Isuzu KB P190. Manual - part 1009

7A2-70  TRANSMISSION CONTROL SYSTEM (AW30–40LE) 

 

Step Action  Value(s) 

YES 

NO 

7 

Replace the Torque converter (Refer to Section 7A4).

 

Is the action complete? 

— Go 

to 

Step 8 — 

8 

 

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 9 

9 

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 

 

TRANSMISSION CONTROL SYSTEM (AW30–40LE)  7A2-71 

 

DTC P0746 (Flash Code 45) 

 
 

 

 

 

 

 

RTW77ALF001501 

 

Circuit Description 

The pressure control solenoid is a PWM duty control 
solenoid located in the valve body. 

The pressure control solenoid is a Transmission 
Control Module (TCM)-controlled device used to 
regulate transmission throttle pressure by energizing 
current from the TCM. 

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. 

 

 

 

•  The supply voltage is more than 10.2 volts and 

less than 15.5 volts. 

  (2) Not emergency mode. 

  (3) All of the following conditions are met. 

 

•  Device Control is not operating. 

 

• Disable Normal Communication Service is 

receiving enable. 

 

•  DTC Clear is not operating. 

  (4) Pressure control solenoid is not detecting failure or 

not deciding failure. 

  (5) Feedback AD value keeps less than 1000 for 0.5 

seconds and also linear solenoid assured voltage 
keeps 10.5 volts for 0.5 seconds. 

 

7A2-72  TRANSMISSION CONTROL SYSTEM (AW30–40LE) 

 

Condition For Setting The DTC 

All of the following conditions are met. 

 

• Accumulation of feedback error current value is 

more than 8A. 

 

• Detect failure twice continuously. 

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. 

Action Taken When The DTC Sets 

 

• No L-up control. 

 

• No line pressure reduction control at gear change. 

 

• No squat control. 

 

 

 

• No slope control. 

 

• No torque reduction control. 

 

• No line pressure reduction control at garage. 

 

• Line pressure FULL output. 

 

• No shift solenoid functional failure detection. 

 

• No L-up solenoid functional failure detection. 

 

• Become emergency mode. 

 

• Check Trans "ON". 

 

• DTC stored. 

 

• MIL request "ON". (EURO 4 only) 

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. 

 

• When diagnosing for a possible intermittent short 

or open condition, move the wiring harness while 
observing test equipment for change. 

 

Circuit/System Testing DTC P0746 

Step Action  Value(s) 

YES 

NO 

1 

 

Was 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. Record a scan tool data. 

 4. Operate the vehicle within scan tool data. 

 

Does a scan tool indicate DTC P0746? 

— 

Go to Step 3 Refer 

to 

Diagnostic 

Aids 

3 

Perform the transmission fluid checking procedure. 

Refer to checking Transmission Fluid level and 
Condition in Automatic Transmission 7A section. 

If the problem found, repair or replace necessary. 

 

Was the problem found? 

— 

Go to Step 9 Go 

to 

Step 4 

TRANSMISSION CONTROL SYSTEM (AW30–40LE)  7A2-73 

 

Step Action  Value(s) 

YES 

NO 

4 

Measure the resistance of pressure control 
solenoid. 

 1. Turn “OFF” the ignition. 

 

2. 

Disconnect the automatic transmission 
connector and TCM connector. 

 

3. 

Measure the resistance between automatic 
transmission terminal E54-2 and automatic 
transmission terminal E54-6. 

 

Is the resistance specified value? 

5 to 5.6

Ω 

at 20

°C 

(68

°F) 

 

Go to Step 5 Go 

to 

Step 7 

5 

Measure the resistance of wire between terminal 
C94-2 and terminal C94-4. 

 1. Turn “OFF” the ignition. 

 2. Connect the automatic transmission connector. 

 3. Disconnect the TCM connector. 

 4. Measure the resistance between terminal C94-2 

and terminal C94-4. 

 

Is the resistance specified value? 

5 to 5.6

Ω 

at 20

°C 

(68

°F) 

Go to Step 8 Go 

to 

Step 6 

6 

Repair or Replace the wire between terminals C94-
2, 4 and terminals E54-6, 2. 

 

Is the action complete? 

— 

Go to Step 9 

— 

7 

Replace the pressure control solenoid. (valve body) 

 

Is the action complete? 

— 

Go to Step 9 

— 

8 

Replace the TCM. 

Important: The replacement TCM must be 
programmed (Refer to SPS for procedure). 

 

Is the action complete? 

— 

Go to Step 9 — 

9 

 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 10 

10 

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