start ISUZU KB P190 2007 Workshop Repair Manual

TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-69
101. Remove the transmission oil pan. Refer to
repair instructions (On-Vehicle Service).
2. Inspect the low clutch solenoid valve for the following conditions:
• Physical damage of solenoid valve
• Loose or improper installation of solenoid valve
3. Inspect for an intermittent and for a poor connection at the harness connector of the
low clutch solenoid valve or in-line harness
connector.
4. Inspect for an intermittent and for a poor connection of ground wire.
5. Test the control circuit between the low clutch solenoid valve and the in-line harness
connector (pin 3 of E-54 male side) for the
following conditions:
• An open circuit
• A short to ground
• A short to the other solenoid valve circuit
• High resistance
6. Repair the connection(s) or circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 11
11 Replace the low clutch solenoid valve. Refer to
repair instructions (On-Vehicle Service).
Did you complete the replacement? —
Go to Step 13 —
12 Important:
Replacement TCM must be
programmed.
Replace the TCM. Refer to TCM Replacement.
Did you complete the replacement? —
Go to Step 13 —
13 1. Reconnect all previously disconnected
components or harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Lift the driving wheels or drive the vehicle while observing the DTC Information with a
scan tool.
Did the DTC fail this ignition? —
Go to Step 4 Go to Step 14
14 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK
Step
Action Value(s)Yes No

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

7A2-70 TRANSMISSION CONTROL SYSTEM (JR405E)
DTC P1120 (Flash Code 22)
Circuit Description
The accelerator pedal position (APP) sensor is
mounted on the accelerator pedal control assembly.
The analogue APP signals are converted by the engine
control module (ECM) into a pulse width modulation
(PWM) signal. This converted signal is continually sent
from the ECM to the TCM to determine appropriate
shift points depending on the accelerator pedal
pressing amount. If the TCM fails to receive a PWM
signal from the ECM, this DTC will set.
Condition for Running the DTC • The ignition switch is ON.
Condition for Setting the DTC • The TCM detects that the APP PWM signal from the ECM is not being received.
Action Taken When the DTC Sets • The TCM blinks the Check Trans lamp when the diagnostic runs and fails.
During the vehicle running; • The TCM holds the last gear position when the
diagnostic runs and fails.
• The TCM inhibits lock up control.
After the vehicle stopped;
• The TCM stops all shift solenoid valves and fixes to the 3rd gear. If a fail-safe valve problem is
detected, the shift solenoid valves are not stopped
but gear is fixed to the 3rd gear.
• The TCM stops PC solenoid valve.
Condition for Clearing the DTC • The TCM turns OFF the Check Trans lamp when the diagnostic runs and does not fail.
• A current DTC clears when the diagnostic runs and does not fail.
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
Circuit/ System Testing DTC P1120
Step Action Value(s)Yes No
1 Did you perform the Diagnostic System Check -
Transmission Controls? —
Go to Step 2 Go to Diagnostic
System Check - Transmission
Controls
2 1. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Monitor the ENGINE DTC Information with a scan tool.
Is DTC P2621 or P2622 set? —
Go to Applicable DTC in engine
control section Go to Diagnostic
Aids

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

7A2-72 TRANSMISSION CONTROL SYSTEM (JR405E)
41. Remove the transmission oil pan. Refer to
repair instructions (On-Vehicle Service).
2. Inspect the low & reverse brake solenoid valve and transmission fluid pressure (TFP) switch
for the following conditions:
• Physical damage
• Loose or improper installation
3. Test the signal circuit between the low & reverse brake TFP switch and the in-line
harness connector (pin 12 of E-54 male side)
for a short to ground.
4. Repair the circuit(s) or replace as necessary.
Did you find and correct the condition? —
Go to Step 7 Go to Step 5
5 1. Remove the low & reverse brake solenoid
valve and TFP switch from the valve body
assembly and perform function check. Refer
to repair instructions (On-Vehicle Service).
2. Repair or replace as necessary.
Did you find and correct the condition? —
Go to Step 7 Go to Step 6
6 Repair or replace the valve body assembly. Refer
to repair instructions (On-Vehicle Service or Unit
Repair).
Did you complete the repair or replacement? —
Go to Step 7 —
7 1. Reconnect all previously disconnected
components or harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Drive the vehicle while observing the DTC Information with a scan tool.
Did the DTC fail this ignition? —
Go to Step 2 Go to Step 8
8 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK
Step
Action Value(s)Yes No

