Isuzu N-Series. Manual — part 902

Transmission Control System (Smoother) 7A-63

P0903

65

ON

Intermitten

tly ON

Clutch Actuator
Circuit High
Voltage

• The ignition switch

is ON.

• The ignition voltage

is more than 20
volts.

• The emergency

switch is OFF.

• The smoother main

relay is commanded
ON.

• The TCM detects a

high voltage condition
on the gearshift clutch
solenoid valve control
circuit when the
solenoid valve is
commanded OFF.

• Solenoid valve control

circuit is short to battery
or ignition voltage,
open circuit or high
resistance.

• Poor harness

connector connection.

• Faulty solenoid valve.
• Faulty TCM.

P0904

58

ON

OFF

Gate Select
Position Circuit

• The ignition switch

is ON.

• The ignition voltage

is more than 20
volts.

• The emergency

switch is OFF.

• The TCM detects that

the gear select position
sensor signal voltage is
less than 0.5 volts or
more than 4.5 volts.

• Sensor 5V reference

circuit is short to battery
or ignition voltage,
short to ground, short to
the low reference
circuit, open circuit or
high resistance.

• Sensor signal circuit is

short to battery or
ignition voltage, short to
any 5V reference
circuit, short to ground,
short to the low
reference circuit, open
circuit or high
resistance.

• Sensor low reference

circuit is open circuit or
high resistance.

• Poor harness

connector connection.

• Faulty sensor

installation condition.

• Faulty sensor.
• Faulty TCM.

P0906

52

ON

OFF

Selector Lever
Circuit

• The ignition switch

is ON.

• The ignition voltage

is more than 20
volts.

• The emergency

switch is OFF.

Either of following
condition is met:
• The TCM detects two

or more selector lever
N, D and R switch
signal is ON (pulled to
ground).

• The TCM detects two

or more selector lever
A, + and

− switch signal

is ON (pulled to ground)
when the selector lever
N, D or R switch signal
is ON (pulled to
ground).

• Switch signal circuit is

short to ground or short
each other.

• Faulty switch

installation condition.

• Faulty switch.
• Faulty selector lever.
• Faulty TCM.

P0907

51

OFF

OFF

Selector Lever
Circuit

• The ignition switch

is ON.

• The ignition voltage

is more than 20
volts.

• The emergency

switch is OFF.

• The TCM detects that

the selector lever N, D
and R switch signals
are OFF (open circuit)
at the same time.

• Switch signal circuit is

open circuit or high
resistance.

• Switch ground circuit is

open circuit or high
resistance.

• Poor harness

connector connection.

• Faulty switch

installation condition.

• Faulty switch.
• Faulty selector lever.
• Faulty TCM.

DTC

Flash
Code

W/L

Status

Buzzer

Status

DTC Name

Condition for Running

the DTC

Condition for Setting the

DTC

Possible Cause

7A-64 Transmission Control System (Smoother)

P0909

76

ON

OFF

Gate Select
Control Error

• DTCs P0718,

P0889, P0902,
P0903, P0904,
P0912, P0913,
P0914, P0973,
P0974, P0976 and
P0977 are not set.

• The ignition switch

is ON.

• The ignition voltage

is more than 20
volts.

• The emergency

switch is OFF.

• The gearshift

control box relay is
commanded ON.

• The selector lever is

other than N
position.

• The TCM detects the

gear select side lever
position does not reach
to a desired select
position continuously
when shifting to desired
gear.

• Faulty gear select

position sensor.

• Faulty gear select

position sensor
installation condition.

• Faulty select solenoid

valve.

• Faulty select solenoid

valve installation
condition.

• Faulty gear select lever

shaft.

• Faulty gearshift control

box.

• Select lever stuck.
• Incorrect vehicle

information
programming
(transmission type).

P0912

75

ON

Intermitten

tly ON

Select Solenoid
Valve Circuit
High Voltage

• DTC P0889 is not

set.

• The ignition switch

is ON.

• The ignition voltage

is more than 20
volts.

• The emergency

switch is OFF.

• The gearshift

control box relay is
commanded ON.

• The TCM detects a

high voltage condition
on the select solenoid
valve monitor circuit
when the solenoid
valve is commanded
OFF.

• Solenoid valve voltage

feed circuit is open
circuit or high
resistance.

• Solenoid valve control

circuit is short to battery
or ignition voltage,
open circuit or high
resistance.

• Solenoid valve ground

circuit is open circuit or
high resistance.

• Poor harness

connector connection.

• Faulty solenoid valve.
• Faulty TCM.

P0913

75

ON

Intermitten

tly ON

Select Solenoid
Valve Circuit Low
Voltage

• DTC P0889 is not

set.

• The ignition switch

is ON.

• The ignition voltage

is more than 20
volts.

• The emergency

switch is OFF.

• The gearshift

control box relay is
commanded ON.

• The TCM detects a low

voltage condition on the
select solenoid valve
monitor circuit when the
solenoid valve is
commanded ON.

• Solenoid valve control

circuit is short to
ground.

• Faulty solenoid valve.
• Faulty TCM.

DTC

Flash
Code

W/L

Status

Buzzer

Status

DTC Name

Condition for Running

the DTC

Condition for Setting the

DTC

Possible Cause

Transmission Control System (Smoother) 7A-65

P0914

57

ON

OFF

Gear Shift
Position Circuit

• The ignition switch

is ON.

• The ignition voltage

is more than 20
volts.

• The emergency

switch is OFF.

• The TCM detects that

the gear shift position
sensor signal voltage is
less than 0.5 volts or
more than 4.5 volts.

• Sensor 5V reference

circuit is short to battery
or ignition voltage,
short to ground, short to
the low reference
circuit, open circuit or
high resistance.

