the TCM.
Important: The replacement TCM must be
programmed (Refer to SPS for procedure).

Is the action complete? — Go to
Step 6 —
6 1. Reconnect all previously disconnected harness
connector(s).
2. Clear the DTCs with a scan tool.
3. Turn “OFF” the ignition.
4. Start the engine.
5. Operate the vehicle within the Conditions For Running the DTC. You may also operate the
vehicle within the conditions that you observed
from the Freeze Frame/ Failure Records.

Did the DTC fail this ignition? —
Go to Step 2 Go to Step 7
7 Observe the stored information, Capture info with a
scan tool.

Are there any DTCs that you have not diagnosed? —
Go to
Diagnostic
Trouble Code (DTC) List Verify repair


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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-103

DTC P1791 (Flash Code 62)
Description
DTC P1791 is recorded by TCM when there is
malfunction in the RAM.
Condition For Running The DTC
Execute only one time after ignition “ON”.
Condition For Setting The DTC
One of the following conditions are met two times
continuously.
• W rite Ox5a5a5a5a into RAM, and read value is not
same as Ox5a5a5a5a.
• W rite Oxa5a5a5a5 into RAM, and read value is not
same as Oxa5a5a5a5.
Action Taken The DTC Sets
• Check Trans “ON”.
• DTC stored.
• MIL request “ON”. (EURO 4 only)
Conditions For Clearing The DTC
• The DTC can be cleared from the TCM history by
using a scan tool.
• The DTC will be cleared from history when the vehicle has achieved 40 warm-up cycles without a
failure reported.
•
After more than 1 second has elapsed after the
ignition key has been turned “ON”, short between
No.11 and No.4 (ground) of DLC (Data Link
Connector). Then, after 1 second, but within 6
seconds, discontinue shorting.
Diagnostic Aids
• Inspect the wiring for poor electrical connection at the
TCM. Look for possible bent, backed out, deformed
or damaged terminals. Check for weak terminal
tension as well. Also check for a chafed wire that
could short to bare metal or other wiring. Inspect for a
broken wire inside the insulation.
• W hen diagnosing for a possible intermittent short o
r
open condition, move the wiring harness while
observing test equipment for a change.



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ISUZU KB P190 2007

7A2-104 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

Circuit/System Testing DTC P1791

Step Action Value(s) YES NO
1
W as the On-Board Diagnostic (OBD) System Check
performed? — Go to
Step 2 Go to OBD
System Check
2 1. Install a scan tool.
2. Turn “OFF” the ignition and keep the position for
more than 30 seconds.
3. Turn “ON” the ignition.
4. Check the DTC on the scan tool.

Does a scan tool indicate DTC P1791? — Go to
Step 3 Refer to
Diagnostic Aids
3 Replace the TCM.
Important: The replacement TCM must be
programmed (Refer to SPS for procedure).

Is the action complete? — Go to
Step 4 —
4 1. Reconnect all previously disconnected harness
connector(s).
2. Clear the DTCs with a scan tool.
3. Turn “OFF” the ignition.
4. Start the engine.
5. Operate the vehicle within the Conditions For Running the DTC. You may also operate the
vehicle within the conditions that you observed
from the Freeze Frame/ Failure Records.

Did the DTC fail this ignition? —
Go to Step 2 Go to Step 5
5 Observe the stored information, Capture info with a
scan tool.

