Troubleshooting
Troubleshooting Procedure s
Symptom Char t
Listed below are symptoms and probable causes for problems that DO NOT cause the Malfunction Indicator Lamp (MIL) to
come on. If the MIL was reported on, check the DTC.
Troubleshoot each probable cause in the order listed (from left to right) until the symptom is eliminated.
The probable cause and troubleshooting page reference can be found below.
SYMPTO M
Engine wil l no t star t
Hard startin g
Col d fas t idl e to o lo w
Col d fas t idl e to o hig h
Idl e spee d fluctuate s
Misfire o r roug h runnin g
Low powe r
Engin e stall s
Difficul t t o refue l
Fuel overflow s durin g refuelin g PROBABL
E CAUS E
2, 3 , 21 , 13 , 1
2 , 10 , 12 , 20 , 2 1
5, 6 , 7 , 4
5 , 6 , 7 , 9 , 8
5 , 14 , 15 , 6 , 7 , 9 , 8
Troubleshoo t fo r misfir e o n page
s 11-59 , 11-60
2 , 8 , 9 , 11 , 18,17 , 19 , 1 0
2, 5 , 10 , 21 , 7 , 3 , 1 6
20 , 2 2
20 , 2 2
Other Probable Causes for an engine that will not start:
— Compressio n — Starting syste m
— PGM-F I mai n rela y — Ignitio n syste m
— Engin e locke d u p — Overheatin g
— Timin g bel t — Battery
Probable Caus e
1
2
3
4
5
6
7
8
9
10
1 1
1 2
13
1 4
15
1 6
17
1 8
1 9
2 0
2 1
22
Pag e
11-6 6
(see DTC chart)
(see DTC chart)
(see DTC chart)
Sectio n 1 4
11-8 1
(see DTC chart)
11-10 6
System
Powertrai n Contro l Modul e (PCM )
Fue l pressur e
Crankshaf t Position/Camshaf t Positio n (CKP/CMP ) (Crankshaf t Position/Cylinde r Positio n
(CKP/CYP) ) senso r circui t
Intak e Ai r Temperatur e (IAT ) senso r circui t
Idl e Ai r Contro l (IAC ) valv e
Idl e Ai r Contro l (IAC ) therma l valv e
Idl e spee d adjustmen t
Throttl e bod y
Throttl e cabl e
Manifol d Absolut e Pressur e (MAP ) senso r
Throttl e Positio n (TP ) senso r
Barometri c pressur e (BARO ) senso r
Transmissio n rang e switc h signa l
Ai r conditionin g signa l
Alternato r F R Signa l
Brake peda l positio n switc h signa l
Ai r cleane r
Intak e Manifol d Runne r Contro l (IMRC ) syste m an d intak e ai r duc t
Thre e Wa y Catalyti c Converte r (TWC )
Evaporativ e emissio n (EVAP ) contro l
Contaminate d fue l
Fue l tan k vapo r contro l valv e
Probable Cause List (For the DTC Chart, see page 11-41)
(see DTC chart)
(see DTC chart)
(see DTC chart)
(see DTC chart)
11- 132
11- 123
11- 124
11- 155
11- 154
11- 116
11- 118
11- 155
11- 158
ProCarManuals.com
Engine Coolant Temperature (ECT) Sensor
The HDS or the scan tool indicates Diagnostic Trouble Code (DTC) P0116: A range/performance problem in the
Engine Coolant Temperature (ECT) sensor.
The ECT Sensor is a temperature dependent resistor (thermistor). The resistance of the thermistor decreases as the engine
coolant temperature increases as shown below.
NOTE: If DTC P0117 and/or P0118 are stored at the same time as DTC P0116 and/or P0125, troubleshoot those DTCs first,
then troubleshoot DTC P0116 and/or P0125.
Possible Cause
• ECT sensor deterioration
• Malfunction in the thermostat and the cooling system
Troubleshooting Flowchart
— The MIL has been reported on.
— DTC P0116 is stored.
Problem verification:
1. Turn the ignition switch OFF.
2. Check the ETC output tempera-
ture or voltage with the HDS or
the scan tool.
Is about 176°F (80°C) or high-
er, or 0.86 V or less indicated?
YES
Problem verification:
1. Note current coolant
temperature.
2. Turn the ignition switch OFF.
3. Cool the engine for 1 hour.
4. Check the ETC output temper-
ature or voltage with the HDS
or the scan tool.
Does the ECT change 3.6°F
(2°C) or more?
NO
Replace the ECT sensor.
NO
YES
Problem verification:
1. Note current coolant
temperature.
2. Start the engine. Hold the
engine speed at 3,000 rpm
with no load (in Park or neu-
tral)
until
the
radiator
fan
comes on, then let it idle.
