2003 HONDA CIVIC Throttle

DTC Troubleshooting Index
";These DTCs are indicated by a blinking malfunction indicator lamp (MlL)when the SCS service signal line isjumped with the Honda PGM Tester.
{cont'd)
11-7
DTC
{MlL indication*)
Temporary DTCDetection ltemNote
P0010 (56)Variable Valve Timing Control {VTC) Oil Control
Solenoid Valve Malfunction
{see page 1 1'1 18)
P0011 (56)P001 1Variable Valve Timing Control (WC) System
Malfunction
(see page 11- 1 19)
P0107 (3)Manifold Absolute Pressure (MAP) Sensor Circuit
Low Voltaqe
(see page 1'l-521
P0108 (3)Manifold Absolute Pressure (MAP) Sensor Circuit
Hiqh Voltaqe
(see page 11-53)
P0112 (10)Intake Air Temperature (lAT) Sensor Circuit Low
Voltaoe
(see page 11-55)
P01r3 (10)Intake Air Temperature (lAT) Sensor Circuit High
Voltaoe
(see page '11-56)
P0116 {86) P0116Englne Coolant Temperature (ECT) Sensor Range/
Performance Problem
{see page 11-57)
P0117 {6)Engine Coolant Temperature (ECT) Sensor Circuit
Low Voltaqe
(see page 11-58)
P0118 {6)Engine Coolant Temperature (ECT) Sensor Circuit
Hiqh Voltaqe
{see page 11-59)
P0122 t7\Throttle Position (TP) Sensor Circuit Low Voltaqe(see Daqe 11-60)P0123 {7)Throttle Posltion (TP) Sensor Circuit Hiqh Voltaoe(see paqe 11-62)
P0128 (87)P0128Coolinq SVStem Malfunction(see Daqe 11-64)
P0134 (41)Air Fuel Ratio (Ay'F) Sensor (Sensor 1) No Activity
Detected
(see page 11-65)
P0137 (63)P0137Secondary Heated Oxygen Sensor (Secondary HO2S)(Sensor 2) Circuit Low Voltaqe
(see page 11-65)
P0138 (63)P0138Secondary Heated Oxygen Sensor (Secondary HO2S)(Sensor 2) Circuit Hiqh Voltaqe
(see page 11-66)
P0139 (63)P0139Secondary Heated Oxygen Sensor (Secondary H02S)(Sensor 2) Slow ResDonse
(see page 11-67)
P0141 (65)Secondary Heated Oxygen Sensor (Secondary H02S)(Sensor 2) Heater Circuit Malfunction
(see page 11-68)
P0171 (45)PO\11Fuel Svstem Too Lean(see paqe 11-70)
PO112 l'45)PO\l2Fuel System Too Rich(see oaoe 11-70)
P0300 and any P0300 and any
of of
P0301 (71) P0301
PO302 (721 P0302
P0303 (73) P0303
P0304 (74) P0304
Random Misfire(see page 11-71)
P0301 (7'1) P0301No. 1 Cylnder Misfire{see page 11-72)
P0302 (721 P0302No. 2 Cvlnder Misfire{see paqe 1 1-72)
P0303 (73)P0303No. 3 Cvlnder Misfire(see oaqe 11-72)
P0304 {74)P0304No. 4 Cvlnder Misfire{see Daqe 1 1-72)