Are there any DTCs that you have not diagnosed? —
Go to
Diagnostic
Trouble Code (DTC) List Verify repair


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ISUZU KB P190 2007

7A2-106 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

(4) All of the following conditions are met.
• Device Control is not operating.
• Disable Normal Communication is receiving enable.
• DTC Clear is not operating.
Condition For Setting The DTC
The TCM detects following conditions for 0.5 seconds
continuously at shifting.
• Voltage at connector pin is 0V when solenoid is “ON”.
(DTC P2769)
• Voltage at connector pin is ignition voltage when
solenoid is “OFF”. (DTC P2770)
Action Taken When The DTC Sets
• No L-up solenoid functional failure detection.
• No squat control. (DTC P2770)
• The TCM fixes to 1st gear when the vehicle speed is less than 10 km/h (6 mph).
• Check Trans “ON”.
• DTC stored.
• MIL request “ON”. (EURO 4 only)
Conditions For Clearing The DTC
•
The DTC can be cleared from the TCM history by
using a scan tool.
• The DTC will be cleared from history when the vehicle has achieved 40 warm-up cycles without a
failure reported.
•
After more than 1 second has elapsed after the
ignition key has been turned “ON”, short between
No.11 and No.5 (ground) of DLC (Data Link
Connector). Then, after 1 second, but within 6
seconds, discontinue shorting.
Diagnostic Aids
• Inspect the wiring for poor electrical connection at the
TCM. Look for possible bent, backed out, deformed
or damaged terminals. Check for weak terminal
tension as well. Also check for a chafed wire that
could short to bare metal or other wiring. Inspect for a
broken wire inside the insulation.
• W hen diagnosing for a possible intermittent short o
r
open condition, move the wiring harness while
observing test equipment for a change.
Circuit/System Testing DTC P2769 or P2770

Step Action Value(s) YES NO
1
W as the On-Board Diagnostic (OBD) System Check
performed? — Go to
Step 2 Go to OBD
System Check
2 1. Install a scan tool.
2. Start the engine.
3. Drive the vehicle in D position.
4. Accelerate the vehicle until the gear position
becomes the 4th.
5. Release the accelerator pedal and accelerate the vehicle until the gear position becomes the 4th
again.

Does a scan tool indicate DTC P2769 or P2770? — Go to
Step 3 Refer to
Diagnostic Aids

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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-107

Step Action Value(s) YES NO
3 1. Turn “ON” the ignition with the engine “ON”.
2. Place the selector lever in the “P” position.
3. Measure the voltage between terminal C94-5 and terminal C94-1 on the TCM pigtail connector by 5-
8840-0285-0 DMM.

Is the voltage specified value? 8∼16V Go to
Step 4 Go to Step 5
4 1. Turn “OFF” the ignition.
2. Disconnect the TCM connector (C-94).
3. Turn “ON” the ignition.
4. Measure the voltage between terminal C94-5 and
terminal C94-1 by 5-8840-0285-0 DMM.

Is the voltage specified value? 8∼16V Go to
Step 7 Go to Step 10
5 1. Turn “OFF” the ignition.
2. Measure the resistance between terminal C94-5
and body ground by 5-8840-0285-0 DMM.

Is the resistance specified value? 11
∼15 Ω Go to Step 9 Go to Step 6
6 1. Disconnect the automatic transmission connector
(E-54).
2. Measure the resistance between terminal E54-7
and body ground by 5-8840-0285-0 DMM.

Is the resistance specified value? 11
∼15 Ω Go to Step 7 Go to Step 8
7 1. Check for open or short in the wire between
terminal C94-5 and terminal E54-7.
2. Repair or replace the wire between terminal C94-5
and terminal E54-7.

Is the action complete? — Go to
Step 11 —
8 Replace the SL solenoid.

Is the action complete? — Go to
Step 11 —
9 1. Clear the DTC.
2. Perform the test-driving.
3. Check the DTC.

W as DTC P2769 or P2770 stored? — Go to
Step 10 Refer to
Diagnostic Aids
10 Replace the TCM.
Important: The replacement TCM must be
programmed (Refer to SPS for procedure).

