DTC
{MlL indication*l
Temporary DTCDetection ltemPage
P1259 t22JVTEC System l\4alfunction(see Daqe 11-123)P1291 t20\Electrical Load Detector (ELD) Circuit Low Voltaqe(see Daqe l1-92)P1298 (20)Electrical Load Detector (ELD) Circuit Hiqh Voltaqe(see oaoe 11-93)P1361 (8)Camshaft Position (CMP) Sensor B (Top Dead Center(TDC) Sensor) Intermittent Sional InterruDtion
(see page 11-95)
P1362 (8)Camshaft Position (CMP) Sensor B (Top Dead Center(TDC) Sensor) No Siqnal
(see page 11-95)
P'r456 (90)P1456Evaporative Emissions (EVAP) Control System
Leakaqe (Fuel Tank Svstem)
(see page 11-175)
P14s7 (90)P1457Evaporative Emissions (EVAP) Control System
Leakaqe (EVAP Canister Svstem)
(see page 1'l-180)
P1505 (109)P1505Positive Crankcase Ventilation (PCV) Air Leakaqe(see oaqe 11-1681
P1519 (14)ldle Air Control (lAC) Valve Circuit Malfunction{see paqe 11-131)P1607 ( )Engine Control Module (ECM) Internal Circuit
Malfunction
(see page 1 1-96)
" : These DTCS are indicated by a blinking MIL when the SCS service signal line is jumped with the Honda PGM
Tester.
11-9
Fuel and Emissions Systems
Symptom Troubleshooting Index
When the vehicle has one of these symptoms, check the diagnostic trouble code (DTC) with the scan tool. lf there is no
DTC, do the diagnostic procedure for the symptom, in the sequence listed, until you find the cause.
SvmotomDiaqnostic procedureAlso check lor
Engine will not sta rt
(MlL works OK, no DTCS set)
1. Test the battery {see page 22-50).
2. Test the starter (see page 4-8).
3. Troubleshoot the fuel pump circult (see page 11
141).
Low compressron
No ignition spark
lntake air leaks
Locked up engine
Broken timing chain
Contaminated fuel
Engine will not start (MlL
comes on and stays on, or
never comes on at all, no
DTCS set)
Troubleshoot the l\4lL circuit (see page 1 '1-97).
Engine will not start
(immobilizer indicator stays
on or flashs)
Troubleshoot the immobilizer system (see page 22-165).
Hard starting(MlL works OK, no DTCS set)
1. Testthe battery (see page 22-50).
2. Checkthe fuel pressure (see page 11-145).
Low compression
Intake air leaks
Contaminated fuel
Cold fast idle too low(MlL works OK. no DTCS set)
1. Do the ECM idle learn procedure (see page 11-139).
2. Checkthe idle sDeed (see paqe 11-138).
Cold fast idle too high
(MlL works OK, no DTCS set)
Do the ECI\4 idle learn procedure (see page 1 1- 139).
Checkthe idle speed {see page 11-138).
Inspect/adjust the throttle cable (see page 1 '1-'163).
Inspect and test the throttle body {see page 1 1-160}.
']
2.
3.
ldle speed fluctuates
(MlL works OK, no DTCS set)
1. Dothe ECM idle learn procedure (see page 11-'139).
2. Check the idle speed (see page 11-138).
3, Inspecvadjust th e throttle cable (see page 11''163).
4. Insoect and test the throttle bodv (see paqe 11- 160)
Intake air leaks
After warming up, idle speed
is below specifications with
no load
{MlL works OK, no DTCS set)
1. Do the ECIVI idle learn procedure (see page 1 1- 139).
2. Troubleshootthe alternator FR signal circuit (see
page 11-'134).
3. InsDect and test the throttle bodv {see paqe 1 1-160).
Vacuum hose clogged/
cracked/poor
connectron
After warming up, idle speed
is above specifications with
no toao(MlL works OK. no DTCS set)
1. Do the ECM idle learn procedure {see page 1'j-139).
2. Troubleshoot the alternator FR signal circuit(see
page 11-134).
