Content .. 796 797 798 799 ..

Opel Frontera UE. Manual - part 798

6E1–75

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

Fuel System Electrical Test

(Cont'd)

Step

Yes

Value(s)

Action

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

Was a problem found?

—

Verify repair

Go to Step 10

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

connection at the ECM.

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

Was a problem found?

—

Verify repair

Go to Step 11

Replace the ECM.

Is the action complete?

—

Verify repair

—

1. Reconnect the fuel pump relay.
2. Disconnect the fuel pump electrical connector at the

fuel tank.

3. Using a test light connected to ground, probe the

fuel pump feed wire (harness side).

4. Command the fuel pump ON with a Tech 2.

Did the light illuminate for 2 seconds?

—

Go to Step 15

Go to Step 13

1. Honk the horn to verify that the horn relay is

functioning.

2. Substitute the horn relay for the fuel pump relay.
3. Leave the test light connected as in step 12.
4. Command the fuel pump ON with the Tech 2.

Did the test light illuminate for 2 seconds when the fuel
pump was commanded ON?

—

Go to Step 17

Go to Step 14

1. Re–connect the horn relay in its proper location.
2. Check for a short circuit, blown fuse or open circuit

between the relay and the fuel tank.

Is the action complete?

—

Verify repair

—

1. With the fuel pump electrical connector at the fuel

tank disconnected, connect a test light between the
feed wire and the ground wire (harness side).

2. Command the fuel pump ON with a Tech 2.

Did the test light illuminate for 2 seconds?

—

Go to Step 18

Go to Step 16

Repair the open circuit in the fuel pump ground wire.

Is the action complete?

—

Verify repair

—

1. Re–connect the horn relay in its proper location.
2. Replace the fuel pump relay.

Is the action complete?

—

Verify repair

—

Replace the fuel pump.

Is the action complete?

—

Verify repair

—

6E1–76

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

FUEL SYSTEM DIAGNOSIS

D06RX111

Circuit Description

When the ignition switch is turned ON, the engine control
module (ECM) will turn ON the in–tank fuel pump. The
in–tank fuel pump will remain ON as long as the engine is
cranking or running and the ECM is receiving 58X
crankshaft position pulses. If there are no 58X crankshaft
position pulses, the ECM will turn the in–tank fuel pump
OFF 2 seconds after the ignition switch is turned ON or 2
seconds after the engine stops running.
The in–tank fuel pump is an electric pump within an
integral reservoir. The in–tank fuel pump supplies fuel
through an in–line fuel filter to the fuel rail assembly. The
fuel pump is designed to provide fuel at a pressure above
the pressure needed by the fuel injectors. A fuel pressure
regulator, attached to the fuel rail, keeps the fuel available
to the fuel injectors at a regulated pressure. Unused fuel is
returned to the fuel tank by a separate fuel return line.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart:
2. Connect the fuel pressure gauge to the fuel feed

line as shown in the fuel system illustration. Wrap a
shop towel around the fuel pressure connection in
order to absorb any fuel leakage that may occur
when installing the fuel pressure gauge. With the
ignition switch ON and the fuel pump running, the
fuel pressure indicated by the fuel pressure gauge
should be 283–376 kPa (41–55 psi). This pressure
is controlled by the amount of pressure the spring
inside the fuel pressure regulator can provide.

3. A fuel system that cannot maintain a constant fuel

pressure has a leak in one or more of the following
areas:

The fuel pump check valve.

The fuel pump flex line.

6E1–77

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

The valve or valve seat within the fuel pressure
regulator.

The fuel injector(s)

4. Fuel pressure that drops off during acceleration,

cruise, or hard cornering may case a lean condition.
A lean condition can cause a loss of power, surging,
or misfire. A lean condition can be diagnosed using
a Tech 2. If an extremely lean condition occurs, the
oxygen sensor(s) will stop toggling. The oxygen
sensor output voltage(s) will drop below 500 mV.
Also, the fuel injector pulse width will increase.

IMPORTANT:

Make sure the fuel system is not

operating in the ”Fuel Cut–Off Mode.”

When the engine is at idle, the manifold pressure is
low (high vacuum). This low pressure (high vacuum)
is applied to the fuel pressure regulator diaphragm.
The low pressure (high vacuum) will offset the
pressure being applied to the fuel pressure regulator
diaphragm by the spring inside the fuel pressure
regulator. When this happens, the result is lower fuel
pressure. The fuel pressure at idle will vary slightly as
the barometric pressure changes, but the fuel
pressure at idle should always be less than the fuel
pressure noted in step 2 with the engine OFF.