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

7A2-74 TRANSMISSION CONTROL SYSTEM (JR405E)
41. Remove the transmission oil pan. Refer to
repair instructions (On-Vehicle Service).
2. Inspect the 2-4 brake solenoid valve and transmission fluid pressure (TFP) switch for
the following conditions:
• Physical damage
• Loose or improper installation
3. Test the signal circuit between the 2-4 brake TFP switch and the in-line harness connector
(pin 7 of E-54 male side) for a short to ground
4. Repair the circuit(s) or replace as necessary.
Did you find and correct the condition? —
Go to Step 7 Go to Step 5
5 1. Remove the 2-4 brake solenoid valve and TFP
switch from the valve body assembly and
perform function check. Refer to repair
instructions (On-Vehicle Service).
2. Repair or replace as necessary.
Did you find and correct the condition? —
Go to Step 7 Go to Step 6
6 Repair or replace the valve body assembly. Refer
to repair instructions (On-Vehicle Service or Unit
Repair).
Did you complete the repair or replacement? —
Go to Step 7 —
7 1. Reconnect all previously disconnected
components or harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Drive the vehicle while observing the DTC Information with a scan tool.
Did the DTC fail this ignition? —
Go to Step 2 Go to Step 8
8 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK
Step
Action Value(s)Yes No

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-77
91. Remove the transmission oil pan. Refer to
repair instructions (On-Vehicle Service).
2. Inspect the low & reverse brake solenoid valve and transmission fluid pressure (TFP) switch
for the following conditions:
• Physical damage
• Loose or improper installation
3. Inspect for an intermittent and for a poor connection at the harness connector of the
low & reverse brake TFP switch or in-line
harness connector.
4. Test the signal circuit between the low & reverse brake TFP switch and the in-line
harness connector (pin 12 of E-54 male side)
for the following conditions:
• An open circuit
• A short to ground
• A short to the solenoid valve circuit
• High resistance
5. Repair the connection(s), circuit(s) or replace as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 10
10 1. Remove the low & reverse brake solenoid
valve and TFP switch from the valve body
assembly and perform function check. Refer
to repair instructions (On-Vehicle Service).
2. Repair or replace as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 11
11 Repair or replace the valve body assembly. Refer
to repair instructions (On-Vehicle Service or Unit
Repair).
Did you complete the repair or replacement? —
Go to Step 13 —
12 Important:
Replacement TCM must be
programmed.
Replace the TCM. Refer to TCM Replacement.
Did you complete the replacement? —
Go to Step 13 —
13 1. Reconnect all previously disconnected
components or harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Drive the vehicle while observing the DTC Information with a scan tool.
Did the DTC fail this ignition? —
Go to Step 2 Go to Step 14
14 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK
Step
Action Value(s)Yes No

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

7A2-80 TRANSMISSION CONTROL SYSTEM (JR405E)
91. Remove the transmission oil pan. Refer to
repair instructions (On-Vehicle Service).
2. Inspect the 2-4 brake solenoid valve and transmission fluid pressure (TFP) switch for
the following conditions:
• Physical damage
• Loose or improper installation
3. Inspect for an intermittent and for a poor connection at the harness connector of the 2-
4 brake TFP switch or in-line harness
connector.
4. Test the signal circuit between the 2-4 brake TFP switch and the in-line harness connector
(pin 7 of E-54 male side) for the following
conditions:
• An open circuit
• A short to ground
• A short to the solenoid valve circuit
• High resistance
5. Repair the connection(s), circuit(s) or replace as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 10
10 1. Remove the 2-4 brake solenoid valve and TFP
switch from the valve body assembly and
perform function check. Refer to repair
instructions (On-Vehicle Service).
2. Repair or replace as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 11
11 Repair or replace the valve body assembly. Refer
to repair instructions (On-Vehicle Service or Unit
Repair).
Did you complete the repair or replacement? —
Go to Step 13 —
12 Important:
Replacement TCM must be
programmed.
Replace the TCM. Refer to TCM Replacement.
Did you complete the replacement? —
Go to Step 13 —
13 1. Reconnect all previously disconnected
components or harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Drive the vehicle while observing the DTC Information with a scan tool.
Did the DTC fail this ignition? —
Go to Step 2 Go to Step 14
14 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK
Step
Action Value(s)Yes No

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-83
10Replace the TCC solenoid valve. Refer to repair
instructions (On-Vehicle Service).
Did you complete the replacement? —
Go to Step 12 —
11 Important:
Replacement TCM must be
programmed.
Replace the TCM. Refer to TCM Replacement.
Did you complete the replacement? —
Go to Step 12 —
12 1. Reconnect all previously disconnected
components or harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Drive the vehicle while observing the DTC Information with a scan tool.
Did the DTC fail this ignition? —
Go to Step 3 Go to Step 13
13 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK
Step
Action Value(s)Yes No

