2007 ISUZU KB P190 ignition

7A2-94 TRANSMISSION CONTROL SYSTEM (AW30–40LE)


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 P0973)
• Voltage at connector pin is ignition voltage when
solenoid is “OFF”. (DTC P0974)
Action Taken When The DTC Sets
• No L-up control.
• No line pressure reduction control at gear change.
• No torque reduction control.
• No squat control.
• No slope control.
• No line pressure reduction control at garage.
• No input revolution sensor failure detection.
• No shift solenoid failure detection.
• No L-up solenoid failure detection.
• Change to emergency mode.
• 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.

Circuit/System Testing DTC P0973 or P0974

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. Depress the brake pedal and place the select lever in D position.
4. Press the 3rd start switch. (Turn the 3rd start switch “ON”.)
5. Press the 3rd start switch again. (Turn the 3rd start switch “OFF”.)

Does a scan tool indicate DTC P0973 or P0974? — Go to
Step 3 Refer to
Diagnostic Aids
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 C94-16 and terminal C94-1 (GND) 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 10

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ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-95

Step Action Value(s) YES NO
4 1. Turn “OFF” the ignition.
2. Disconnect the TCM connector (C-94).
3. Turn “ON” the ignition.
4. Measure the voltage between terminal C94-16 and terminal C94-1 by 5-8840-0285-0 DMM.

Is the voltage specified value? 0V Go to
Step 5 Go to Step 7
5 1. Turn “OFF” the ignition.
2. Measure the resistance between terminal C94-16
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 E54-4
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 C94-16 and terminal E54-4.
2. Repair or replace the wire between terminal C94-
16 and terminal E54-4.

Is the action complete? — Go to
Step 11 —
8 Replace the S1 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 P0973 or P0974 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 —
11 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 12

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TO MODEL INDEX
ISUZU KB P190 2007

7A2-98 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

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 P0976)
• Voltage at connector pin is ignition voltage when
solenoid is “OFF”. (DTC P0977)
Action Taken When The DTC Sets
• No L-up control.
• No line pressure reduction control at gear change.
• No torque reduction control.
• No squat control.
• No slope control (keep mode).
• No line pressure reduction control at garage.
• No input revolution sensor failure detection.
• No shift solenoid failure detection.
• No L-up solenoid failure detection.
• Change to emergency mode.
• 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.

Circuit/System Testing DTC P0976 or P0977

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. Depress the brake pedal and place the select lever in D position.
4. Press the 3rd start switch. (Turn the 3rd start switch “ON”.)
5. Press the 3rd start switch again. (Turn the 3rd start switch “OFF”.)

Does a scan tool indicate DTC P0976 or P0977? — Go to
Step 3 Refer to
Diagnostic Aids
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 C94-15 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

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-99

Step Action Value(s) YES NO
4 1. Turn “OFF” the ignition.
2. Disconnect the TCM connector (C-94).
3. Turn “ON” the ignition.
4. Measure the voltage between terminal C94-15 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 C94-15
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 E54-8
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 C94-15 and terminal E54-8.
2. Repair or replace the wire between terminal C94-
15 and terminal E54-8.

Is the action complete? — Go to
Step 11 —
8 Replace the S2 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 P0976 or P0977 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

7A2-100 TRANSMISSION CONTROL SYSTEM (AW30–40LE)

Step Action Value(s) YES NO
11 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 12
12 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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TO MODEL INDEX
ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (AW30–40LE) 7A2-101

DTC P1790 (Flash Code 61)
Description
The electrically erasable programable read only
memory (EEPROM) is a permanent memory chip that is
physically solenoid within the TCM. The EEPROM
contans the program and the calibration information that
the TCM needs to control powertrain operation.
Unlike the PROM used in past applications, the
EEPROM is not replaceable. If the TCM is replaced, the
new TCM will need to be programmed. Equipment
containing the correct program and calibration for the
vehicle is required to program the TCM.
Condition For Running The DTC
ROM check sum calculation is completed.
Condition For Setting The DTC
Following condition is met twice since ignition “ON”.
• ROM check sum calculation result/check sum value saved in ROM.
Action Taken When The DTC Sets
• Change to emergency mode.
• 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.


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

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


BACK TO CHAPTER INDEX
TO MODEL INDEX
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.



BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007