2002 HONDA CIVIC engine

DTC P0134: Ay'F Sensor (Sensor 1) No Activity
Detected
1. Check the attachment state of the A,/F sensor(Sensor 1).
ls it slacked f rom the exhaust pipe?
YES- Reinstall the Ay'F sensor (Seneor 1) (see page
11-113).t
NO-Go to step 2.
2. Reset the ECM (see page 1 1-4).
3. Stan the engine. Hold the engine speed at
3,000rpm with no load (in neutral) until the radiator
fan comes on, then let it idle for 2 minute.
ls DTC PO134 indicated?
YES-Replace the Ay'F sensor {Seneor 1) (see page
11-113).t
NO - Intermittent failu re, sistem is OK at this time.
Check for poor connections or loose terminals at
the Ay'F sensor (Seneor 1 ) and the ECM.I
DTC P0137: Secondary HO2S (Sensor 2)
Circuit Low Voltage
1. Reset the ECM (see page I1-4)
2. Start the engine. Hold the engine at 3,000 rpm wilh
no load (in neutral) until the radiator fan comes on.
3. Check the secondary HO2S (Sensor 2) output
voltage at 3,000 rpm with the scan tool.
ls there 0.3 V or less?
YES Go to step 4.
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 HO2S (Sensor 2) 4P
connector.
Turn the ignition switch ON (ll).
Check the secondary HO2S (Sensor 2) output
voltage with the scan tool.
ls there 0.3 V or less?
YES Go to step 8.
NO Replace the secondary HO2S (Sensor 2).1
Turn the ignition switch OFF.
Disconnect ECM connector E (31P).
icont'd)
4.
5.
6.
7.
8.
9.
11-65

PGM-FISystem
aDTC Troubleshooting (cont'dl
10. Check for continuity between the secondary HO2S(Sensor 2) 4P connector terminal No. 2 and bodygrou nd.
SECONDARY H02SISENSOR 2) 4P CONNECTOR
Terminal side of male terminals
ls there continuity?
YES-Repair shon in the wire between the ECM(E2) and the secondary HO2S (Sensor 2). t
NO Update the ECM if it does not have the latest
software, or substitute a known-good ECM, then
recheck (see page 1 1-6). lf the symptom/indication
goes away with a known-good ECM, replace the
original ECM.I|
11-66
DTC P0138: Secondary HO2S (Sensor 2)
Circuit High Voltage
1. Resetthe ECM {see page'11-4).
2. Startthe engine. Hold the engine at 3,000 rpm with
no load (in neutral) until the radiator fan comes on.
3. Check the secondary HO2S (Sensor 2) output
voltage at 3,000 rpm with the scan tool.
ls thete 1.0 V or morc?
YES Go to step 4.
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
4. Turn the ignition switch OFF.
5. Disconnect the secondary HO2S (Sensor 2) 4P
connector.
Connect secondary H02S (Sensor 2) 4P connector
terminals No. 1 and No. 2 with a jumper wire.
SECONDARY HO2S{SENSOR 2) 4P CONNECTOR
JUMPER WIRE
SG3 (PNKISHO25 (WHT/RED)
Terminal side oJ male terminals
7. Turn the ignition switch ON (ll).

8.Check the secondary H02S (Sensor 2) output
voltage with the scan tool,
ls there 1.0 V ot mote?
YES-Go to step 9.
NO Replace the secondary HO2S (Sensor 2).1
Turn the ignition switch OFF.
Connect ECM connector terminals E2 and E4 with a
JUmper wrre.
ECM CONNECTOR E 131PI
Wire side of female terminals
Turn the ignition switch ON (ll).
Check the secondary HO2S (Sensor 2) output
voltage with the scan tool.
ls there 1.0 V or more?
YES Update the ECM if it does not have the latest
soflware, or substitute a known-good ECM, then
recheck (see page 1 1-6). lf the symptom/indication
goes away with a known-good ECM. replace the
original ECM.I
NO Repair open in the wire between the ECM (E2,
E4) and the secondary HO2S {Sensor 2).I
9.
10.
11.
12.
JUMPER WIRE
3.
DTC P0139: Secondary HO2S (Sensor 2l Slow
Response
1. Resetthe ECM (see page 11-4).
Start the engine. Hold the engine at 3,000 rpm with
no load (in neutral) until the radiator fan comes on.
Check the secondary HO2S (Sensor 2) output
voltage at 3,000 rpm with the scan tool.
ls thete 0.3- 0.8 V, fot 2 minutes?
YES Replace the secondary HO2S (Sensor 2).!
NO- lntermittent failure, system is OK at this time.
Check for poor connections or loose terminais at
the secondary HO2S (Sensor 2) and at the ECM.I
11-67

