2003 HONDA CIVIC heater troubleshooting

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

PGM-FISystem
3.
DTC Troubleshooting (cont'dl
DTC P0141: Secondary HO2S (Sensor 2l
Heater Circuit Malfunction
1. Reset the ECM (see page 1 l-4)
2. Start the engine.
ls DTC P0141 indicated?
YES-Go to step 3.
NO-lntermittent failure, system is OK at this time.
Check for poor connections or loose terminals at
the secondary HO2S (Sensor 2) and at the ECM.I
Turn the ignition switch OFF.
Disconnect the secondary H02S (Sensor 2) 4P
connecror.
At the secondary HO2S (Sensor 2) side, measure
resistance between H02S 4P connector terminals
No.3 and No. 4.
SECONDARY HO2S (SENSOR 21 4P CONNECTOR
Wire side ol lemale terminals
ls there about 3.3 Q ?
YES Go to step 6.
NO- Replace the secondary HO2S (Sensor 2). t
5.
11-68
6. Check for continuity between body ground and
secondary H02S (Sensor 2) 4P connector terminals
No.3 and No. 4 individually.
SECONDARY HO2S {SENSOR 21 4P CONNECTOR
Wire side of female terminals
ls there continuity?
YES- Replace the secondary HO2S (Sensor 2).1
NO-Go to step 7.
Turn the ignition switch ON (ll).
Measure voltage between secondary H02S 4P
connector terminals No. 3 and No. 4,
SECONDARY HO2S (SENSOR 2l ilP CONNECTOR
t
7.
8.
9.
10.
s02sHTc{BLK/WHTIIG1 (BLK/ORN}
Terminal side of male terminals
ls there battery voltage?
YES Go to step 9.
NO Go to step 12.
Turn the ignition switch OFF.
Disconnect ECM connector E {31P)

PGM-FI System
DTC Troubleshooting (cont'dl
DTC P0171: Fuel System Too Lean
DTC P0172: Fuel System Too Rich
NOTE: lf some of the DTCS listed below are stored at
the same time as DfC PO17'l and/ot PO172,
troubleshoot those DTCS first, then recheck for P0171
andlot P0112.
P0107, P0108. P1 128. P1 129: Manifold absolute
pressure (MAP) sensor
P1 162. P1 166, P 1 167: 4,,/F sensor (Sensor 1 ) heater
P0137, P0138: Secondary HO2S (Sensor 2)
P014'l: Secondary HO2S (Sensor 2) heater
P1259: VTEC system
1. Check the fuel pressure (see page 11-'145).
ls luel pressure OK?
YES Go to step 2.
NO Check these items:
. lf the pressure is too high, replace the fuel
pressure regulator (see page 11-152).1. lf the pressure istoo low.checkthefuel pump,
the fuel feed pipe, the fuel filter, and replace the
fuel pressure regulator (see page 11-152).I
2. Start the engine. Hold the engine at 3,000 rpm with
no load (in neutral) until the radiator fan comes on.
11-70
3. Turn the ignition switch OFF.
4. With a vacuum pump, apply vacuum to the
evaporative emission (EVAP) canister purge valve
(A) from the evaporative emission (EVAP) canister
side.
' A973AX-041-XXXXX
Does it hold vacuum?
YES-Check the engine valve clearances and adjust
if necessary, lf the valve clearances are OK, replace
the injectors (see page 1 1-1 1 1).1
NO-Replace the EVAP canister purge valve.l

ldle Control System
ldle Speed lnspection
NOTE:' Leave the idle air control (lAC) valve connecled.. Before checking the idle speed, check these items:- The malfunction indicator lamp (MlL) has not been
reported on.- lgnition timing- Spark plugs- Air cleaner- PCV system. Pullthe parking brake lever up. Start the engine, and
make sure the headlights are off.
1. Disconnect the evaporative emission (EVAP)
canister purge valve 2P connector.
2. Connect a tachometer (A)to the test tachometer
connector (B), or connect the Honda PGM Tester (C)
or an OBD ll scan tool to the data link connector(DLC) (D) located under the driver's side of the
dashboard.
11-138
4.
3.
5.
6.
Start the engine. Hold the engine at 3,000 rpm with
no load (in neutral) until the radiator fan comes on,
then let it idle.
Check the idle speed with no-load conditions;
headlights, blower fan, radiator fan, and air
conditioner off.
ldle speed should be: 750 t 50 rpm
Let the engine idle for 1 minute with the heater fan
switch on Hl and air conditioner on, then check the
idle speed.
ldle speed should be: 750 t 50 rpm
NOTE: lf the idle speed is not wilhin specification,
go to the Symptom Troubleshooting Index,
Reconnect the EVAP canister purge valve 2P
connector.