Low power
(MlL works OK, no DTCS set)
1. Check the fuel pressure(seepagell-145).
2. Inspect and test the th roftle body (see page 11-160).
3. Inspecvadjust the throttle cable (see page 11-'163).
Low compressron
Camshaft timing
problem
Engine oil levelprootem
Engine stalls(MlL works OK. no DTCS set)
1. Do the ECM idle learn procedure (see page 1'l'139).
2. Check the fuel pressure{seepagell-145).
3. Check the idle speed (see page I 1-138).
4. Troubleshootthe brake pedal position switch signal
circuit (see paqe 11-137).
lntake air leaks
Faulty harness and
sensor connections
\
\-
11-10
\-
SymptomDiagnostic procedureAlso check torDifficult to refuel(MlL works OK. no DTCS set)
1. Testthefuel tank vapor control valve{seepage 1'l-
2. 1471.
Inspect the fuel tank vapor control signal tube
3. between the fuel pipe and the fuel tank vapor
control valve.
4. Inspect the fuel tank vapor vent tube between the
EVAP canister and the fuel tank vapor control valve.
Check the EVAP canister.
Malfunctioning gas
station filling nozzle.
Fuel overflows during
refueling(No DTCS set)
Replace the fuel tank vapor control valve (see page '1 1
189).
Malfunctioning gas
station filling nozzle.
11-11
Fuel and Emissions Systems
System Descriptions
Electronic Control System
The functions of the fuel and emlssion control systems are managed by the engine control module (ECM).
Fail-safe Function
When an abnormality occurs in the signal from a sensor, the ECI\4 ignores that signal and assumes a pre-programmed
value for that sensor that allows the enqine to continue to run.
Back-up Function
When an abnormality occurs in the ECM, the injectors are controlled by a back-up circuit independent of the system to
permit minimal driving.
Self-diagnosis
When an abnormality occurs in the signal from a sensor, the ECM supplies ground for the malfunction indicator lamp
{MlL) and stores the diagnostic trouble code {DTC) in erasable memory. When the ignition is first turned on, the EClvl
supplies ground to the l\4lL for 15 to 20 seconds to check the M lL bulb condition.
Two Driving Cycle Detection Method
To prevent false indications, the "two driving cycle detection method" is used for some self-diagnostic functions.
When an abnormality occurs, the ECM stores it in its memory. When the same abnormality recurs afterthe ignition
switch is turned OFF and ON (ll) again, the ECM turns on the MlL.
\
11-12
\.
\{
ECM Data
You can retrieve data from the ECI\4 by connecting the OBD ll scan tool or the Honda PGM Tester to the data link
connector (DLC). The items listed in the table below conform to SAE recommended practice. The Honda PGM Tester
also reads data beyond that recommended by SAE to help you find the causes of intermittent problems.
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 in the neutral position,
and the A,/C and all
Diagnostic
Trouble Code(DTC}
lf the ECM delects a problem, it will store it as a code
consisting of one letter and four numbers. Depending on
the problem, an SAE-defined code (Poxxx) or a Honda,
defined code {P1xxx) will be output to the tester.
The ECI\4 computes engine speed from the signals sent
from the crankshaft position (CKP) sensor. This data is
used for determining the time and amount of injected fuel.
detected, there is no
ourpul.
lf no problem is YES
Nearly the same as
tachometer indication
At idle speed;
The ECM converts pulse signals from the vehicle speed
sensor (VSS).Nearly the same as
speedometer
indication
Manifold
Absolute
Pressure(MAP)
The absolute pressure caused in the intake manifold by
engine load and speed.
With engine stopped: YES
Nearly the same as
almospnenc pressure.