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

DTC P0300: Random Misfire and Any Combination of the Following:
DTC P0301: No. 1 Cylinder Misfire
DTC P0302: No. 2 Cvlinder Misfire
DTC P0303: No, 3 Cvlinder Misfire
DTC P0304: No. 4 Cvlinder Misfire
NOTE:. lfthe misfiring is frequent enough to trigger detection of increased emissions during two consecutive driving cycles.
the MIL will come on, and DTC P0300 (and some comlrination of P0301 through P0304) will be stored.. lf the misfiring is frequent enough to damage the catalyst, the MIL will blink whenever the misfiring occurs, and OTC
P0300 (and some combination of P0301 through P0304) will be stored. When the misfirlng stops, the MIL will remain
on.
1. Troubleshoot the following DTCs first if any of them were stored along with the random misfire DTC(s):
P0'107, P0108, P1128, P1129r N4anifold absolute pressure (MAP) sensor
P0111. P0'172t Fuel svstem
P0335. P0336: Crankshaft position (CKP) sensor
P0505: ldle control system
P1 149, Pl 162, P1 163, P1 164, P 1 165: Air fuel ratio (Ay'F) sensor
P1259: VTEC system
P1361, P1362: Camshaft position (CMP) sensor B {Top dead center (TDC) sensor)
P1519: ldle air control (lAC) valve
2. Test-drive the vehicle to verify the symptom.
3. Findthesymptom inthechart below, and dothe related procedures in the order listed until you find the cause.
SymptomProcedure(slAlso check foi:
Random misfire only
at low RPM and
under load
Check fuel pressure (see page 1 1-145).. Low compressron.. Low quality fuel.
Random misfire only
du ring acceleration
Check fuel pressure (see page 11-145).Malfunction in the
VTEC system (see page
1't-123).
Random misfire at
high RPM, under
load, or under
random conditions
Check fuel pressure (see page 11-145).Correct engine valve
clearances (see page 6-
91.
11-71

PGM-FI System
IDTC Troubleshooting (cont'dl
DTC P0301: No. 1 Cylinder Misfire
DTC P0302: No. 2 Cylinder Misfire
DTC P0303: No. 3 Cylinder Misfire
DTC P0304: No. 4 Cylinder Misfire
1. After checking and recording the freeze data, reset
the ECM (see page 1 1-4). lf there is no freeze data of
the misfire, just clear the DTC.
2. Start the engine, and listen for a clicking sound
from the injector at the problem cylinder.
Does the injector click?
YES-Go to step 3.
NO-Go to step 30.
3. Turn the ignition switch OFF.
4. Exchange the ignition coil from the problem
cylinder with one from another cylinder,
5. Test-drive the vehicle for several minutes in the
range of the freeze data or under va rious
conditions if there was no freeze data.
6. Check for a DTC or a Temporary DTC with the scan
root.
ls DTC or Tempotaty DTC P0301, P0302, P0303
or P0304 ind icated?
YES Go to step 7.
NO Intermittent misfire due to poor contact at the
ignition coil connectors {no misfire at this time).
Make sure the coil connections are secure.l
11-72
8.
9.
1.
11.
Determine which cylinder(s) had the misfire.
Does the misf ire occur in the cylinder where the
ignition coil was exchanged?
YES Replace the faulty ignition coil.!
NO-Go to step 8.
Turn the ignition switch OFF.
Exchange the spark plug from the problem cylinder
with one from another cylinder.
Test-drive the vehicle for several minutes in the
range of the freeze data or under various
conditions if there was no freeze data.
Check for a DTC or Temporary DTC with the scan
Tool.
ls DTC ot Tempotary DTC P0301, P0302, P0303
or P0304 ind icated?
YES Go to step 12.
NO Intermittent misfire due to spark plug fouling,
etc. (no misfire at this time).1
Determine which cylinder(s) had the misfire.
Does the misl ire occur in the cylinder where the
spark plug was exchanged?
YES Replace the faulty spark plug.l
NO Go to step 13.
Turn the ignition switch OFF.
Exchange the lnjector from the problem cylinder
with one from another cylinder.
Let the engine idle for 2 minutes.
10.
14.
t5.

PGM-FI System
aDTC Troubleshooting (cont'dl
26. Check for continuity between body ground and
ECM connector terminal (see table).
ECM CONNECTOR A {31PI
PROB LE IVI
CYLINDER
DTCECM
TERMINAL
WIRE
COLOR
No. 1P0301430YEUGRN
No.2P0302A.29BLU/RED
No.3P0303428WHT/BLU
No,4P0304421BRN
ls there continuity?
YES Repair shon in the wire between the EClvl
and the ignition coil.l
NO-Go to step 27.
27. Connect ignition coil 3P con nector term inal No. 1to
body ground with a jumper wire (see table).
IGNITION COII 3PCONNECTOR
Wire s de of femaleterminals
PROBLEM
CYLINDER
DTCWIRE COLOR
No. 1P0301YEUGR N
No. 2P0302BLU/RED
No. 3P0303WHT/BLU
No. 4P0304BRN
11-74
28. Check for continuity between body ground and
ECM connector terminal (see table).
ECM CONNECTOR A {31P}
PROBLEM
CYLINDER
DTCECM
TERI\4INAL
WIRE
COLOR
No. 1P0301A30YEL/GRN
No. 2P0302429BLU/RED
No. 3P0303A.28WHT/BLU
No. 4P0304A.21BRN
ls there continuity?
YES-Go to step 29.
NO Repair open in the wire between the ECM and
the ignition coil.l
29. Check the engine compression
ls the compression OK?
YES-Update the ECM if it does not have the latest
software, or substitute a known-good ECM, then
recheck (see page 11-6). lf the symptom/indication
goes away with a known-good ECM, replace the
original ECI\4.I
NO- Repair the engine.l
Disconnect ECM connector B (24P).
Turn the ignition switch ON (ll).
30.