Fuel and Emissions Systems
Knock Sensor Circuit N4alfunction
Crankshaft Position (CKP) Sensor Intermittent(see page 11-78)
(see oaqe 11-121
PO4i{
TU45I
P0452
Camshaft Position (CMP) Sensor A Intermiftentisee page 11-121)
Yetrgb-le Velye TiTing _controlll/T!) Phqse Gsee oaoe 11-122
CqJalyst System Elficie-ncy Below Thresholdsee oaqe 1 1- 167
Fuel Tank Pressure (FTP) Sensor Range/Performance (seepagell 171)
Sensor Circuit Low V11-172
Fuel Tank Pressure (FTP) Sensor Circuit High V
Vehicle SDeed SensorCircuit Malf unction
Camshaft Position (CMP) Sensor A No
P0451 (91)
see Daqe 11-130)
(see page 1 1-81)
Refer to the l\4ultiplex
Control System
Troubleshooting {see
(see page 1 1-83)
(see paSe 1 1'83)
Barometric Pressure (BARO) Sensor Circuit High{see page 11-83)
P't 121
Pl122
P11f,.8
Throttle Position {TPi Sensor Signal Lower Than(see page 11-63)
-tsee page I r-oJ,
G;tp"s" 1 154)
(*" paSe 1 154)
P1122 ll J
ij1128 (5)
Throttle Position (TP) Sensor Signal Higher Than
Mani{old Absolute Pressure (l\,4AP} Sensor Signal
Loqer Tha n Expected
Manifold Absolute Preisure (MAP) SeiiioiSgnul
Hiqher Than Ex(see page 11-84)
Engine Control Module (ECN4) Power Source Circuil
Serial Communication Link Malfunction
P1106 (13)
P110? (13
P1 108 (ts'
Barometric Pressure (BARO) Sensor Range/
Performance Problem
Barometric Pressure (BARO) Sensor Circuit Low
P1121 11)
P1 129 (5)
P1157 (48)
Pr 158 (48)
Air Fuel Ratio (AVF) Sensor (Sensor 1) Range/
Rerformance Problem
AirFuel Ratio{A"F) Sensor {Sensor 1)AFS Terminal(see page 1 1-85)
Air Fuel Ratio 1AVF) Sensor isensor 'l) AFS + Terminal(see page 1 1-86)
Air Fuel Ratio {A,/F) Sensor {Sensor I ) Slow Response
Air Fuel Ratio (A/F) Sensor (Sensor 1) Range/(see page 1 1-88)
Air Fuel Ratio (4,/F) Sensor (Sensor 1) Heater Circuit
Malfunction
(see page 11-89)
Air Fuel Ratio (A,/F) Sensor (Sensor 1) Heater System
Malfunction
(see page 11-91)
P1 159 (48)
P1163 (61
P1164 (61)
P1 166 (41)
P1 167 (41) '
DTC Troubleshooting Index (cont'd)
" :These DTCS are indicated by a blinking MIL when the SCS servlce signal line is jumped with the Honda PGM
Tester.* 1r '02 model
\
l\."
11-8
\.
(
a

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
\
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11-10
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Fuel and Emissions Systems
System Descriptions (cont'd)
ECM Data (cont'd)
w
DataDescriptionOpera'ting ValueFreeze Data
Fuel System
Status
Fuel system status is indicated as "open" or "closed".
Closed: Based on the A,/F Sensor output, the ECM
determines the airlfuel ratio and controls the amount of
injected fuel.
Open: lgnoring Ay'F Sensor output, the ECM refers to
signals from the throttle position {TP), manifold absolute
pressure (MAP), intake air temperature (lAT), barometric
pressure (BARO), and engine coolant temperature (ECT))
sensors to control the amount of iniected fuel.
At idle speed: closedYES
Short Term
FuelTrim
The airlfuel ratio correction coefficient for correcting the
amount of injected fuel when the fuel system status
is "closed." When the ratio is leaner than the
sloichiometric ratio, the ECM increases short term fuel
trim gradually, and the amount of iniected fuel increases.
The airlfuel ratio gradually gets richer, causing a lower
oxygen content in the exhaust gas. Consequently, the
short term fuel trim is lowered, and the ECM reduces the
amount of injected fuel.
This cvcle keeps the airlfuel ratio close to the
stoichiometric ratio when in closed loop status.
o.7 1.5YES
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.
lf long term fuel trlm is higher than 1.00, the amounl of
injected fuel must be increased. lf it is lower than 1.00, the
amount of injected fuel must be reduced.
0.8 1.2YES
Intake Air
Temperature
{IAT)
The IAT sensor converts intake air temperature into
voltage and signals the ECM. When intake air
temperature is low, the internal resistance ofthe 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
anole of the throttle valve is indicated.
At idle speed:
about 10 %
YES
lgnition
Timing
lgnition timing is the ignition advance angle set by the
ECM. The ECM matches ignition timing to driving
conditions.
At idle speed: 8" t 5"
|' tuL wnen rne >L)
service signal line is
jumped with the Honda
PGM Tester
NO
Calculated
Load Value
(cLV)
cLV is the enoine load calculated from IMAP data.At idle speed:
12 34%
At 2.500 rpm with no
toao:'t4- 34%
YES
11-14
\.,
ra