At idle speed: about
20 4'1 kPa(150 310 mmHg,
6- 12 in.Hq).0.7 1.3 V
The ECT sensor converts coolant temperature into voltage
and signals the ECM. The sensor is a thermistor whose
internal resistance changes with coolant tempetature. The
ECM 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 116 2'12"F
100'c).0.5-0.8 v
Air Fuel Ratio The A,/F sensor detects the oxygen content in the exha ust 0.0 - 1 .25 V(Ay'F) Sensor. gas and sends voltage signals to the Eclvl, Basedonthese 8.0 11.0mA(PGM(Sensor 1) signals, the ECM controls the airlfuel ratio. When the I Tester)
oxygen content is high (that is, when the ratio is leaner At idle speed:
than the stoichiometric ratio), the voltage signal is Iower. about 0.1 0.9 V
When the oxygen content is low (that is, when the ralio is
richer than the stoichiometric ratio). the voltage signal is
higher. The A'lF sensor signals are electrical current that
are indicated as voltaqe on the
The HO2S detects the oxygen content in the exhaust gas
and sends voltage signals to the ECM. Based on these
signals, the ECM controls the airlfuel 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
Secondary
Heated
Oxygen
Sensor(Secondary
H02S,
Sensor2)
0.0 1.25 V NO
At idle speed:
about 0.1 0.9 V
(cont'd)
11-13
Fuel and Emissions Systems
System Descriptions (cont'dl
ECM lnputs and Outputs at Connector E (31P}
L
u
1iMoFPR
2sr-{]zs3LG34SG3
6$1025HTC
1M RLY
8AFSHTCR
I
14FTP15ELD
16EPSLD
18ACC20Z/VBS21VSV
22BKSW23K-LINE24SEFMJ26NEP
21rMoCD
29scs30WEN31MIL
Wire side of female terminals
NOTE: Standard battery voltage is '12 V.
TerminalnumberWire colorferminal nameDescription Signal
GRNI/ELIMO FPR (IMMOBILIZERFLJEL PUMP RELAYIDrives PGM Fl main relay 20Vfor2 seconds after turning ignition switch ON{ll). then batterv voltaoe2WHT/REDSHO2S (SECONDARYHEATED OXYGEN SENSOR(SECONDARY HO2S),SENSOR 2r
Detects secondary HO2S{sensor 2) signalWith throttle Jully opened from idle with fullywarmed up engine: above 0.6VWith throttle quickly closed: below 0.4 V
3BRN/YELLG3 (LOGIC GROUND)cround forthe ECM/PCMcontrolcircuitLess than 1.0 V at all times
4PNKSG3 {SENSOR GBOUND)Sensor oroundLess than 1.0 V at all times5YEUELUVCC3 {SENSOR VOLTAGE)Provides sensor voltageWith ignition switch ON (ll): about 5 VWith ionition switch OFF: about 0 V6BLKATr'HTSO25HTC (SECONDARYHEATED OXYGEN SENSOR(SECONDARY H02S)HEATER CONTROL)
Drives secondary HO2SheaterWith ignition switch ON (ll): baftery voltageWilh fullv warmed up engine running: dul,controlled
1REDA/ELMRLY (PGM.FI MAINRELAY}Drives PGM-Flmain relay 1Power source forthe DTCWith ignition switch ON (ll): about 0 VWith ignition switch OFF: battery voltage
IORNAFSHTCR {AIR FUEL BATIO(Iy'F)SENSOR HEATERCONTROL RELAY)
Drives air fuel ratio sensorheater relayWith ignition swirch ON {ll): 0 V
IYEUBLKIGl (IGNITION SIGNAL)Detecrs ignition signalWith ignition switch ON (ll): battery voltageWith iqnition switch OFF: about 0 V't4LT GRNFIP lFUEL TANKPRESSURE (FTP) SENSOR)Detects FTP sensor signalWith ignition switch ON (ll) and fuel fill cap open:about 2.5 VGRN/REDELD (ELECTRICAL LOADDETECTOF)Detects ELD signalWith ignition swjtch ON itt):aOoutO.t V l-gV(deDendino on electrical load)LT GRN/8LKEPSLD (ELECIRICALPOWEB STEEBING LOADDETECT)
Detects Power steering loadsrgnalAt idle with steering wheel in straight aheadposition: about 0 VAt idle with steering wheelatfull lock: momentary
'18REDACC (Ay'C CLUTCH RELAY)Drives P,/C clutch relayWith compressor ON: about 0 VWith comoressor OFF: batterv voltaoe
11-22
\-
lgnition Timing Control
The ECM contains the memory for basic ignition timing
at various engine speeds and manifold absolute
pressure. lt also adjusts the timing according to engine
coolant temperature.
