Content .. 76 77 78 79 ..

Acura RSX Honda Integra. Manual - part 78

Ｓ６Ｍ６ＡＺＨＡ２０３００００００００ＨＢＡＴ０１

2005-2006 Models

Symptom

Diagnostic procedure

Also check for

11-18

Fuel and Emissions Systems

Symptom Troubleshooting Index (cont’d)

When the vehicle has one of these symptoms, check for a diagnostic trouble code (DTC) with the HDS. If there is no
DTC, do the diagnostic procedure for the symptom, in the sequence listed, until you find the cause.

•

•
•
•

•

•
•

•

Engine will not start
(MIL works OK, no DTCs set)

1.
2.
3.
4.

Test the battery (see page 22-61).
Test the starter (see page 4-10).
Check the fuel pressure (see page 11-363).
Troubleshoot the fuel pump circuit (see page 11-356).

Low
compression
No ignition spark
Intake air leaks
Locked up
engine
Broken cam
chain
Contaminated
fuel

Engine will not start
(MIL comes on and stays on,
or never comes on at all, no
DTCs set)

Troubleshoot the MIL circuit (see page 11-260).

Engine will not start
(immobilizer indicator stays
on or flashes)

Troubleshoot the immobilizer system (see page 22-178).

Engine is hard to start
(MIL works OK, no DTCs set)

1.
2.
3.

Test the battery (see page 22-61).
Check the fuel pressure (see page 11-363).
Test the throttle body (see page 11-403).

Low
compression
Intake air leaks
Contaminated
fuel
Weak spark

Cold fast idle too low
(MIL works OK, no DTCs set)

1.
2.

Do the ECM/PCM idle learn procedure (see page 11-349).
Check the idle speed (see page 11-348).

Cold fast idle too high
(MIL works OK, no DTCs set)

1.
2.
3.
4.

Do the ECM/PCM idle learn procedure (see page 11-349).
Check the idle speed (see page 11-348).
Inspect/adjust the throttle cable (see page 11-408).
Test the throttle body (see page 11-403).

Idle speed fluctuates
(MIL works OK, no DTCs set)

1.
2.
3.
4.

Do the ECM/PCM idle learn procedure (see page 11-349).
Check the idle speed (see page 11-348).
Inspect/adjust the throttle cable (see page 11-408).
Test the throttle body (see page 11-403).

Intake vacuum
leaks

After warming up, idle speed
is below specification without
load
(MIL works OK, no DTCs set)

1.
2.

Troubleshoot the A/C signal circuit (see page 11-338).
Troubleshoot the alternator FR signal circuit (see page
11-341).
Test the throttle body (see page 11-403).

Vacuum hose
clogged/cracked/
poor connection

After warming up, idle speed
is above specification without
load
(MIL works OK, no DTCs set)

1.
2.
3.

4.
5.

Inspect/adjust the throttle cable (see page 11-408).
Troubleshoot the A/C signal circuit (see page 11-338).
Troubleshoot the alternator FR signal circuit (see page
11-341).
Test the throttle body (see page 11-403).
Inspect the TP sensor (see page 11-404).

Intake air leaks

05/06/27 17:31:13 61S6M040_110_0018

Symptom

Diagnostic procedure

Also check for

11-19

•

•
•

Low power
(MIL works OK, no DTCs set)

1.
2.
3.

Check the fuel pressure (see page 11-363).
Inspect/adjust the throttle cable (see page 11-408).
Test the throttle body (see page 11-403).

Low
compression
Incorrect
camshaft timing
Incorrect engine
oil level

Engine stalls
(MIL works OK, no DTCs set)

1.
2.
3.
4.

Do the ECM/PCM idle learn procedure (see page 11-349).
Check the fuel pressure (see page 11-363).
Check the idle speed (see page 11-348).
Troubleshoot the brake pedal position switch signal
circuit (see page 11-347).

Intake air leaks
Faulty harness
and sensor
connections

Difficult to refuel
(MIL works OK, no DTCs set)

Check the fuel vent tube between the EVAP canister and
the fuel tank.
Check the fuel tank vapor recirculation tube between
the fuel pipe and the fuel tank.
Replace the fuel tank (see page 11-378).

Malfunctioning gas
station filling
nozzle.

Fuel overflows during
refueling
(No DTCs set)

Replace the fuel tank (see page 11-378).

Malfunctioning gas
station filling
nozzle.

05/06/27 17:31:13 61S6M040_110_0019

−

−
−

−

Ｓ６Ｍ６Ａ００Ａ２０３００００００００ＣＡＡＴ００

ECM/PCM Data (2002-2004 Models)

Data

Description

Operating Value

Freeze Data

11-20

Fuel and Emissions Systems

System Description

You can retrieve data from the ECM/PCM by connecting a scan tool or the HDS to the data link connector (DLC). The
items listed in the table conform to SAE recommended practice. The HDS also reads data beyond that recommended
by SAE to help you find the causes of intermittent problems.

NOTE:

• The ‘‘operating values’’ listed are approximate and may vary depending on the environment and the individual

vehicle.

• Unless noted otherwise, ‘‘at idle speed’’ means idling with the engine completely warmed up, A/T in Park or neutral,

M/T in neutral position, and the A/C and all accessories turned off.