• Sensor signal circuit is

short to battery or
ignition voltage, short to
any 5V reference
circuit, short to ground,
short to the low
reference circuit, open
circuit or high
resistance.

• Sensor low reference

circuit is open circuit or
high resistance.

• Poor harness

connector connection.

• Faulty sensor

installation condition.

• Faulty sensor.
• Faulty TCM.

P0915

74

ON

OFF

Gear Shift
Position Control
Disengage Error

• DTCs P0718,

P0889, P0902,
P0903, P0904,
P0912, P0913,
P0914, P0973,
P0974, P0976 and
P0977 are not set.

• The ignition switch

is ON.

• The ignition voltage

is more than 20
volts.

• The emergency

switch is OFF.

• The gearshift

control box relay is
commanded ON.

• The selector lever is

other than N
position.

• The TCM detects the

gear shift side lever
position does not reach
to a desired shift
position and it keeping
a previously engaged
gear position
continuously when
shifting to desired gear.
This indicates that the
TCM detects gear stuck
at an engaged position.

• Faulty gear shift

position sensor.

• Faulty gear shift

position sensor
installation condition.

• Faulty 1-3-5 or 2-4-6-R

shift solenoid valve.

• Faulty 1-3-5- or 2-4-6-R

shift solenoid valve
installation condition.

• Faulty gear shift lever

shaft.

• Faulty gearshift control

box.

• Shift lever stuck.
• Faulty gearshift clutch

(stuck engage).

• Transmission stuck.

P0919

72

ON

OFF

Gear Shift
Position Engage
Error

• DTCs P0718,

P0889, P0902,
P0903, P0904,
P0912, P0913,
P0914, P0973,
P0974, P0976 and
P0977 are not set.

• The ignition switch

is ON.

• The ignition voltage

is more than 20
volts.

• The emergency

switch is OFF.

• The gearshift

control box relay is
commanded ON.

• The selector lever is

other than N
position.

• The TCM detects the

gear shift side lever
position does not reach
to a desired shift
position continuously
when shifting to desired
gear.

• Faulty gear shift

position sensor.

• Faulty gear shift

position sensor
installation condition.

• Faulty 1-3-5 or 2-4-6-R

shift solenoid valve.

• Faulty 1-3-5- or 2-4-6-R

shift solenoid valve
installation condition.

• Faulty gear shift lever

shaft.

• Faulty gearshift control

box.

• Shift lever stuck.
• Faulty gearshift clutch

(stuck engage).

• Transmission stuck.

DTC

Flash
Code

W/L

Status

Buzzer

Status

DTC Name

Condition for Running

the DTC

Condition for Setting the

DTC

Possible Cause

7A-66 Transmission Control System (Smoother)

P0973

71

ON

Intermitten

tly ON

2-4-6-R Shift
Solenoid Valve
Circuit High
Voltage

• DTC P0889 is not

set.

• The ignition switch

is ON.

• The ignition voltage

is more than 20
volts.

• The emergency

switch is OFF.

• The gearshift

control box relay is
commanded ON.

• The TCM detects a

high voltage condition
on the 2-4-6-R shift
solenoid valve monitor
circuit when the
solenoid valve is
commanded OFF.

• Solenoid valve voltage

feed circuit is open
circuit or high
resistance.

• Solenoid valve control

circuit is open circuit or
high resistance.

• Solenoid valve ground

circuit is open circuit or
high resistance.

• Poor harness

connector connection.

• Faulty solenoid valve.
• Faulty TCM.

P0974

71

ON

Intermitten

tly ON

2-4-6-R Shift
Solenoid Valve
Circuit Low
Voltage

• DTC P0889 is not

set.

• The ignition switch

is ON.

• The ignition voltage

is more than 20
volts.

• The emergency

switch is OFF.

• The gearshift

control box relay is
commanded ON.

• The TCM detects a low

voltage condition on the
2-4-6-R shift solenoid
valve monitor circuit
when the solenoid
valve is commanded
ON.

• Solenoid valve control

circuit is short to
ground.

• Faulty solenoid valve.
• Faulty TCM.

P0976

73

ON

Intermitten

tly ON

1-3-5 Shift
Solenoid Valve
Circuit High
Voltage

• DTC P0889 is not

set.

• The ignition switch

is ON.

• The ignition voltage

is more than 20
volts.

• The emergency

switch is OFF.

• The gearshift

control box relay is
commanded ON.

• The TCM detects a

high voltage condition
on the 1-3-5 shift
solenoid valve monitor
circuit when the
solenoid valve is
commanded OFF.

• Solenoid valve voltage

feed circuit is open
circuit or high
resistance.

• Solenoid valve control

circuit is short to battery
or ignition voltage,
open circuit or high
resistance.

• Solenoid valve ground

circuit is open circuit or
high resistance.

• Poor harness

connector connection.

• Faulty solenoid valve.
• Faulty TCM.

P0977

73

ON

Intermitten

tly ON

1-3-5 Shift
Solenoid Valve
Circuit Low
Voltage

• DTC P0889 is not

set.

• The ignition switch

is ON.

• The ignition voltage

is more than 20
volts.

• The emergency

switch is OFF.

• The gearshift

control box relay is
commanded ON.

• The TCM detects a low

voltage condition on the
1-3-5 shift solenoid
valve monitor circuit
when the solenoid
valve is commanded
ON.

• Solenoid valve control

circuit is short to
ground.

• Faulty solenoid valve.
• Faulty TCM.

DTC

Flash
Code

W/L

Status

Buzzer

Status

DTC Name

Condition for Running

the DTC

Condition for Setting the

DTC

Possible Cause