Isuzu N-Series. Service manual - part 933

Transmission Control System (Smoother) 7A-187

1. Turn ON the ignition, with the engine OFF.
2. Observe the Emergency Switch parameter

with the Tech 2 while momentarily jumping 3-
amp fused jumper wire across the emergency
switch harness connector between pins 1 and
5 of the N-17 connector.

Does the Tech 2 indicate ON when the circuit is
jumpered and OFF when the circuit is not
jumpered?

—

Go to Step 7

Go to Step 6

Repair the open circuit or high resistance on the
voltage feed circuit between the Meter (10A) fuse
(F-16) in the glove box fuse block and the
emergency switch (pin 1 of N-17 connector).

Did you complete the repair?

—

Go to Step 36

—

1. Test the emergency switch signal circuit

between the TCM (pin 4 of B-428 connector)
and the emergency switch (pin 5 of N-17
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 36

Go to Step 8

1. Turn OFF the ignition.
2. Disconnect the emergency switch harness

connector.

3. Inspect for an intermittent and for poor

connections at the harness connector of the
emergency switch (pins 1 and 5 of N-17
connector).

4. Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 36

Go to Step 12

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

connection on the emergency switch circuit at
the harness connector of the TCM (pin 4 of B-
428 connector).

4. Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 36

Go to Step 35

1. Turn ON the ignition switch, with the engine

OFF.

2. Observe the Emergency Switch parameter

with the Tech 2.

Does the Emergency Switch parameter indicate
OFF when the switch is OFF?

—

Go to Intermittent

Conditions

Go to Step 10

1. Turn OFF the ignition.
2. Disconnect the emergency switch harness

connector.

3. Turn ON the ignition, with the engine OFF.
4. Observe the Emergency Switch parameter

with the Tech 2.

Does the Emergency Switch parameter indicate
OFF?

—

Go to Step 12

Go to Step 11

Step

Action

Value(s)

Yes

7A-188 Transmission Control System (Smoother)

1. Test the emergency switch circuit between the

TCM (pin 4 of B-428 connector) and the
emergency switch (pin 5 of N-17 connector) for
a short to ground.

2. Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 36

Go to Step 35

Replace emergency switch.

Did you complete the replacement?

—

Go to Step 36

—

1. Turn ON the ignition switch, with the engine

OFF.

2. Observe the Emergency 1st Switch parameter

with the Tech 2.

Does the Emergency 1st Switch parameter indicate
ON when the switch is 1?

—

Go to Step 14

Go to Step 16

Does the Emergency 1st Switch parameter indicate
OFF when the switch is N?

—

Go to Step 15

Go to Step 19

Does the Emergency N Switch parameter indicate
ON when the switch is N?

—

Go to Intermittent

Conditions

Go to Step 21

1. Turn OFF the ignition switch.
2. Disconnect the emergency shift switch

harness connector.

3. Turn ON the ignition, with the engine OFF.
4. Observe the Emergency 1st Switch parameter

with the Tech 2 while momentarily jumping 3-
amp fused jumper wire between the
emergency shift switch harness (pin 3 of N-18
connector) and a known good ground.

Does the Tech 2 indicate ON when the circuit is
jumpered and OFF when the circuit is not
jumpered?

—

Go to Step 17

Go to Step 18

Observe the Emergency 1st Switch parameter with
the Tech 2 while momentarily jumping 3-amp fused
jumper wire across the emergency shift switch
harness (pins 3 and 5 of N-18 connector).

Does the Tech 2 indicate ON when the circuit is
jumpered and OFF when the circuit is not
jumpered?

—

Go to Step 29

Go to Step 33

1. Test the emergency 1st position switch signal

circuit between the TCM (pin 14 of B-428
connector) and the emergency shift switch (pin
3 of N-18 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 36

Go to Step 30

1. Turn OFF the ignition.
2. Disconnect the switch harness connector.
3. Turn ON the ignition, with the engine OFF.
4. Observe the Emergency 1st Switch parameter

with the Tech 2.

Does the Emergency 1st Switch parameter indicate
OFF?