Is the action complete? — Go to
Step 11 —

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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-109

DTC P2773 or 2774 (Flash Code 75)





RTW 77AMF000901

Condition For Running The DTC
All of the following conditions are met.
(1)
All of the following conditions are met for 2
seconds or more continuously.
• The supply voltage is more than 10.2 volts and less than 15.5 volts.
• DTC U2104 is not detecting failure or not deciding failure.
• DTC U2105 is not detecting failure or not deciding failure.
• Engine revolution signal is not detecting failure or not deciding.
• The engine revolution is more than 550 rpm.
(2) Not emergency mode.
(3) D, 3, 2, L position point is “ON”.
(4) Shift position signal is not detecting failure or not deciding failure.
(5) The vehicle speed is more than 29 km/h (18 mph) and less than 160 km/h (100 mph).
(6) Speed meter signal is detecting failure or not deciding failure.
(7) Output revolution rpm is more than 1500 rpm.
(8) Output revolution sensor is not detecting failure o
r
not deciding failure.
(9) Throttle opening more than 2%.

(10) Throttle opening signal is not detecting failure o
r
note deciding failure.
(11) All of the following conditions are met.
• Device Control is not operating.
• Disable Normal Communication is receiving enable.
• DTC Clear is not operating.
Condition For Setting The DTC
All of the following conditions are met for 10 seconds
continuously. (DTC P2773)
• Transfer 4L switch is “ON”.
• Transfer High judgment by transfer real gear ratio 0.9 < T/F Hi gear ratio < 1.1
All of the following conditions are met for 10 seconds
continuously. (DTC P2774)
• Transfer 4L switch is “OFF”.
• Transfer Low judgment by transfer real gear ratio 2.23 < T/F Low gear ratio < 2.73
Action Taken When The DTC Sets
• No shift solenoid functional failure detection.
• No L-up solenoid functional failure detection.
• MIL request “ON”.
• Check Trans “ON”.
• DTC stored.
• MIL request “ON”. (EURO 4 only)

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ISUZU KB P190 2007

7A2-110 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

Conditions For Clearing The DTC
• The DTC can be cleared from the TCM history by
using a scan tool.
• The DTC will be cleared from history when the vehicle has achieved 40 warm-up cycles without a
failure reported.
•
After more than 1 second has elapsed after the
ignition key has been turned “ON”, short between
No.11 and No.4 (ground) of DLC (Data Link
Connector). Then, after 1 second, but within 6
seconds, discontinue shorting.
Diagnostic Aids
• Inspect the wiring for poor electrical connection at the
TCM. Look for possible bent, backed out, deformed
or damaged terminals. Check for weak terminal
tension as well. Also check for a chafed wire that
could short to bare metal or other wiring. Inspect for a
broken wire inside the insulation.
• W hen diagnosing for a possible intermittent short o
r
open condition, move the wiring harness while
observing test equipment for a change.

Circuit/System Testing DTC P2773 or P2774
Step Action Value(s) YES NO
1
W as the On-Board Diagnostic (OBD)
System Check performed? — Go to
Step 2 Go to OBD
System Check
2 1. Install a scan tool.
2. Turn “ON” the ignition.
3. Review and record scan tool data.
4. Operate the vehicle within scan tool data.

Does a scan tool indicate DTC P2773 or P2774? — Go to
Step 3 Refer to
Diagnostic Aids
3 Observe the 4L signal data of the TCM on the scan tool.
1. Turn “ON” the ignition with engine “ON”.
2. Perform the road testing.
3. Check the 4L signal data on a scan tool.

W as the problem found? — Go to
Step 4 Refer to
Diagnostic Aids
4 Observe the 4L signal data of the TCM on a scan tool.
1. Turn “ON” the ignition with engine “ON”.
2. Perform the road testing.
3. Check the 4L signal data on a scan tool.

Is the 4L signal fixed “ON”? (DTC P2773) — Go to
Step 6 Go to Step 5
5 Observe the 4L signal data of the TCM on a scan tool.
1. Turn “ON” the ignition with engine “ON”.
2. Perform the road testing.
3. Check the 4L signal data on a scan tool.

Is the 4L signal fixed “OFF”? (DTC P2774) — Go to
Step 6 Go to Step 8
6 Replace or Repair the wire between the TCM terminal
C94-21 and the T/F control unit terminal C111-7.

