instrument panel ISUZU TF SERIES 2004 Repair Manual
Page 3790 of 4264
7A3-34  ON-VEHICLE SERVICE (AW30 –40LE) 
 
Transmission Control Module (TCM)   
  
 
 RTW37ALF001801 
Removal 
Preparation:  
Disconnect negative (  –) battery cable.  
   1. Disconnect the TCM harness connectors.  
 2. Remove fixing nuts (2 pieces) and TCM with  bracket from the car.  
NOTE:  The TCM is fitted under instrument panel of the 
driver's compartment by means of two stud bolts.  
   3. Remove fixing nuts (2 pieces) and remove TCM 
from bracket.  
  
    
Installation 
To install, follow the removal steps in reverse order.  
  
  
  
  
Page 3952 of 4264
7A1-6  CONSTRUCTION AND FUNCTION 
ELECTRONIC CONTROL COMPONENTS LOCATION 
 
4WD Only  4WD Only
 Instrument panel (Meter)   
 
 
 
 
  
  
  
Speed meter (2WD Only)  
Shift position indicator lamp 
POWER DRIVE, 3rd START 
indicator lamp 
A/T OIL TEMP indicator lamp 
CHECK TRANS indicator lam
p 
    
 Brake pedal 
 
 
 
 
 
Brake Switch 
 Select lever  
  
 
 
 
 
 
 
  
Power Drive
, 3rd Start select switch 
 Transmission Control Module (TCM)
 Electrical source  
 
 
 
 
 
 
Ignition 
Battery voltage 
Speed sensor 
Turbine sensor 
Inhibitor switch 
ATF thermo sensor 
High clutch oil pressure switch 
2-4 brake oil pressure switch 
Low & Reverse brake oil pressure 
switch  
Line pressure solenoid  
Low clutch solenoid 
High clutch solenoid 
2-4 brake solenoid 
Low & Reverse brake solenoid 
Lock-up solenoid 
 Transmission 
 Transfer Control Module 
 Transfer 
 
 
  
  
4L mode switch 
 Engine 
 
 
 
 
Engine speed sensor 
Throttle Position Sensor 
 
 
 Engine Control Module (ECM)
 Data link connector  
Page 4083 of 4264
DIAGNOSIS (JR405E)  7A2-91 
SYMPTOM DIAGNOSIS 
 
Symptom Condition Description  
Oil Leak Breather  Oil leaks from breather. J1 
 Between engine and converter housing Oil leaks between engine and converter 
housing. J2 
 Between converter housing and main caseOil leaks between converter housing and 
main case. J3 
 Between main case and rear housing Oil leaks between main case and rear 
housing. J4 
 Oil pan Oil leaks from oil pan. J5 
 Manual shaft oil seal Oil leaks from manual shaft oil seal. J6 
 Oil cooler pipe  Oil leaks from oil cooler pipe joint. J7 
Other Transmission overheat You smell the transmission burning. Z1 
  The transmission smokes.  
 Mode lamp does not light up when the 
power mode or 3rd start mode is turned on
The mode lamp on the instrument panel 
does not light up though the power mode or 
3rd start mode is turned on with the ignition 
switch in ON position. 
Z2 
 Mode lamp lights up when the power mode 
or 3rd start mode is turned off 
The mode lamp on the instrument panel 
lights up though the power mode or 3rd start 
mode is turned off with the ignition switch in 
ON position. 
Z3 
 Oil temperature warning lamp lights up Sometimes, the oil temperature warning 
lamp lights up. Z4 
 Select lever feeling is faulty Select lever feeling is faulty. Z5 
 Poor fuel consumption Poor fuel consumption. Z6 
 Pattern select switch is faulty Shift pattern does not change though the 
pattern select switch is turned on. Z7 
 Oil is splashed during the running Oil is splashed during the running. Z8 
 Abnormal smell Abnormal smell. Z9 
 Oil quantity is low or high Oil quantity is low or high. Z10
 Abnormal oil pressure Oil pressure is low or high. Z11
 Reverse buzzer does not ring Reverse buzzer does not ring in R range. Z12
  
Page 4129 of 4264
DIAGNOSIS (JR405E)  7A2-137 
No. Z2: Mode Lamp (Power Drive or 3rd Start) Does Not Light Up 
When The Power Mode or 3rd Start Mode is Turned On 
 
Description: 
  The mode lamp on the instrument panel does not light up though the power mode or 3rd start mode is turned on 
with the ignition switch in ON position. 
 
Possible Cause: 
  Faulty mode select switch is considered. 
  Bulb burn out. 
 
 
No. Z3: Mode Lamp (Power Drive or 3rd Start) Lights Up When 
The Power Mode or 3rd Start Mode is Turned Off 
 
Description: 
  The mode lamp on the instrument panel lights up though the power mode or 3rd start mode is turned off with the 
ignition switch in ON position. 
 
Possible Cause: 
  Faulty mode select switch is considered. 
 
 
No. Z4: Oil Temperature Warning Lamp Lights up 
 
Description: 
  Sometimes, the oil temperature warning lamp lights up. 
 
Possible Cause: 
  When the vehicle is stuck in the mud or continues to accelerate under overload, and ATF temperature exceeds 
145 C, the oil temperature warning lamp lights up. 
  If the oil temperature warning lamp lights up under usual service condition, following causes are considered. 
  ATF level has increased for some fault. 
  Refer to "No. Z1: Transmission overheat". 
  Lights up due to error of the ATF oil thermo sensor. 
 
No. Z5: Select Lever Feeling is Faulty. 
 
Description: 
  Select lever feeling is faulty. 
 
Possible Cause: 
  Disordered select cable. 
  Disordered select lever. 
  Faulty Manual plate. 
 
 
  
Page 4156 of 4264
7A3-4  ON-VEHICLE SERVICE (JR405E) 
TRANSMISSION CONTROL MODULE (TCM) 
 
 
 
RTW37ALF001901 
 
Remove and Disconnect 
1.  Disconnect the negative battery cable. 
2.  Remove the connectors. 
3. Remove the fixing nuts and remove the TCM (1)
from the bracket. 
Note: 
The TCM is fitted under instrument panel of the driver’s 
compartment by means of three stud bolts. 
 
  
Install or Connect 
Follow the removal steps in the reverse order. Be 
absolutely sure that the connectors are securely 
fastened. 
AT CONT