Isuzu KB P190. Service manual - part 1023

ON-VEHICLE SERVICE (AW30–40LE)  7A3-7 

 
 

 
 

 

 

 

7A3-8  ON-VEHICLE SERVICE (AW30–40LE) 

 
 

 
 

 

 

 
 

ON-VEHICLE SERVICE (AW30–40LE)  7A3-9 

Manual Shifting Test 

NOTE:  With this test, it can be determined whether the
trouble lies within the electrical circuit or is a mechanical
problem in the transmission. 

  1. Disconnect TCM connector 

  2. Inspect manual driving operation 

Check that the relation of the position between
select lever and gear corresponds to the following
table. 

If any abnormality is found in the above test, do
perform the stall, time lag or gear shift tests. 

 

 
 
 
 

 

 

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  3. Connect TCM connector 

With the engine off, connect the TCM connector. 

 
 

 

Stall Test 

 

 
 
 

 

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The object of this test is to check the overall
performance of the transmission and engine by
measuring the maximum engine speeds at the “D" and 
“R" positions. 

NOTE: 

  1. 

Perform the test at normal operating

fluid 

temperature (50 – 80

°C or 122 – 176°F). 

 2. Do not continuously run this test longer than 5 

seconds. 

 
 
 

 

7A3-10  ON-VEHICLE SERVICE (AW30–40LE) 

Measure Stall Speed 

  1. Chock the four wheels. 

  2. Mount an engine tachometer. 

  3. Fully apply the parking brake. 

  4. Step down strongly on the brake pedal with your left

foot. (Keep the state until the test is completed) 

  5. Start the engine. 

  6. Turn off the A/C. 

  7. Select into the “D" position. Step all the way down

on the accelerator pedal with your right foot. Quickly
record the highest speed as soon as the engine
speed gets stabilized. 

  8. Select into the “N” position and maintain the engine

idling condition more than 1 minute. 

Stall speed: 2300

±±±±200 rpm * 

 

 * Ambient temperature to be between roughly 10

°C 

(50

°F) and 40°C (104°F). 

Evaluation 

  1. If the engine speed is the same for both positions

but lower than the specified value: 

•  Engine output is insufficient. 

•  Stator one-way clutch is not operating properly. 

NOTE:  If more than 600 rpm below the specified value,
the torque converter could be faulty. 

  2. If the stall speed in “D" position is higher than

specified: 

•  Line pressure too low 

•  Forward clutch slipping 

•  No.2 one-way clutch not operating properly 

  3. If the stall speed in “R" position is higher than

specified: 

•  Line pressure too low 

•  Direct clutch slipping 

•  No.3 brake slipping 

  4. If the stall speed in the “R" and “D" positions are 

higher than specified: 

•  Line pressure too low 

•  Improper fluid level 

 

 

Time Lag Test 

 

 

 

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If the shift lever is shifted while the engine is idling,
there will be a certain time elapse or lag before the
shock can be felt. This is used for checking the
condition of the forward clutch, direct clutch, No.3
brake, and No.2 one-way clutch. 

NOTE: 

  1. 

Perform the test at normal operating

fluid 

temperature (50 – 80

°C or 122 – 176°F) 

  2. Be sure to allow one minute interval between tests.

 3. Make three measurements and take the average 

value.