Isuzu N-Series. Manual - part 906

Transmission Control System (Smoother) 7A-79

1. Test the signal circuit between the TCM (pin 4

of B-427 connector) and the turbine speed
sensor harness connector (pin 2 of J-232
connector) for the following conditions:

• An open circuit
• A short to ground
• A short to the low reference
• High resistance

2. Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 18

Go to Step 14

1. Test the low reference circuit between the

TCM (pin 10 of B-427 connector) and the
turbine speed sensor harness connector (pin 1
of J-232 connector) for an open circuit or high
resistance.

2. Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 18

Go to Step 14

1. Turn OFF the ignition.
2. Inspect for an intermittent and for poor

connections at the harness connector of the
turbine speed sensor (pins 1 and 2 of J-232
connector).

3. Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 18

Go to Step 15

1. Turn OFF the ignition.
2. Disconnect the TCM harness connector.
3. Inspect for an intermittent and for poor

connections on the turbine speed sensor
circuits at the harness connector of the TCM
(pins 4 and 10 of B-427 connector).

4. Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 18

Go to Step 17

1. Remove the turbine speed sensor. Refer to

Turbine Speed Sensor Replacement in this
section.

2. Visually inspect the turbine speed sensor for

the following conditions:

• Physical damage
• Loose or improper installation

3. The following conditions may cause this DTC

to set:

• Excessive air gap between the turbine

speed sensor and the gearshift multi-plate
clutch case

• Electromagnetic interference in the turbine

speed sensor circuits

• Foreign material passing between the

turbine speed sensor and the gearshift
multi-plate clutch case

Did you find and correct the condition?

—

Go to Step 18

Go to Step 16

Replace the turbine speed sensor. Refer to Turbine
Speed Sensor Replacement in this section.

Did you complete the replacement?

—

Go to Step 18

—

Step

Action

Value(s)

Yes

7A-80 Transmission Control System (Smoother)

Important:
Replacement TCM must be programmed and
learned.
Replace the TCM. Refer to Transmission Control
Module (TCM) Replacement in this section.

Did you complete the replacement?

—

Go to Step 18

—

1. Reconnect all previously disconnected

harness connector(s).

2. Clear the DTCs with the Tech 2.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Operate the vehicle within the Conditions for

Running the DTC.

Did the DTC fail this ignition?

—

Go to Step 2

Go to Step 19

Observe the DTC Information with the Tech 2.

Are there any DTCs that you have not diagnosed?

—

Go to Diagnostic

Trouble Code (DTC)

List

System OK

Step

Action

Value(s)

Yes

Transmission Control System (Smoother) 7A-81

P0717 (Flash Code 2)

Circuit Description
The input shaft speed sensor is located on left-hand side
of the transmission housing. The input shaft speed
sensor is a magnetic coil type sensor, which generates
an AC signal voltage based on the counter shaft
rotational speed. If the transmission control module
(TCM) detects no input shaft speed sensor signal during
the vehicle running, this DTC will set.
Condition for Running the DTC

• DTCs P0715, P0718, P0721, P0726, U0400 and

U0406 are not set.

• The ignition switch is ON.
• The ignition voltage is more than 20 volts.
• The emergency switch is OFF.
• The engine is running.
• The turbine speed is more than 500 RPM.
• The vehicle speed is more than 10 km/h (6 MPH).
• The gearshift clutch is commanded engage.

Condition for Setting the DTC

• The TCM detects that the input shaft speed sensor

pulses are not generated during vehicle running.

Action Taken When the DTC Sets

• The TCM illuminates the transmission warning

lamp when the diagnostic runs and fails.

• The TCM inhibits gear select & shift position

learning and half-clutch learning.

Condition for Clearing the DTC

• The TCM turns OFF the transmission warning

lamp when the diagnostic runs and does not fail.

• A current DTC clears when the diagnostic runs and

does not fail.

• A history 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.

• Electrical or magnetic interference may affect

intermittent condition.

• Ensure the sensor is tight and the counter shaft is

not damaged.

• If this DTC is present, poor shift quality (feel) will

appear.

Notice:

• If this DTC is present, the Input Shaft Speed

parameter on the Tech 2 will indicate estimated
value based on other inputs.

DTC P0717 (Flash Code 2)

Schematic Reference: Transmission Controls
Schematics
Connector End View Reference: Transmission
Controls Connector End Views or Transmission Control
Module (TCM) Connector End Views

Step

Action

Value(s)

Yes

Did you perform the Diagnostic System Check -
Transmission Controls?

—

Go to Step 2

Go to Diagnostic

System Check -

Transmission

Controls

1. Install the Tech 2.
2. Turn OFF the ignition for 30 seconds.
3. Lift the driving wheels or drive the vehicle.
4. Let the vehicle run within the Conditions for

Running the DTC.

5. Monitor the Diagnostic Trouble Code (DTC)

Information with the Tech 2.

Does the DTC fail this ignition?

—

Go to Step 3

Go to Diagnostic

Aids

1. Turn OFF the ignition.
2. Disconnect the input shaft speed sensor

harness connector.

3. Connect a DMM across the input shaft speed

sensor terminals.

4. Measure the resistance across the turbine

speed sensor.

Does the input shaft speed sensor resistance
measure within the specified range?

1.5 - 3.5k

Ω

Go to Step 4

Go to Step 16

7A-82 Transmission Control System (Smoother)

1. Connect a DMM across the input shaft speed

sensor terminals (measure sensor output
voltage).

2. Place the DMM on the AC volt scale.
3. Lift the driving wheels or drive the vehicle.
4. Let the vehicle run with a fixed gear.
5. Monitor the DMM while accelerating the

engine.

Does the DMM indicate an AC voltage increase in
accordance with an engine speed increase?

—

Go to Step 5

Go to Step 15

1. Connect a DMM between the signal circuit of

the input shaft speed sensor harness (pin 2 of
J-139 connector) and a known good ground.

2. Turn ON the ignition, with the engine OFF.

Is the DMM voltage more than the specified value?

5.5 volts

Go to Step 9

Go to Step 6

Is the DMM voltage more than the specified value at
Step 5?

4.5 volts

Go to Step 7

Go to Step 11

1. Connect a test lamp between the signal circuit

of the input shaft speed sensor harness (pin 2
of J-139 connector) and a known good ground.

2. Connect a DMM between the probe of the test

lamp and a known good ground.

3. Turn ON the ignition, with the engine OFF.

Is the DMM voltage more than the specified value?

4.5 volts

Go to Step 10

Go to Step 8

1. Connect a DMM across the signal circuit and

the low reference circuit of the input shaft
speed sensor harness (pins 1 and 2 of J-139
connector).

2. Turn ON the ignition, with the engine OFF.

Is the DMM voltage more than the specified value?

4.5 volts

Go to Step 13

Go to Step 12

Important:
The input shaft speed sensor may be damaged if the
sensor signal circuit is shorted to a voltage source.

1. Test the signal circuit between the

transmission control module (TCM) (pin 5 of B-
427 connector) and the input shaft speed
sensor connector (pin 2 of J-139 connector) for
a short to battery or ignition voltage.

2. Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 18

Go to Step 17

1. Test the signal circuit between the TCM (pin 5

of B-427 connector) and the input shaft speed
sensor harness connector (pin 2 of J-139
connector) for a short to any 5 volts reference
circuit.

2. Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 18

Go to Step 17

Step

Action

Value(s)

Yes

Content .. 904 905 906 907 ..