16. Check the spark plug associated with a particular

fuel injector for fouling or saturation in order to
determine if that particular fuel injector is leaking. If
checking the spark plug associated with a particular
fuel injector for fouling or saturation does not
determine that a particular fuel injector is leaking,
use the following procedure:

Remove the fuel rail, but leave the fuel lines and
injectors connected to the fuel rail. Refer to Fuel Rail
Assembly in On–Vehicle Service.

Lift the fuel rail just enough to leave the fuel injector
nozzles in the fuel injector ports.

CAUTION: In order to reduce the risk of fire and
personal injury that may result from fuel spraying on
the engine, verify that the fuel rail is positioned over
the fuel injector ports and verify that the fuel injector
retaining clips are intact.

Pressurize the fuel system by connecting a 10 amp
fused jumper between B+ and the fuel pump relay
connector.

Visually and physically inspect the fuel injector
nozzles for leaks.

17. A rich condition may result from the fuel pressure

being above 376 kPa (55 psi). A rich condition may
cause a DTC P0132 or a DTC P0172 to set.
Driveability conditions associated with rich
conditions can include hard starting (followed by
black smoke) and a strong sulfur smell in the
exhaust.

20. This test determines if the high fuel pressure is due

to a restricted fuel return line or if the high fuel
pressure is due to a faulty fuel pressure regulator.

21. A lean condition may result from fuel pressure

below 333 kPa (48 psi). A lean condition may cause
a DTC P0131 or a DTC P0171 to set. Driveability
conditions associated with lean conditions can
include hard starting (when the engine is cold),
hesitation, poor driveability, lack of power, surging,
and misfiring.

22. Restricting the fuel return line causes the fuel

pressure to rise above the regulated fuel pressure.
Command the fuel pump ON with the Tech 2. The
fuel pressure should rise above 376 kPa (55 psi) as
the fuel return line becomes partially closed.

NOTE: Do not allow the fuel pressure to exceed 414 kPa
(60 psi). Fuel pressure in excess of 414 kPa (60 psi) may
damage the fuel pressure regulator.

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

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

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 5–8840–0378–0 to the fuel feed line

located on the upper right side of the engine near the
EGR valve.

3. Reinstall the fuel pump relay.

6E1–78

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

Fuel System Diagnosis

Step

Action

Value(s)

Yes

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

—

Go to Step 2

Go to OBD

System

Check

1. Turn the ignition OFF.
2. Turn the air conditioning system OFF.
3. Relieve fuel system pressure and install the fuel

pressure gauge.

4. Turn the ignition ON.

NOTE: The fuel pump will run for approximately 2
seconds. Use the Tech 2 to command the fuel pump
ON.

5. Observe the fuel pressure indicated by the fuel

pressure gauge with the fuel pump running.

Is the fuel pressure within the specified limits?

283–376 kPa

(41–55 psi)

Go to Step 3

Go to Step 17

NOTE: The fuel pressure will drop when the fuel pump
stops running, then it should stabilize and remain
constant.

Does the fuel pressure indicated by the fuel pressure
gauge remain constant?

—

Go to Step 4

Go to Step 12

1. When the vehicle is at normal operating

temperature, turn the ignition ON to build fuel
pressure and observe the measurement on the
gauge.

2. Start the engine and observe the fuel pressure

gauge.

Did the reading drop by the amount specified after the
engine was started?

21–105 kPa

(3–15 psi)

Go to Step 5

Go to Step 9

Is fuel pressure dropping off during acceleration,
cruise, or hard cornering?

—

Go to Step 6

Check for

improper fuel

Visually and physically inspect the following items for a
restriction:

The in–pipe fuel filter.

The fuel feed line.

Was a restrication found?

—

Verify repair

Go to Step 7

Remove the fuel tank and visually and physically
inspect the following items:

The fuel pump strainer for a restriction.

The fuel line for a leak.

Verify that the correct fuel pump is in the vehicle.

Was a problem found in any of these areas?

—

Verify repair

Go to Step 8

Replace the fuel pump.

Is the action complete?

—

Verify repair

—

1. Disconnect the vacuum hose from the fuel pressure

regulator.

2. With the engine idling, apply 12–14 inches of

vacuum to the fuel pressure regulator.

Does the fuel pressure indicated by the fuel pressure
gauge drop by the amount specified?

21–105 kPa

(3–15 psi)

Go to Step 10

Go to Step 11

Content .. 796 797 798 799 ..