Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 329

6E–346

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) 

P0462 Fuel Level Sensor Circuit–Low Voltage

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 more 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. Low fuel level
causes high resistance in the sending unit, and this is
recognized by the PCM because the circuit operates at a
corresponding low voltage.  When the circuit is
continuously open or has a high resistance connection,
DTC P0462 is set.

Conditions for Setting the DTC

D

Fuel tank level “slosh test” is completed.

D

Fuel tank level “main test” is completed.

D

Fuel tank level data is valid.

D

Fuel tank level signal is less than a specified value.

D

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

Action Taken When the DTC Sets

D

The PCM will ON the MIL after second trip with
detected the fault.

D

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 DTC

D

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).

D

DTC P0462 can be cleared by using the scan tool
“Clear Info” function or by disconnecting the PCM
battery feed.

Diagnostic Aids

D

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–347

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart.
8. The following chart can be used to check the

sending unit:

6E–348

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0462– Fuel Level Sensor Circuit –Low Voltage

 

Step

Action

Value(s)

Yes

No

1

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

—

Go to 

Step 2

Go to 

OBD

System

Check

2

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

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

4

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

5

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

— 

6

Remove the fuel level sensor and check the following:

D

Does the arm move freely?

D

Are the wires open or intermittently open when
wiggled?

D

Do the resistance values match the specification
chart?

Was a problem found?

—

Go to 

Step 7

Go to 

Step 9

7

Replace the fuel level sensor.

Is the action complete?

—

Verify repair

—

8

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

—

9

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

Is the action complete?

—

Verify repair

—

6E–349

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) 

P0463 Fuel Level Sensor Circuit–High Voltage

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 more 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

D

Fuel tank level “slosh test” is completed.

D

Fuel tank level “main test” is completed.

D

Fuel tank level data is valid.

D

Fuel tank level signal is greater than a specified value.

D

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

Action Taken When the DTC Sets

D

The PCM will ON the MIL after second trip with
detected the fault.

D

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 DTC

D

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.

D

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