Is the action complete? — Go to
Step 9 —

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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-113

(2) All of the following conditions are met.
• Device Control is not operating.
• Disable Normal Communication is receiving
enable.
• DTC Clear is not operating.

The following condition at ignition “OFF” form “ON” is
detected seven times in total in 1 cycle.
• Receiving BUS “OFF” information from CAN
controller.
Action Taken When The DTC Set
• Throttle judgment on torque reduction control, line
pressure control at stationary status, line pressure
reduction control at gear change and line pressure
reduction control at garage. (Throttle opening 100%)
• Line pressure FULL output.
• Throttle judgment on gear change control. (Throttle
opening 0%)
• No line pressure reduction control at gear change.
• No torque reduction control.
• No squat control.
• No slope control.
• No L-up control.
• Control Engine rpm at 7000rpm. (No inertia
calculation)
• Control actual torque at MAX.
• Control driver torque at MAX.
• Control engine coolant temperature at 80 °C (176 °F).
• No coast control.
• No 3rd Start mode control.
• No line pressure reduction control at garage.
• No output revolution sensor failure detection.
• No input revolution sensor failure detection.
• No selector position switch failure detection.
• No oil temperature sensor failure detection.
• No T/F Hi-Low SW failure detection.
• No speed mater signal failure detection.
• No throttle signal failure detection.
• No Engine torque signal failure detection.
• No engine coolant temperature signal failure
detection.
• No Engine revolution signal failure detection.
• No shift solenoid functional failure detection.
• No L-up solenoid functional failure detection.
• No DTC U2105 failure detection.
• Cancel engine rpm condition of prerequisite of suppl
y
voltage failure detection.
• Control vehicle speed of speed meter at 0km/h.
• No torque reduction at stall.
• No cruise control.
• No warm up control.
• DTC stored.
• Check Trans “ON”.
• MIL request “ON”. (EURO 4 only)
Conditions For Clearing The DTC
• The DTC can be cleared from the TCM history by
using a scan tool.
• The DTC will be cleared from history when the vehicle has achieved 40 warm-up cycles without a
failure reported.
•
After more than 1 second has elapsed after the
ignition key has been turned “ON”, short between
No.11 and No.4 (ground) of DLC (Data Link
Connector). Then, after 1 second, but within 6
seconds, discontinue shorting.
Diagnostic Aids
• Inspect the wiring for poor electrical connection at the
TCM. Look for possible bent, backed out, deformed
or damaged terminals. Check for weak terminal
tension as well. Also check for a chafed wire that
could short to bare metal or other wiring. Inspect for a
broken wire inside the insulation.
• W hen diagnosing for a possible intermittent short o
r
open condition, move the wiring harness while
observing test equipment for a change.
• Inspect the wiring for EMI (Electro-Magnetic
Interference). Check that all wires are properly routed
away from coil, and generator. Also check fo
r
improperly installed electrical options. W hen this test
is performed, turn “OFF” on electronic auto parts
switches to improperly for a noise preventing.


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TO MODEL INDEX
ISUZU KB P190 2007

7A2-114 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

Circuit/System Testing DTCU2104

Step Action Value(s) YES NO
1
W as the On-Board Diagnostic (OBD) System Check
performed? — Go to
Step 2 Go to OBD
System Check
2 1. Install a scan tool.
2. Turn “ON” the ignition.

Does a scan tool indicate DTC U2104? — Go to
Step 3 Refer to
Diagnostic Aids
3 Observe the data from the ECM on the scan tool.
W as the data from the ECM fixed or did not
synchronized? (throttle opening, engine speed, etc) — Go to step 4 Refer to
Diagnostic Aids
4 Check the wire between the TCM connector and the ECM connector by 5-8840-0285-0 DMM.
1. Turn “OFF” the ignition.
2. Disconnect the TCM connector.
3. Measure the resistance between terminal C94-7
and terminal C94-17.