Diagnostic
Trouble Code
(DTC)

If the ECM/PCM detects a problem, it will store it as a code
consisting of one letter and four numbers. Depending on
the problem, an SAE-defined code (P0xxx, P2xxx) or a
Honda-defined code (P1xxx) will be output to a scan tool
or the HDS.

If no problem is
detected, there is no
output.

YES

Engine Speed

The ECM/PCM computes engine speed from the signals
sent from the Crankshaft Position (CKP) sensor. This data
is used for determining the timing and amount of injected
fuel.

Nearly the same as
tachometer indication
At idle speed: 650
50 rpm (700

50 rpm)

YES

Vehicle Speed

The ECM/PCM converts pulse signals from Vehicle Speed
Sensor (VSS).

Nearly the same as
speedometer
indication

YES

Manifold
Absolute
Pressure
(MAP)

The absolute pressure caused in the intake manifold by
engine load and speed.

With engine stopped:
Nearly the same as
atmospheric pressure.
At idle speed: about
20

41 kPa

12 in.Hg,

150

310 mmHg),

about 0.7

1.3 V

YES

Engine
Coolant
Temperature
(ECT)

The ECT sensor converts coolant temperature into voltage
and signals the ECM/PCM. The sensor is a thermistor
whose internal resistance changes with coolant
temperature. The ECM/PCM uses the voltage signals from
the ECT sensor to determine the amount of injected fuel.

With cold engine:
Same as ambient
temperature and IAT.
With engine warmed
up: about 176

212 °F

(80

100 °C), about

0.5

0.8 V

YES

Air Fuel Ratio
(A/F) Sensor,
(Sensor 1)

The A/F sensor detects the oxygen content in the exhaust
gas and sends voltage signals to the ECM/PCM. Based on
these signals, the ECM/PCM controls the air/fuel ratio.
When the oxygen content is high (that is, when the ratio is
leaner than the stoichiometric ratio), the voltage signal is
lower. When the oxygen content is low (that is, when the
ratio is richer than the stoichiometric ratio), the voltage
signal is higher. The A/F sensor signals are electrical
current that are indicated as voltage on a scan tool or the
HDS.

0.0

1.25 V

At idle speed:
about 0.1

0.9 V

1: K20A2 engine

05/06/27 17:31:13 61S6M040_110_0020

−

Data

Description

Operating Value

Freeze Data

11-21

Heated
Oxygen
Sensor (HO2S)
(Secondary,
Sensor 2)

The HO2S detects the oxygen content in the exhaust gas
and sends voltage signals to the ECM/PCM. Based on
these signals, the ECM/PCM controls the air/fuel ratio.
When the oxygen content is high (that is, when the ratio is
leaner than the stoichiometric ratio), the voltage signal is
lower. When the oxygen content is low (that is, when the
ratio is richer than the stoichiometric ratio), the voltage
signal is higher.

about 0.0

1.25 V

At idle speed:
about 0.1

0.9 V

Fuel System
Status

Fuel system status is indicated as ‘‘open’’ or ‘‘closed’’.
Closed: Based on the A/F Sensor output, the ECM/PCM
determines the air/fuel ratio and controls the amount of
injected fuel.
Open: Ignoring A/F Sensor output, the ECM/PCM refers to
signals from the Throttle Position (TP), Manifold Absolute
Pressure (MAP), Intake Air Temperature (IAT), Barometric
Pressure (BARO) and Engine Coolant Temperature (ECT)
sensors to control the amount of injected fuel.

At idle speed: closed

YES

Short Term
Fuel Trim

The air/fuel ratio correction coefficient for correcting the
amount of injected fuel when the Fuel System Status is
‘‘closed’’. When the ratio is leaner than the stoichiometric
ratio, the ECM/PCM increases short term fuel trim
gradually, and the amount of injected fuel increases. The
air/fuel ratio gradually gets richer, causing a lower
oxygen content in the exhaust gas. Consequently, the
short term fuel trim is lowered, and the ECM/PCM reduces
the amount of injected fuel.
This cycle keeps the air/fuel ratio close to the
stoichiometric ratio when in closed loop status.

0.7

1.5

YES

Long Term
Fuel Trim

Long term fuel trim is computed from short term fuel trim
and indicates changes occurring in the fuel supply system
over a long period.
If long term fuel trim is higher than 1.00, the amount of
injected fuel must be increased. If it is lower than 1.00, the
amount of injected fuel must be reduced.

0.8

1.2

YES

Intake Air
Temperature
(IAT)

The IAT sensor converts intake air temperature into
voltage and signals the ECM/PCM. When intake air
temperature is low, the internal resistance of the sensor
increases, and the voltage signal is higher.

With cold engine:
Same as ambient
temperature and ECT

YES

Throttle
Position

Based on the accelerator pedal position, the opening
angle of the throttle valve is indicated.

At idle speed:
about 10 %

YES

Ignition
Timing

Ignition timing is the ignition advance angle set by the
ECM/PCM. The ECM/PCM matches ignition timing to the
driving conditions.

At idle speed: 8 °

5 °

BTDC when the SCS
line is jumped with the
HDS

Calculated
Load Value
(CLV)

CLV is the engine load calculated from the MAP data.

At idle speed:
12

34 %

At 2,500 rpm without
load:
14

34 %

YES

(cont’d)

05/06/27 17:31:13 61S6M040_110_0021

Content .. 76 77 78 79 ..