ECM Inputs and Outputs at Connector A (31P)
NOTE: Standard battery voltage is 12 V.
1AFS]TC2
]GP23IGPl^:^ I -:,6AFS+1
CKPIKS
'10
SG2t112ACV15TPST6AFS_18
VSS
19IVAP2Avcc221vccl
22
HTC+
23LG225CMPA
26CMPB(rDc)
27tGPts,l28rcPts329tGPts230GPLS 1
Wire side ol female terminals
Terminalnumb€rWho colorforminal nameDescriptionSignal
ELKAVHTAFSHTC (AIR FUEL RATIO(4./F)SENSOR HEATERCONTROL}
Drives Ay'F sensor heaterWith ignit'on switch ON {ll): battery voltageWith fully warmed up engine runnang: 0 V
2YEUBLKIGP2 (POWEB SOURCE)Power source for the ECMcircuitWith the ignition switch ON 1ll): battery voltageWith the ionition switch OFF: about 0 V3YEUBLKIGPl {POWER SOURCE)Power source for the ECMWith the ignition swatch ON {ll): battery voltageWith the ionition switch OFF: about 0 V4BLKPG2 (POWER GROUNDGround forthe ECM circuitLess than 1.0 V at all times5BLKPG1 (POWER GROUNDGround forthe ECM circuitLess than 1.0 V at all times6REDAFS + (AIR FUEL RATIO(A,/F}SENSOR, SENSOR 1+ stDE)
Detects Ay'F sensor{sensor 1) signal
18LUCKP (CRANKSHAFTPOSITION SENSOR)Detects CKP sensor signalWith engine running: pulses
9BED/BLU)K SENSOB)Detects knock sensor siqnalWith enqine knocking: pulses10YEL2 {SENSOR;ROUND);ROUND)Sensor qrounrLessthan 1.0V at elltimesG1 {SENSORSensor qroun(Lessthan 1.0V at alltimes12BLIVREDIACV (IDLE AIR CONTROL(IAC)VALVE)Drives IAC valveWith engine runningr duty controlled
RED/BLKTPS (THROTTLE POSITIONSENSOR)Detects TP sensor signalWith throttle fully open: about 4.8 VWith thronle fullv closed: ahout 0-5 VREDI/ELAFS (AIR FUEL RATIO(4,/F)SENSOR, SENSOB 1SIDE)
Detects !y'F sensor(sensor 1)signal
18WHT/GRNVSS (VEHICLE SPEEDSENSOR)Detects VSS signalWath ignition switch ON (lli and front wheelsrotating: cycles from about 0 V to about 5 V or
(cont'd)
11-19

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
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Fuel and Emissions Systems
(
(
(
System Descriptions (cont'dl
Secondary Heated Oxygen Sensor (Secondary HO2S)
The secondary HO2S detects the oxygen content in the
exhaust gas downstream of the three way catalytic
converter (TWC) and sends signals to the ECM which
checks the efficiency of the TWC. To stabilize its output,
the sensor has an internal heater. The secondarv HO2S
is installed in the TWC.
ztRcoNtaELEMENTSENSORTERMINALS
HEATERTERMINALS
Starting Control
When the engine is started, the ECM provides a rich
mixture by increasing injector duration.
Throttle Position ITP) Sensor
The TP sensor is a potentiometer connected to the
throttle valve shaft. As the throttle position changes, the
sensor varies the signal voltage to the ECM. The TP
sensor is not replaceable apart from the throftle body.
ELEMENTBRUSH HOLDER
gRUSH
11-28
Vehicle Speed Sensor (VSS)
The VSS is driven by the differential. lt generates apulsed signal from an input of 5 volts. The number ofpulses per minute increases/decreases with the speed
of the vehicle.
BEARING

Fuel and Emissions Systems
(
{
System Descriptions (cont'd)
ldle Control System
When the engine is cold, the Ay'C compressor is on, the
transmission is in gear, the brake pedal is pressed. thepower steering load is high, or the alternator is
charging, the ECIM controls current to the ldle Air
Control (lAC) valve to maintain the correct idle speed.
Refer to the System Diagram to see the functional
layout of the system.
Brake Pedal Position Switch
The brake pedal position switch signals the ECM when
the brake pedal is oressed.
Electrical Power Steering (EPS) Senser
The EPS sensor signals the ECM when the power
steering load is high.
ldle Air Control llACl Valve
To maintain the proper idle speed, the IAC valve
changes the amount of air bypassing the throttle body
in response to an electrical signal from the ECM.
From AIR To INTAKECLEANER MANIFOLD
IAC VALVE
11-32
Fuel Supply System
Fuel Cut-off Control
During deceleration with the throttle valve closed,
current to the injectors is cut off to improve fuel
economy at engine speeds over 1,030 rpm. Fuel cut-off
action also occurs when engine speed exceeds
6,900 rpm, regardless of the position of the throttle
valve, to protect the engine from over-rewing. When
the vehicle is stopped. the ECM cuts the fuel at engine
speeds over 6,500 rpm.
Fuel Pump Control
When the ignition is turned on, the ECM grounds the
PGM-Fl main relay which feeds current to the fuel pump
for 2 seconds to pressurize the fuel system, With the
engine running. the ECM grounds the PGM-Fl main
relay and feeds current to the fuel pump. When the
engine is not running and the ignition is on, the ECI\4
cuts ground to the PGM-Fl main relay which cuts
current to the fuel pump.
PGM-FI Main Relay 1 and 2
The PGM-Fl main relay consists of two separate relays.
Relay 1 is energized whenever the ignition switch is ON(ll) to supply battery voltage to the ECM power to the
injectors, and power for relay, Relay 2 is energized to
supply power to the fuel pump for 2 seconds when the
ignition switch is turned ON (ll), and when the engine is
runnrng.