Is the resistance specified value? About 60Ω Go to
Step 7 Go to Step 5
5 Check the resistance of the ECM.
1. Turn “OFF” the ignition.
2. Disconnect the ECM connector.
3. Measure the resistance between the ECM terminal
70 and the ECM terminal 71.

Is the resistance specified value? About 120ΩGo to step 6 Go to step 8
6 Replace or Repair the wire between the TCM
connector C94-7, 17 and the ECM connector E60-70,
71.

Is the action complete? — Go to step 9 —
7 Replace the TCM.
Important: The replacement TCM must be
programmed (Refer to SPS for procedure).

Is the action complete? — Go to step 9 —
8 Replace the ECM.
Important: The replacement ECM must be
programmed (Refer to SPS for procedure).

Is the action complete? — Go to step 9 —

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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-117

(3) All of the following conditions are met.
• Device Control is not operating.
• Disable Normal Communication is receiving
enable.
• DTC Clear is not operating.
(4) DTC U2104 is not detecting failure or not deciding failure.
Condition For Setting The DTC
Detection standard is met for 2.5 second continuously.
Detection standard:
If one or more ID sent from Engine Control Module
(ECM) is not completed receiving for 2 basic cycles
since last receiving completion.
Action Taken When The DTC Sets
• Throttle judgment on torque reduction control, line
pressure control at stationary status, line pressure
reduction control at gear change and line pressure
reduction control at garage. (Throttle opening 100%)
• Line pressure FULL output.
• Throttle judgment on gear change control (Throttle
opening 0%).
• No line pressure reduction control at gear change.
• No torque reduction control.
• No squat control.
• No slope control (keep mode).
• No L-up control.
• Control Engine rpm at 7000rpm (No inertia
calculation).
• Control actual torque at MAX.
• Control driver torque at MAX.
• Control engine coolant temperature at 80 °C (176 °F).
• No coast control.
• No 3rd Start mode control.
• No line pressure reduction control at garage.
• No output revolution sensor failure detection.
• No C-0 rev sensor failure detection.
• No selector position switch failure detection.
• No oil temperature sensor failure detection.
• No T/F Hi-Low SW failure detection (Execute T/F
judgment using only T/F-SW ).
• No speed mater signal failure detection.
• No throttle signal failure detection.
• No Engine torque signal failure detection.
• No engine coolant temperature signal failure
detection.
• No Engine revolution signal failure detection.
• No shift solenoid functional failure detection.
• No L-up solenoid functional failure detection.
• Cancel engine rpm condition of prerequisite of suppl
y
voltage failure detection.
• Control vehicle speed of speed meter at 0km/h.
• No torque reduction at stall.
• No cruise control.
• No warm up control.
• Check Trans “ON”.
• DTC stored.
• MIL request “ON”. (EURO 4 only)
Conditions For Clearing The DTC
• The DTC can be cleared from the TCM history by
using a scan tool.
• The DTC will be cleared from history when the vehicle has achieved 40 warm-up cycles without a
failure reported.
• After more than 1 second has elapsed after the ignition key has been turned “ON”, short between
No.11 and No.4 (ground) of DLC (Data Link
Connector). Then, after 1 second, but within 6
seconds, discontinue shorting.
Diagnostic Aids
• Inspect the wiring for poor electrical connection at the
TCM. Look for possible bent, backed out, deformed
or damaged terminals. Check for weak terminal
tension as well. Also check for a chafed wire that
could short to bare metal or other wiring. Inspect for a
broken wire inside the insulation.
• W hen diagnosing for a possible intermittent short o
r
open condition, move the wiring harness while
observing test equipment for a change.
• Inspect the wiring for EMI (Electro-Magnetic
Interference). Check that all wires are properly routed
away from coil, and generator. Also check fo
r
improperly installed electrical options. W hen this test
is performed, turn “OFF” on electronic auto parts
switches to improperly for a noise preventing.


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007