Isuzu KB P190. Manual - part 1018

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. 

•  When diagnosing for a possible intermittent short or 

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 

 

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. 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

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

∼15Ω 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

∼15Ω 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. 

 

Was 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 — 

7A2-108  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 

 

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

 

DTC P2773 or 2774 (Flash Code 75) 

 

   

 

 

RTW77AMF000901 

 

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 or

not deciding failure. 

  (9) Throttle opening more than 2%. 

 

 

 (10) Throttle opening signal is not detecting failure or 

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)