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
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.
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.
32. fvleasure voltage between body ground and ECM
connector terminal (see table).
ECM CONNECTOR B (24P)
Wire side of female termrnals
ls there battery voltage?
YES-Go to step 33,
NO Go to step 41.
Turn the ignition switch OFF, and remove the
engine cover.
Disconnect the injector 2P connector from theproblem cylinder.
Measure the resistance between injector 2P
connector terminals No. 1 and No. 2.
INJECTOB 2P CONNECTOR
Terminal side of male terminals
ls there 10 Q 13A?
YES-Go to step 36.
NO Replace the injector (see page 1 1- 11 I ). t
33.
34.
35,
PROBLEM
CYLINDER
DTCEC t\4
TERMINAL
WIRE
COLOR
No. 1P0301B5BRN
No.2P0302B4RED
No.3P0303B3BLU
No.4P0304YEL
36.Exchange the injector from the problem cylinder
with one from another cylinder.
Letthe engine idle for 2 minutes.
Test-drive the vehicle for several minutes in the
range oI the lreeze data or under various
condilions if there was no freeze data.
Check for a DTC or Temporary DTC with the scan
tool.
ls DTC or Temporary DTC P0301, P0302, P0303,
or P0304 indicated?
YES Go to step 40.
NO Intermittent misfire due to injector
malfunction, etc. Make sure the injector
connections are secure. Check for poor connections
or loose terminals at the injector connector.l
Determine which cylinder{s} had the misfire.
Does the mislirc occur in the cylinder whete the
i nj ector w as exchanged ?
YES Replace the faulty injector.l
NO Update the ECM if it does not have the latest
software, or substitute a known-good ECM. then
recheck (see page 1 'l-6). lf the symptom/indication
goes away with a known-good EClvl, replace the
original ECM.I
Turn the ignition switch OFF.
Remove the engine cover.
Disconnect the injector 2P connector from the
problem cylinder.
44. Turn the ignition switch ON (ll)
37.
38.
39.
41.
42.
43.
(cont'd)
11-75
PGM-FI System
a
I
DTC Troubleshooting (cont'dl
45. Measure voltage between injector 2P connector
terminal No. 1 and body ground.
INJECTOR 2P CONNECTOR
tll-z]
,o, ,"=rrrr*, -lt-
oI
Wire side of female terminals
ls there battery voltage?
YES-Go to step 46.
NO-Repair open in the wire between the injector
and the PGM-Fl main relay l.l
Turn the ignition switch OFF.
Check for continuity between body ground and
ECM connector terminal (see table).
46.
47.
ECM CONNECTOR B {24P)
Wire side of female terminals
ls there continuity?
YES-Repair short in the wire between the ECM
and the ;njector.I
NO-Go to step 48.
PROBLEM
CYLINDER
DTCECM
TERMINAL
WIRE
COLOR
No. 1P030'1B5BRN
No.2P0302B4RED
No.3P0303B3BLU
No. 4P030482YEL
11-76
48. Connect injector 2P co nnector term inal No.2 to
body ground with a jumper wire {see table).
INJECTOR 2P CONNECTOR
Wire side of {emale terminals
49. Check for continuity between body ground and
ECM connector terminal (see table).
ECM CONNECTOR B I24P)
Wire side oJ temale terminals
ls therc continuity?
YES Replace the injector, then recheck.l
NO Repair open in the wire between the ECM and
the injector.I
tll-Z-l-]_r-l_rNJ
IJUMPER
IwrBE
PROBLEM
CYLINDER
DTCWIRE COLOR
No. 1P0301BRN
No.2P0302RED
No. 3P0303BLU
No. 4P0304YEL
PROBLEM
CYLINDER
DTCECM
TERMINAL
WIRE
COLOR
No. 1P0301B5BRN
No. 2P0302B4RED
No. 3P0303B3BLU
No. 4P030482YEL
DTG P0325: Malfunction in Knock Sensor
Circu it
1. Reset the ECM (see page 11-4).
2. 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.
3. Hold the engine at 3,000-4,000 rpm for at least
60 seconds.
ls DTC P0325 indicated?
YES-Go to step 4.
NO Intermittent failure, system is OK at this time.
Check for poor connections or loose terminals at
the knock sensor and at the ECM.I
4. Turn the ignition switch OFF.
5. Disconnect the starter subharness 6P connector.
6. Check for continuity between ECM connector
terminal Ag and body ground.
ECM CONNECTOR A 131P)
Wire side of lemale terminals
ls there continuity?
YES-Repair short in the wire between the ECM(A9) and the starter subharness 6P connector.l
NO Go to step 7.
7. Connect staner subharness 6P connector terminal
No. 5 to body ground with a jumper wire.
8.
STARTER SUAHARNESS6P CONNECTOR
l1l213ll,/l5l6l._
KS IJUMPER|RED/BLU) IW|REI
Wire side of female terminals
Check for continuity between body ground and
ECM connector terminal A9.
9.
ECM CONNECTOR A {31PI
Wire side of female terminals
ls there continuity?
YES-Go to step 9.
NO Repair open in the wire between the ECM (A9)
and the starter subharness 6P connector.l
Check the starter subharness between the 6P
connector and the knock sensor for an open or
short. lf it's OK, substitute a known-good knock
sensor and recheck.
ls DTC P0325 indicated?
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 sym ptomlindication
goes away with a known good ECM, replace the
original ECM.I
NO Replace the original knock sensor and/or
sta rte r subharness.l
11-77
PGM-FI System
a
a
DTC Troubleshooting (cont'd)
DTC P0335: CKP Sensor No Signal
DTC P0336: CKP Sensor Intermittent
Interruption
'1. Reset the ECM (see page 1 '1-4).
2. Sta rt the engine.
ls DTC P0335 and/or P0336 indicated?
YES Go to step 3.
NO Intermittent failure, system is OK at this time.
Check for poor connections or loose terminals at
the CKP sensor and at the ECM.I
3. Turn the ignition switch OFF.
4. Disconnect the CKP sensor 3P connector.
5. Turn the ignition switch ON {ll).
6. Measure voltage between CKP sensor 3P connector
terminal No.3 and body ground.
CKP SENSOR 3P CONNECTOF
(YEL/BLK}
Wire sade of female terminals
Is there battery voltage?
YES- Go to step 7.
NO Repair open ln the wire between PGM-Fl main
relay 1 and the CKP sensor.!
IGP
123
11-78
7. Measure voltage between CKP sensor 3P connector
terminal No, 1 and body ground
CKP SENSOR 3P CONNECTOR
Wire side of female tef minals
ls there about 5 V?
YES Go to step L
NO Go to step 10.
8. Measure voltage between CKP sensor 3P connector
terminals No.2 and No. 3.
CKP SENSOR 3PCONNECTOR
,llYtLL"l
(LGl{BRN/YELI
Wire side of female terminals
ls there battery voltage?
YES Go to step 9.
NO Repair open in the wire between the CKP
sensor and G 101 .I
9. Substitute a known-good CKP sensor and recheck.
ls DTC P0335 and/or P0336 indicated?
YES 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
NO Replace the original CKP sensor.l