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

7A2-86 TRANSMISSION CONTROL SYSTEM (JR405E)
91. Remove the transmission oil pan. Refer to
repair instructions (On-Vehicle Service).
2. Inspect the high clutch solenoid valve and transmission fluid pressure (TFP) switch for
the following conditions:
• Physical damage
• Loose or improper installation
3. Inspect for an intermittent and for a poor connection at the harness connector of the
high clutch TFP switch or in-line harness
connector.
4. Test the signal circuit between the high clutch TFP switch and the in-line harness connector
(pin 1 of E-54 male side) for the following
conditions:
• An open circuit
• A short to ground
• A short to the solenoid valve circuit
• High resistance
5. Repair the connection(s), circuit(s) or replace as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 10
10 1. Remove the high clutch solenoid valve and
TFP switch from the valve body assembly and
perform function check. Refer to repair
instructions (On-Vehicle Service).
2. Repair or replace as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 11
11 Repair or replace the valve body assembly. Refer
to repair instructions (On-Vehicle Service or Unit
Repair).
Did you complete the repair or replacement? —
Go to Step 13 —
12 Important:
Replacement TCM must be
programmed.
Replace the TCM. Refer to TCM Replacement.
Did you complete the replacement? —
Go to Step 13 —
13 1. Reconnect all previously disconnected
components or harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Drive the vehicle while observing the DTC Information with a scan tool.
Did the DTC fail this ignition? —
Go to Step 2 Go to Step 14
14 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK
Step
Action Value(s)Yes No

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-87
DTC P1875 (Flash Code 25)
Circuit Description
The all shift solenoid valves feed drive voltage from the
TCM and low side circuit is connected to the TCM
through the ground return circuit. The TCM monitors
the ground return circuit through the feedback circuit. If
the TCM detects an improper status on the ground
return circuit, this DTC will set.
Condition for Running the DTC • The ignition switch is ON.
Condition for Setting the DTC • The TCM detects an open circuit on the ground return circuit.
Action Taken When the DTC Sets • The TCM blinks the Check Trans lamp when the diagnostic runs and fails.
• The TCM stops all shift solenoid valves and fixes to the 3rd gear. If a fail-safe valve problem is
detected, the shift solenoid valves are not stopped
but gear is fixed to the 3rd gear. • The TCM stops PC solenoid valve.
• The TCM inhibits lock up control.
Condition for Clearing the DTC • The TCM turns OFF the Check Trans lamp when the diagnostic runs and does not fail at next
ignition cycle.
• A current DTC clears when the diagnostic runs and does not fail at next ignition cycle.
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
Schematic Reference: Transmission Controls
Schematics
Connector End View Reference: Transmission
Controls Connector End Views or TCM Connector End
Views
Circuit/ System Testing DTC P1875
Step Action Value(s)Yes No
1 Did you perform the Diagnostic System Check -
Transmission Controls? —
Go to Step 2 Go to Diagnostic
System Check -
Transmission Controls
2 1. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Monitor the DTC Information with a scan tool.
Does the DTC fail this ignition? —
Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition.
2. Disconnect the in-line harness connector (E- 54) near the transmission range switch.
3. Connect a test lamp between the ground return circuit (pin 11 of E-54 male side) and
battery voltage.
Does the test lamp illuminate? —
Go to Step 4 Go to Step 7
4 1. Inspect for an intermittent and for a poor
connection at the in-line harness connector
(pin 11 of E-54).
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 9 Go to Step 5
5 1. Test the circuit between the TCM (pin 22 of C-
95) and the in-line harness connector (pin 11
of E-54 female side) for an open circuit or high
resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 9 Go to Step 6

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

7A2-88 TRANSMISSION CONTROL SYSTEM (JR405E)
61. Turn OFF the ignition.
2. Disconnect the TCM harness connector.
3. Inspect for an intermittent and for a poor connection at the harness connector of the
TCM (pin 22 of C-95).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 9 Go to Step 8
7 1. Remove the transmission oil pan. Refer to
repair instructions (On-Vehicle Service).
2. Inspect for an intermittent and for a poor connection at the ground terminal or in-line
harness connector. Clean or tighten grounds
as necessary.
3. Repair the open circuit or high between the ground terminal and the in-line harness
connector (pin 11 of E-54 male side).
Did you complete the repair? —
Go to Step 9 —
8 Important:
Replacement TCM must be
programmed.
Replace the TCM. Refer to TCM Replacement.
Did you complete the replacement? —
Go to Step 9 —
9 1. Reconnect all previously disconnected
components or harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
Did the DTC fail this ignition? —
Go to Step 3 Go to Step 10
10 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK
Step
Action Value(s)Yes No

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007