Infiniti Q45. Manual - part 360

BASIC SERVICE PROCEDURE

EC-79

Touch “START” and wait 20 seconds.

Make sure that “CMPLT” is displayed on CONSULT-II screen. If
“CMPLT” is not displayed, Idle Air Volume Learning will not be
carried out successfully. In this case, find the cause of the inci-
dent by referring to the DIAGNOSTIC PROCEDURE below.

Rev up the engine two or three times and make sure that idle
speed and ignition timing are within the specifications.

Without CONSULT-II

NOTE:

●

It is better to count the time accurately with a clock.

●

It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit
has a malfunction.

Perform

EC-77, "Accelerator Pedal Released Position Learning"

Perform

EC-78, "Throttle Valve Closed Position Learning"

Start engine and warm it up to normal operating temperature.

Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.

Turn ignition switch OFF and wait at least 10 seconds.

Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.

Repeat the following procedure quickly five times within 5 seconds.

Fully depress the accelerator pedal.

Fully release the accelerator pedal.

Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stops
blinking and turned ON.

Fully release the accelerator pedal within 3 seconds after the MIL turned ON.

10. Start engine and let it idle.

11. Wait 20 seconds.

12. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the

specifications.

SEF454Y

ITEM

SPECIFICATION

Idle speed

650

50 rpm (in P or N position)

Ignition timing

BTDC (in P or N position)

MBIB0238E

SEC897C

EC-80

BASIC SERVICE PROCEDURE

13. If idle speed and ignition timing are not within the specification, Idle Air Volume Learning will not be carried

out successfully. In this case, find the cause of the incident by referring to the Diagnostic Procedure below.

DIAGNOSTIC PROCEDURE

If idle air volume learning cannot be performed successfully, proceed as follows:

Check that throttle valve is fully closed.

Check PCV valve operation.

Check that downstream of throttle valve is free from air leakage.

When the above three items check out OK, engine component parts and their installation condi-
tion are questionable. Check and eliminate the cause of the incident.
It is useful to perform

EC-135, "TROUBLE DIAGNOSIS - SPECIFICATION VALUE"

If any of the following conditions occur after the engine has started, eliminate the cause of the
incident and perform Idle Air Volume Learning all over again:

–

Engine stalls.

–

Erroneous idle.

Fuel Pressure Check

NBS001QY

FUEL PRESSURE RELEASE

With CONSULT-II

Turn ignition switch ON.

Perform “FUEL PRESSURE RELEASE” in “WORK SUPPORT”
mode with CONSULT-II.

Start engine.

After engine stalls, crank it two or three times to release all fuel
pressure.

Turn ignition switch OFF.

Without CONSULT-II

Remove fuel pump fuse located in fuse box.

Start engine.

After engine stalls, crank it two or three times to release all fuel
pressure.

Turn ignition switch OFF.

Reinstall fuel pump fuse after servicing fuel system.

FUEL PRESSURE CHECK

Before disconnecting fuel line, release fuel pressure from fuel line to eliminate danger.

NOTE:

●

Use Fuel Pressure Gauge Kit (J-44321) to check fuel pressure.

●

Prepare pans or saucers under the disconnected fuel line because the fuel may spill out. The fuel
pressure cannot be completely released because F50 models do not have fuel return system.

Release fuel pressure to zero. Refer to

EC-80, "FUEL PRESSURE RELEASE"

ITEM

SPECIFICATION

Idle speed

650

50 rpm (in P or N position)

Ignition timing

BTDC (in P or N position)

SEF214Y

PBIB0041E

BASIC SERVICE PROCEDURE

EC-81

Install the inline fuel quick disconnected fitting between fuel
damper and fuel tube.

Connect the fuel pressure test gauge (quick connector adapter
hose) to the inline fuel quick disconnected fitting.

Turn ignition switch ON and check for fuel leakage.

Start engine and check for fuel leakage.

Read the indication of fuel pressure gauge.

If result is unsatisfactory, go to next step.

Check the following.

●

Fuel hoses and fuel tubes for clogging

●

Fuel filter for clogging

●

Fuel pump

●

Fuel pressure regulator for clogging

If OK, replace fuel pressure regulator.
If NG, repair or replace.

PBIB2442E

At idling:

Approximately 350 kPa

(3.57 kg/cm

, 51 psi)

PBIB1243E

EC-82

TROUBLE DIAGNOSIS

PFP:00004

Trouble Diagnosis Introduction

NBS001QZ

INTRODUCTION

The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or other malfunctions with the engine.

It is much more difficult to diagnose an incident that occurs intermit-
tently rather than continuously. Most intermittent incidents are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.

A visual check only may not find the cause of the incidents. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the Work Flow on

EC-83

Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A Diagnostic Worksheet like the example
on

EC-87

should be used.

Start your diagnosis by looking for conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.

MEF036D

SEF233G

SEF234G

Content .. 358 359 360 361 ..