—

Go to Step 34

Go to Step 20

Step

Action

Value(s)

Yes

Transmission Control System (Smoother) 7A-189

1. Test the emergency 1st position switch circuit

between the TCM (pin 14 of B-429 connector)
and the emergency shift switch (pin 3 of N-18
connector) for a short to ground.

2. Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 36

Go to Step 35

1. Turn OFF the ignition switch.
2. Disconnect the emergency shift switch

harness connector.

3. Turn ON the ignition, with the engine OFF.
4. Observe the Emergency N Switch parameter

with the Tech 2 while momentarily jumping 3-
amp fused jumper wire between the
emergency shift switch harness (pin 2 of N-18
connector) and a known good ground.

Does the Tech 2 indicate ON when the circuit is
jumpered and OFF when the circuit is not
jumpered?

—

Go to Step 22

Go to Step 23

Observe the Emergency N Switch parameter with
the Tech 2 while momentarily jumping 3-amp fused
jumper wire across the emergency shift switch
harness (pins 2 and 5 of N-18 connector).

Does the Tech 2 indicate ON when the circuit is
jumpered and OFF when the circuit is not
jumpered?

—

Go to Step 29

Go to Step 33

1. Test the emergency N position switch signal

circuit between the TCM (pin 6 of B-428
connector) and the emergency shift switch (pin
2 of N-18 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 36

Go to Step 30

1. Turn ON the ignition switch, with the engine

OFF.

2. Observe the Emergency R Switch parameter

with the Tech 2.

Does the Emergency R Switch parameter indicate
ON when the switch is R?

—

Go to Step 25

Go to Step 26

Does the Emergency R Switch parameter indicate
OFF when the switch is N?

—

Go to Intermittent

Conditions

Go to Step 31

1. Turn OFF the ignition switch.
2. Disconnect the emergency shift switch

harness connector.

3. Turn ON the ignition, with the engine OFF.
4. Observe the Emergency R Switch parameter

with the Tech 2 while momentarily jumping 3-
amp fused jumper wire between the
emergency shift switch harness (pin 1 of N-18
connector) and a known good ground.

Does the Tech 2 indicate ON when the circuit is
jumpered and OFF when the circuit is not
jumpered?

—

Go to Step 27

Go to Step 28

Step

Action

Value(s)

Yes

7A-190 Transmission Control System (Smoother)

Observe the Emergency R Switch parameter with
the Tech 2 while momentarily jumping 3-amp fused
jumper wire across the emergency shift switch
harness (pins 1 and 5 of N-18 connector).

Does the Tech 2 indicate ON when the circuit is
jumpered and OFF when the circuit is not
jumpered?

—

Go to Step 29

Go to Step 33

1. Test the emergency R position switch signal

circuit between the TCM (pin 20 of B-428
connector) and the emergency shift switch (pin
1 of N-18 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 36

Go to Step 30

1. Turn OFF the ignition.

Inspect for an intermittent and for poor connections
at the harness connector of the emergency shift
switch (pins 1, 2, 3 and 5 of N-18 connector).

2. Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 36

Go to Step 34

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

connections on the emergency shift switch
signal circuit at the harness connector of the
TCM (pin 6, 14 and 20 of B-428 connector).

4. Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 36

Go to Step 35

1. Turn OFF the ignition.
2. Disconnect the switch harness connector.
3. Turn ON the ignition, with the engine OFF.
4. Observe the Emergency R Switch parameter

with the Tech 2.

Does the Emergency R Switch parameter indicate
OFF?

—

Go to Step 34

Go to Step 32

1. Test the emergency R position switch circuit

between the TCM (pin 20 of B-428 connector)
and the emergency shift switch (pin 1 of N-18
connector) for a short to ground.

2. Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 36

Go to Step 35

Repair the open circuit or high resistance on the
ground circuit of the emergency shift switch (pin 5 of
N-18 connector) and the chassis ground (B-1).

Did you complete the repair?

Go to Step 36

—

Replace emergency shift switch.

Did you complete the replacement?

—

Go to Step 36

—

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 36

—

Step

Action

Value(s)

Yes

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