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Isuzu Trooper (2000 year). Manual - part 305

6E–349

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0462– Fuel Level Sensor Circuit –Low Voltage

Step

Action

Value(s)

Yes

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to

Step 2

Go to

OBD

System

Check

1. Disconnected the fuel level sensor harness from its

connector at the fuel tank.

2. Ignition “ON,” engine “OFF.”
3. Using a DVM, measure the voltage between the

sensor harness positive and ground wires.

Is the voltage approximately equal to the specified
value?

5 V

Go to

Step 6

Go to

Step 3

1. Ignition “ON,” engine “OFF.”
2. With a DVM, backprobe the PCM connector at the

terminal which supplies 5 volts to the fuel level
sensor.

Is the voltage approximately equal to the specified
value?

5 V

Go to

Step 4

Go to

Step 9

1. Ignition “ON,” engine “OFF.”
2. Fuel level sensor disconnected from wiring

harness.

3. With a DVM, probe the 5-volt supply wire at the

sensor harness.

Is the voltage approximately equal to the value
measured in Step 4?

—

Go to

Step 5

Go to

Step 9

Check for open or high resistance connection in the
ground wire between the PCM and the fuel level
sensor.

Is the action complete?

—

Verify repair

—

Remove the fuel level sensor and check the following:

Does the arm move freely?

Are the wires open or intermittently open when
wiggled?

Do the resistance values match the specification
chart?

Was a problem found?

—

Go to

Step 7

Go to

Step 9

Replace the fuel level sensor.

Is the action complete?

—

Verify repair

—

Replace the PCM.

IMPORTANT: The replacement PCM must be
programmed. Refer to

On-Vehicle Service in

Powertrain Control Module and Sensors for
procedures. And also refer to latest Service Bulletin.

Check to see if the Latest software is released or not.
And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.

Is the action complete?

—

Verify repair

—

Short to ground between the PCM connector and the
fuel level sensor.

Is the action complete?

—

Verify repair

—

6E–350

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P0463 Fuel Level Sensor Circuit–High Voktage

060RY00163

Circuit Description

The fuel level sensor is an important input to powertrain
control module (PCM) for the enhanced evaporative
system diagnostic. Fuel level information is needed for
the PCM to know the volume of fuel in the tank. The fuel
level affects the rate of change in air pressure in the
evaporative system. Several of the enhanced
evaporative system diagnostic sub-tests are dependent
upon correct fuel level information. The diagnostic will not
run when the tank is greater than 85% or less than 15%,
full. Fuel level DTCs should be diagnosed before other
evaporative system DTCs because they can cause other
DTCs to be set.
The sending unit is a float in the fuel tank which moves a
wiper arm across a variable resistor. High fuel level
causes low resistance in the sending unit. This is
recognized by the PCM because the circuit operates at a
corresponding high voltage. When the circuit is
continuously shorted to a voltage source greater than a
specified value, or when the 5 volt signal is shorted to
ground, DTC P0463 is set.

Conditions for Setting the DTC

Fuel tank level “slosh test” is completed.

Fuel tank level “main test” is completed.

Fuel tank level data is valid.

Fuel tank level signal is greater than a specified value.

There are 100 test failures within a 200-test sample.

Action Taken When the DTC Sets

The PCM will not turn the malfunction indicator lamp
(MIL) “ON.”

The PCM will store conditions which were present
when the DTC set as Failure Records only. This
information will not be stored as Freeze Frame data.

Conditions for Clearing the DTC

The PCM will turn the MIL “OFF” after three
consecutive trips without a fault condition present. A
history DTC will be cleared if no fault conditions have
been detected for 40 warm-up cycles (engine coolant
temperature has risen 4

C (40

F) from the start-up

ECT, and ECT exceeds 71

C (160

F) during that

same ignition cycle) or the scan tool clearing function
has been used.

DTC P0463 can be cleared by using the scan tool
“Clear Info” function or by disconnecting the PCM
battery feed.

Diagnostic Aids

Damaged harness–Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
fuel level display on the scan tool while moving
connectors and wiring harnesses related to the sensor.
A change in the display will indicate the location of the
fault.

6E–351

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart.

2. The ETC and MAP sensors share a ground at PCM

terminal D9.

9. Equates the resistance values at various float

positions to the following fuel gauge readings:

DTC P0463– Fuel Level Sensor Circuit –High Voltage

Step

Action

Value(s)

Yes

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to

Step 2

Go to

OBD

System

Check

1. Disconnected the fuel level sensor harness from its

connector at the fuel tank.

2. Ignition “ON,” engine “OFF.”
3. Using a DVM, measure the voltage between the

sensor harness positive and ground wires.

Is the voltage approximately equal to the specified
value?

5 V

Go to

Step 8

Go to

Step 3

With the negative DVM lead connected to ground, use
the positive DVM lead to probe the sensor ground wire
with the harness still disconnected.

Does the DVM indicate a short to a voltage source?

—

Go to

Step 4

Go to

Step 5

Repair short to voltage between the sensor and the
PCM.

Is the repair complete?

—

Verify repair

—

With the negative DVM lead connected to ground, use
the positive DVM lead to probe the sensor positive wire
with the harness still disconnected.

Does the DVM indicate a voltage greater than the
specified value?

5 V

Go to

Step 4

Go to

Step 6

Open circuit between the PCM connector and the fuel
level sensor?

—

Verify repair

Go to

Step 7

Replace the PCM.

IMPORTANT: The replacement PCM must be
programmed. Refer to

On-Vehicle Service in

Powertrain Control Module and Sensors for
procedures. And also refer to latest Service Bulletin.

Check to see if the Latest software is released or not.
And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.

Is the action complete?

—

Verify repair

—

Remove the fuel level sensor and check the following:

Does the arm move freely?

Are the wire leads shorted together?

Do the resistance values match the specification
chart?

Was a problem found?

—

Go to

Step 9

Go to

Step 7

Replace the fuel level sensor.

Is the repair complete?

—

Verify repair

—

6E–352

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P0502 VSS Circuit Low Input

D06RY00070

Circuit Description

The vehicle speed sensor has a magnet rotated by the
transmission output shaft. Attached to the sensor is a hall
effect circuit the interacts with the magnetic field treated
by the rotating magnet. A 12-volt operating supply for the
speed sensor hall circuit is supplied from the meter fuse.
The VSS pulses to ground the 9-volt signal sent from the
powertrain control module (PCM) on the reference circuit.
The PCM interprets vehicle speed by the number of
pulses to ground per second on the reference circuit.

Conditions for Setting the DTC

Engine is running.

Engine speed is between 1800 RPM and 2500 RPM.

Throttle angle is between 10% and 40%.

Engine load is greater than 50 kPa.

PCM detects no VSS signal for 12.5 seconds over a
period of 15 seconds.

Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.

Conditions for Clearing the MIL/DTC

The PCM will turn the MIL “OFF” on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.

A history DTC P0502 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0502 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart.
10. To avoid backprobing the VSS and possibly

damaging a seal or terminal, the VSS output can be
tested at the point where the transmission harness
connects to the engine harness. Power and ground
are applied by jumpers to the VSS through the
connectors which are located to the rear of the air
cleaner assembly. The VSS signal is monitored
with a DVM as the rear driveshaft turns. The
wheels can be turned to rotate the driveshaft, or in
2-wheels-drive vehicles the driveshaft can be turned
directly.

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