Iniector Timing and Duration
The ECM contains the memory for basic discharge
duration at various engine speeds and manifold
pressures. The basic discharge duration, after being
read out from the memory, is further modified by
signals sent from various sensors to obtain the final
discharge duration.
By monitoring long term fuel trim, the ECM detects long
term malfunctions in the fuel system and sets a
Diagnostic Trouble Code {DTC).
Intake Air Temperature (lAT) Sensor
The IAT sensor is a temperature dependent resistor
{thermistor). The resistance of the thermistor decreases
as the intake air temDerature increases.
Knock Sensor
The knock control system adjusts the ignition timing to
minimize knock.
PIEZOCERAMIC
Malfunction Indicator Lamp lMlLl Indication {ln relation
to Readiness Codes)
The vehicle has certain "readiness codes" that are part
of the on-board diagnostics for the emissions systems.
lf the vehicle's baftery has been disconnected or gone
dead. if the DTCS have been cleared, or if the ECM has
been reset. these codes are set to incomplete. In some
states, part of the emissions testing is to make sure
these codes are set to comDlete. lf all of them are not
set to complete, the vehicle may fail the test and the
test cannot be finished.
To check if the readiness codes are set to complete,
turn the ignition switch ON (ll). but do not start the
engine.TheMILwill comeonforlS 20seconds. lf it
then goes off, the readiness codes are set to complete,
lf it blinks severaltimes, one or more readiness codes
are not set to comolete. To set each code, drive the
vehicle or run the engine as described in the
procedures to set them in this section (see page 1 1-46).
Manifold Absolute Pressure {MAP) Senso]
The MAP sensor converts manifold absolute pressure
into electrical signals to the ECM.
SENSOR UNIT
(cont'd)
11-27
Fuel and Emissions Systems
How to Set Readiness Codes
Malfunction lndicator Lamp (MlL) Indication
(ln relation to Readiness Codesl
The vehicle has certain "readiness codes" that are part
of the on-board diagnostics for the emissions systems.
lf the vehicle's battery has been disconnected or gone
dead, if the DTCS have been cleared, or if the ECM has
been reset, these codes are set to incomplete. In some
states, part of the emission testing is to make su re these
codes are set to complete. lf all of them are not set to
complete, the vehicle may fail the emission test, or the
test cannot be finished.
To check ifthe readiness codes are complete, turn the
ignition switch ON (ll), but do not start the engine. The
MIL will come on for 15 20 seconds. lf it then goes off,
the readiness codes are complete. lf it blinks several
times, one or more readiness codes are not complete.
To set readlness codes from incomplete to complete.
do the procedure for the appropriate code.
11-46
L
Catalytic Converter Monitor and Readiness
Code
NOTE:. Do not turn the ignition switch off during the
procedure.
. All readiness codes are cleared when the battery is
disconnected or when the ECM is cleared with the
OBD ll scan tool or Honda PG lvl Tester.. Low ambient temperatures or excessive slop-and-go
traffic may increase the drive time needed to switch
the readiness code from incomplete to complete.' The readiness code will not switch to com Dlete until
all the enable criteria are met.. lf a fault in the secondary HO2S system caused the
MIL to come on. the readiness code cannot be set to
comDlete until vou correct the fault.
Enable Criteria. ECT at 158"F (70'C) or higher.. Intake air temperature (lAT) at 20"F (-7'C) or higher.. Vehicle speed is steady, and vehicle speed sensor
(VSS) reads more then 25 mph (13km/h).
Procedure
1. Connect the scan tool to the vehicle's data link \
connector (DLCi, and bring up the tool's generic \"
OBD ll mode.
Start the engine.
Test-drive the vehicle under stop-and-go conditions
with short periods of steady cruise. After about
5 miles (3 km), the readiness code should switch
from incomplete to complete.
lf the readiness code is still set to incomplete, check
for a temporary DTC. lf there is no DTC, one or
more of the enable crlteria were probably not met;
2.
3.