2003 HONDA CIVIC Body

PGM-FI System
DTC Troubleshooting (cont'dl
DTC P0122: TP Sensor Circuit Low Voltage
1. Turn the ignition switch oN (111.
2. Check the throttle position with the scan tool.
ls there about 10./. or 0.5 V when the thrcttle is
fully closed and about 90% or 4.5 V when the
throttle is fully opened?
YES Intermittent failure, system is OK at this time.
Check for poor connections or loose terminals at
the TP sensor and at the ECM. t
NO Go to step 3.
3. Turn the ignition switch OFF,
4. Disconnect the TP sensor 3P connector.
5. Turn the ignition switch ON (ll).
6. Measure voltage between the TP sensor 3P
connector terminals No. 1 and No. 3.
TP SENSOR 3P CONNECTOR
Wire side of female terminals
ls there about 5 V?
YES-Go to step 7.
NO Go to step 14.
Turn the ignition switch OFF.1.
11-60
8. At the sensor side, measure resistance between the
TP sensor 3P connector terminals No. 1 and No. 2
with the throttle fully closed.
TP SENSOR 3P CONNECTOR
Terminal side of male terminals
Is there about 0.5 0.9 kQ ?
YES Go to step 9.
NO Replace the throttle body (the TP sensor is not
available separately). I
Measure resistance between the TP sensor 3P
connector terminals No. 2 and No. 3 with the
throttle fully closed.
TP SENSOR 3P CONNECTOB
Terminal side of male terminals
ls there about 4.5k{l ?
YES Go to step 10.
NO Replace the throttle body (the TP sensor is not
available separately). I
10. Disconnect ECM connector A (31P).
9.\

11. At the wire harness side, check for continuity
between TP sensor 3P connector terminal No, 2
and body ground.
TP SENSOR 3P CONNECTOR
1 1213
'PS
REO
Wire side ot Iemale terminals
ls thete continuity?
YES-Repair short in the wire between the ECM
{A15) and the TP sensor.ll
NO-Go to step 12.
Connect ECM connector terminal A15 to body
ground with a jumper wire.
ECM CONNECTOR A 131P)
1121345679
1011112tc68 19 t2021
2312428129130
,tf$,rr*, ] ;uueen wrne
Wire side oJ .female terminals
/BLKI
12.
13. At the wire harness side, check for continuity
between TP sensor 3P connector terminal No. 2
and body ground.
TP SENSOR 3P CONNECTOR
(RED/BLX}
Wire side of female terminals
ls there continuity?
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 ECM.I
NO- Repair open in the wire between the ECM
(A15) and the TP sensor.l
14. lvleasure voltage between ECM connector
terminals 410 and A20.
ECM CONNECTOB A 131P}
vcc2(YEL/8LU)
Wire side of female terminals
ls there about 5 V?
YES Repair open in the wire betlveen the ECM
(A20) and the TP sensor.I
NO Update the ECM if it does nor have the latest
software, or substilute a known-good ECM, then
recheck (see page 1 1-6). lf the symplom indication
goes away with a known-good ECM. replace lhe
original ECM.I
123
TPS
11-61

PGM-FI System
(
(
DTC Troubleshooting (cont'd)
DTC P0123: TP Sensor Circuit High Voltage
1. Turn the ignition switch oN (ll)
2. Check the throttle position with the scan tool.
ls there about 10% or 0.5 V when the throttle is
fully closed and about 90% or 4.5 V when the
throttle is f ully opened?
YES lntermittent failure. system is OK at this time.
Check for poor connections or loose terminals at
the TP sensor and at the ECM, I
NO Go to step 3.
3. Turn the ignition switch OFF.
4. Disconnect the TP sensor 3P connector.
5. Turn the ignition switch ON (ll).
6. At the wire harness side, measure voltage between
the TP sensor 3P connector terminals No. 1 and
No.3.
TP SENSOR 3P CONNECTOR
W;re side of female terminals
ls thete about 5 V?
YES-Replace the throttle body (the TP sensor is
not available separately). I
NO Go to step 7.
11-62
7. Measure voltage between ECM connector
terminals A10 and A20.
ECM CONNECTOR A 131PI
Wire side of female terminals
Is there about 5 V?
YES- Repair open in the wire between the ECM(A10) and the TP sensor. t
NO Update the ECM if it does not have the latest
soflware, or substitute a known-good ECM, then
recheck (see page 11-6). lf the symptom/indicationgoes away with a known-good ECM, replace the
original ECM.I

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).

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)

1 1. Check for continuity between ECM connector
terminal E6 and body ground.
ECM CONNECTOR E {31PI
Wire side o{f Iemale terminals
ls therc continuity?
YES-Repair short in the wire between the ECM
(E6) and the secondary HO2S (Sensor 2).1
NO-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
Measure voltage between secondary HO2S
(Sensor 2) 4P connector terminal No. 4 and body
g rou nd.
SECONDARY HO2S {SENSOR 2I 4P CONNECTOR
tFff I
l[faJl--ro'14 | IBLK/OFN)
YI
Terminal side of male terminals
ls there battety voltage?
YES Go to step 13.
NO-Checkthe No. 4 ACG (10A) fuse in the under-
dash fuse/relay box. lf the fuse is OK, repair open in
the wire between the secondary HO2S (Sensor 2)
and No. 4 ACG (10A) fuse.l
13.
14.
t5.
to.
Turn the ignition switch OFF.
Reconnect the secondary HO2S (Sensor 2) 4P
connector.
Disconnect ECM connector E (31P).
Turn the ignition switch ON (ll).
Measure voltage between ECM connector terminal
E6 and A5.
ECM CONNECTORS
A (31 P)
E {31 P}
Wire side ot female terminals
Is there 0-1 V or less?
YES-Repair open in the wire between the ECM
(E6) and the secondary HO2S (Sensor 2). !
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. a
17.
11-69

16.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 a Temporary DTC with the scan
Tool.
ls DTC or Temporary DTC P0301, P0302, P0303
or P0304 indicated?
YES Go to step 18.
NO lntermittent misfire due to bad contact at the
injector connector (no misfire at this time). Make
sure the injector connection is secure. Check for
poor connections or loose terminals at the
injector.l
Determine which cylinder(s) had the misfire.
Does the misf ire occur in the cylinder where the
i njector w as exchanged ?
YES- Replace the faulty injector.I
NO-Go to step 19.
Turn the ignition switch OFF.
Disconnect the ignition coil 3P connector from the
problem cylinder.
Turn the ignition switch ON (ll).
't7 .
18.
19.
20.
22. Measure voltage between ignition coil 3P
connector terminal No. 3 and body ground.
IGNITION COIL 3P CONNECTOR
Wire side ol female terminals
ls there battery voltage?
YES-Go to step 23.
NO Repair open in the wire between the No. 1
IGN COIL (15A)fuse and the ignition coil.I
Turn the ignition switch OFF.
Check for continuity between ignition coil 3P
connector terminal No. 2 and body ground.
IGNITION COIL 3P CONNECTOR
Wire side ot female terminals
ls there continuity?
YES Go to step 25.
NO Repair open in the wire between the ignition
coiland G101.1
Disconnect ECM connector A {31P)
23.
24.
(cont'd)
11-73

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.