Catalytic Converter System
DTC Troubleshooting
DTC P0420: Catalytic System Efficiency
Below Threshold
NOTE: lf some of the DTCS listed below are stored at
the same time as DTC P0420, troubleshoot those DTCS
first, then recheck for DTC P0420.
P0137, P0138: Secondary Heated Oxygen Sensor(secondary HO2S) (Sensor 2)
P0141: Secondary HO2S (Sensor 2) heater
1. Reset the ECM {see page 1'l-4}, then continue to
step 2 through 5 to reset the readiness code.
2. Start the engine. Hold the engine at 3,000 rpm with
no load (in neutral) untilthe radiator fan comes on.
Drive for about l0 minutes without stopping. Your
speeo can vary.
With the transmission in 4th gear, drive at a steady
speed between 50 62 mph (80-'100 km/h) for
30 seconds.
Repeat step 4 three times. Between each repetition,
close the throttle completely for 1 2 seconds. lf
the engine is stopped during this part of the
procedure, repeat steps 3, 4 and 5.
Check for a Temporary DTC with the scan tool.
Does the scan tool indicate Temporaty DTC
P0420?
YES Check the TWC. lf necessary, replace the
TWC.I
NO Check for readiness code completion. lfthe
readiness is complete, it was a interminent failure,
and the system is OK at this time. lf the readiness
code is incomplete, repeat steps 2 through 5.1
4.
11-167

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z t-'5
z t-o
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21-9
21-10
21-11
21-14
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HVAC (Heating, Ventilation, and Air Gonditioningl
Heating and Air Conditioning
SpecialTools
Comoonent Location lndex ........
A/C Service Tios and
Precautions
A,/C Refrigerant Oil
ReDlacement
General Troubleshooting
lnformation
DTC Troubleshooting Index .......
Symptom Troubleshooting
1ndex..............
System Description .....................
Circuit Diagram
DTC Troubleshooting ..................
Recirculation Control Motor
CircuitTroubleshooting .......... 21-25
Heater Control Power and Ground
Circuits Troubleshooting ........ 21-27
Condenser Fan Circuit
Troubleshooting ...................... 21-28
Radiator and Condenser Fans
Common Circuit
Troubfeshooting ...................... 21-29
Compressor Clutch Circuit
Troubleshooting ...................... 21-30
A,/C Pressure Switch Circuit
Troubleshooting ...................... 21-32
Air Mix Control Motor
Test and Reolacement ............. 21-34
Mode Control Motor
Test and Replacement ............. 21-35
Recirculation Control Motor
Test and Reolacement ............. 21-36
Evaporator Temperature Sensor
Reolacement and Test ............. 21-31
Power Transistor Test ................. 21 -38
Heater Control Panel and
Push Switch Assemblv
Removal and Installation ........ 21-38
Dust and Pollen Filter
Reolacement ..21-39
Blower Unit Removal and
lnstallation ...... 21-39
Blower Unit Comoonents
ReDlacement ............................ 21-41
Evaporator Core
Reolacement ..21-42*Heater Unit/Core
ReDlacement ..21-43
Heater Valve Cable
Adjustment .....21-46
CompressorReplacement .......... 21-47
Comoressor Clutch Check .......... 21-48
Comoressor Clutch Overhaul ..... 21-49
Compressor Thermal Protector
Reo1acement ............................ 21-51
Comoressor Relief Valve
Reolacement ............................ 21-51
Condenser Reolacement ............ 21-52
Refrigerant Recovery .................. 21-53
System Evacuation ...................... 21-54
System CharginS ......................... 21-55
Refrigerant LeakTest .................. 21-56
A,/C Svstem Tests ........................ 21-57

Heating and Air Conditioning
General Troubleshooting Information
How to Retrieve a DTC
The heater control panel has a self-diagnosis function. To run the self-diagnosis function, do the following:
1. Turn the fan switch OFF.
2. Pressand holdthe recirculation control switch andthe rear window defoooer switch down.
3. Turn the ignition switch oN {lli.
4. Release both switches. The recirculation indicator and the rear window defogger indicator come on. The
recirculation indicator goes off 3 seconds later and the Ay'C indicator comes on. then the self-diagnosis will begin.
About 10 seconds later, the self-diagnosis will finish and the A,/C indicator goes off.
.lfanytroubleisfound.therecirculationindicatorblinksthediagnostictroublecode(DTC)toindicateafaulty
circuil or comDonent.. lf the system is OK, the recirculation indicator stays off.
atc
@r
RECIRCULATIONCONTROL SWITCH
BECIRCULATIONINDICATOB
/A\
-:@
INOICATOR
REAR WINDOWOEFOGGER INDICATOR
REAR WINDOWDEFOGGER SWITCH
Examole of DTC indication Pattern IDTC 7)
DTC 7
Reseiting the Selt-diagnosis Function
Turn the ignition switch OFF to cancel the self-diagnosis function. After completing repair work, run the self-diagnosis
function aoain to make sure thatthere are no other malfunctions.
Recirculation +indicatot
Recirculation +indicalorgo6s oft----->
21-8