Isuzu Trooper (1998-2002 year). Manual - part 433

6E–102

6VE1 3.5 ENGINE DRIVEABILITY AND EMISSIONS

Engine Cranks But Will Not Run

  (Cont'd)

Step

No

Yes

Value(s)

Action

31

1. At the injector (male) side of the gray connector

mentioned in step 25, connect an ohmmeter
between the ignition pin and one of the driver circuit
pins.

2. Check for continuity in the circuit.
3. Repeat for each injector circuit. The readings

should be approximately equal to the specified
value for injector resistance.

Was a problem found?

12.5 

W

Verify repair

Go to 

Step 8

32

Repair the ignition feed circuit.

Is the action complete?

—

Verify repair

—

33

Replace the PCM.

IMPORTANT: The replacement PCM must be
programmed.

Refer to 

ON-Vehicle Service in Power 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

—

34

1. Raise the vehicle and disconnect the CKP sensor

harness.

2. Ignition “ON”.
3. With a test light to ground, probe the harness

ignition feed terminal.

Did the light illuminate?

—

Go to 

Step 36

Go to 

Step 35

35

Check the ignition feed wire between the sensor and
the PCM for a short to ground or open circuit.

Is the action complete?

—

Verify repair

—

36

1. Ignition “ON”.
2. At the CKP harness connector, connect a test light

between the ignition and ground terminals.

Did the light illuminate?

—

Go to 

Step 38

Go to 

Step 37

37

Check the sensor ground circuit for an open or short to
voltage.

Is the action complete?

—

Verify repair

—

38

Check the signal circuit between the sensor and the
PCM for a short to ground, short to voltage, or an open.

Was a problem found?

—

Verify repair

Go to 

Step 39

39

Replace the CKP position sensor.

Is the action complete?

—

Verify repair

Go to 

Step 33

6E–103

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Fuel System Electrical Test

D06R200100

6E–104

6VE1 3.5 ENGINE DRIVEABILITY AND EMISSIONS

Circuit Description

When the ignition switch is first turned “ON”, the
powertrain control module (PCM) energizes the fuel
pump relay which applies power to the in-tank fuel pump.
The fuel pump relay will remain “ON” as long as the
engine is running or cranking and the PCM is receiving
58X crankshaft position pulses.  If no 58X crankshaft
position pulses are present, the PCM de-energizes the
fuel pump relay within 2 seconds after the ignition is
turned “ON” or the engine is stopped.
The fuel pump delivers fuel to the fuel rail and injectors,
then to the fuel pressure regulator.  The fuel pressure
regulator controls fuel pressure by allowing excess fuel to
be returned to the fuel tank.  With the engine stopped and
ignition “ON”, the fuel pump can be turned “ON” by using a
command by the Tech 2.

Diagnostic Aids

An intermittent may be caused by a poor connection,
rubbed-through wire insulation, or a wire broken inside
the insulation.  Check for the following items:

D

Poor connection or damaged harness – Inspect the
PCM harness and connectors for improper mating,
broken locks, improperly formed or damaged
terminals, poor terminal-to-wire connection, and
damaged harness.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. If the fuel pump is operating but incorrect pressure is

noted, the fuel pump wiring is OK and the “Fuel
System Pressure Test” chart should be used for
diagnosis.

CAUTION: To reduce the risk of fire and personal
injury:

D

It is necessary to relieve fuel system pressure
before connecting a fuel pressure gauge.  Refer to
Fuel Pressure Relief Procedure, below.

D

A small amount of fuel may be released when
disconnecting the fuel lines.  Cover fuel line
fittings with a shop towel before disconnecting, to
catch any fuel that may leak out.  Place the towel in
an approved container when the procedure is
completed.

Fuel Pressure Relief Procedure

1. Remove the fuel cap.
2. Remove the fuel pump relay from the underhood

relay center.

3. Start the engine and allow it to stall.
4. Crank the engine for an additional 3 seconds.

Fuel Gauge Installation

1. Remove the shoulder fitting cap.
2. Install fuel gauge J 34730-1 to the fuel feed line

located in front of and above the right side valve train
cover .

3. Reinstall the fuel pump relay.

6E–105

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Fuel System Electrical Test

 

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. Read the “Caution” above.
2. Relieve the fuel system pressure and install the fuel

pump pressure gauge to the test fitting.

3. Ignition ON, Engine is Off.
4. Use a Tech 2 to command the fuel pump “ON”.

(Refer to the Miscellaneous Test.)

Is there an immediate pressure build-up which
indicates the pump is running?

—

Go to 

Step 3

Go to 

Step 4

3

1. Verify that the pump is not running by removing the

fuel filler cap and listening.

2. Command the pump “ON” with the Tech 2.

Did the pump turn “OFF” after 2 seconds?

—

Test

completed

Go to 

Step 12

4

1. Ignition “OFF”.
2. Remove the fuel pump relay.
3. Using a test light connected to ground, probe the

battery feed to the relay.

Did the light illuminate?

—

Go to 

Step 6

Go to 

Step 5

5

Repair short or open battery feed to fuel pump relay.

Is the action complete?

—

Verify repair

—

6

1. Connect a test light between the two wires that

connect to the fuel pump relay pull-in coil.

2. Ignition “ON”.

Did the test light illuminate for 2 seconds and then turn
off?

—

Go to 

Step 12

Go to 

Step 7

7

1. With a test light connected to battery (–), probe the

fuel pump relay connector at the wire which runs
from the relay pull-in coil to the PCM.

2. Ignition “ON”.

Did the test light illuminate for 2 seconds and then turn
off?

—

Go to 

Step 8

Go to 

Step 9

8

Locate and repair open in the fuel pump relay ground
circuit.

Is the action complete?

—

Verify repair

—

9

Check for short or open between the PCM and the fuel
pump relay.

Was a problem found?

—

Verify repair

Go to 

Step 10

10

1. Check the fuel pump relay circuit for a poor terminal

connection at the PCM.

2. If a problem is found, replace terminal as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 11