3. Check the ETC output temper-
ature or voltage with the HDS
or the scan tool.
Does the ECT change 3.6°F
(2°C) or more?
NO
YES
Intermittent failure, system is OK
at this time. Check the thermo-
stat and the cooling system.
Intermittent failure, system is OK
at this time. Check the thermo-
stat and the cooling system.
(cont'd)ProCarManuals.com
PGM-FI System
Engine Coolant Temperature (ECT) Sensor (cont'd)
The HDS or the scan tool indicates Diagnostic Trouble Code (DTC) P0125: Engine Coolant Temperature
(ECT) sensor malfunction/slow response.
Is about 86°F (30°C) or less, or
2.61 V or higher indicated?
Intermittent failure, system is OK
at this time.
Check the thermostat and the
cooling system.
YES
Problem verification:
1. Let it idle for 6 minutes.
2. Check the ETC output temper-
ature or voltage with the HDS
or the scan tool.
Is about 86°F (30°C) or less, or
2.61 V or higher indicated?
Intermittent failure, system is OK
at this time.
Check the thermostat and the
cooling system.
YES
Replace the ECT sensor.
11-50
Problem verification:
1. Start the engine, and let it idle.
2. Check the ETC output temper-
ature or voltage with the HDS
or the scan tool.
— The MIL has been reported on
— DTC P0125 is stored.ProCarManuals.com
PGM-FI System
Primary Heated Oxygen Sensor (HO2S) (Sensor 1) (cont'd)
Troubleshooting Flowchart
Is DTC P0133 and/or P0153
indicated?
NO
YES
Intermittent failure, system is OK
at this time. Check for poor con-
nections or loose terminals at
C251, C254 (located at right shock
tower), C119 (right primary H02S
(Bank 1, Sensor 1)) or C126 (left
primary H02S (Bank 2, Sensor
1))*
and
PCM.
— The MIL has been reported on.
— DTC P0133 and/or P0153
stored.
Problem verification:
1. Do the PCM Reset Procedure.
2. Start the engine. Hold the
engine at 3,000 rpm with no
load (in Park or neutral) until
the radiator fan comes on.
3. Connect the SCS service con-
nector.
4. Test-drive under following
conditions.
— 55 mph (88 km/h) steady
speed
— Transmission in posi-
tion
— Until readiness code comes
on
Replace the primary HO2S (Sen-
sor 1).ProCarManuals.com
The HDS or the scan tool indicates Diagnostic Trouble Code (DTC) P0134: Right Primary Heated Oxygen Sensor
(Right Primary HO2S) (Bank 1, Sensor 1) heater system malfunction.
The HDS or the scan tool indicates Diagnostic Trouble Code (DTC) P0154: Left Primary Heated Oxygen Sensor
(Left Primary H02S) (Bank 2, Sensor 1) heater system malfunction.
The MIL has been reported on.
DTC P0134 and/or P0154 are
stored.
Problem verification:
1. Do the PCM Reset Procedure.
2. Start the engine. Hold the
engine at 3,000 rpm with no
load (in Park or neutral) until
the
radiator
fan
comes
on.
Is DTC P0134 and/or P0154
indicated?
YES
Check for an open in the HO2S:
1. Turn the ignition switch OFF.
2.
Disconnect
the
right primary
H02S (Bank 1, Sensor 1) or left
primary HO2S* (Bank2, Sen-
sor 1) connector.
3. Install a jumper wire on the
harness side of the right prima-
ry H02S (Bank 1,Sensor 1) or
left primary H02S*connector
between terminals No. 1 and
No. 2.
4. Turn the ignition switch ON (II).
5. Check the right primary HO2S
(Bank 1, Sensor 1) or left pri-
mary HO2S*(Bank2, Sensorl)
output voltage with the HDS
or the scan tool.
Is there 1.5 V or more?
YES
Check for an open in the wires
(PHO2S line):
1. Turn the ignition switch OFF.
2. Install a jumper wire on the
PCM connector between D19,
orD18*andD22.
3. Turn the ignition switch ON (II).
4. Check the right primary H02S
(Bank 1, Sensor 1) or left pri-
mary H02S* (Bank 2, Sensor 1)
output voltage with the HDS
or the scan tool.
Is there 1.5 V or more?
YES
NO
Intermittent failure, system is OK
at this time. Check for poor con-
nections or loose terminals at
C251, C254 (located at right shock
tower), C119 (right primary H02S
(Bank 1, Sensor 1)) or C126 (left
primary H02S (Bank 2, Sensor 1))*
and
PCM.
Replace the HO2S.
Repair open in the wire between
PCM (019 or D18*) and right pri-
mary HO2S (Bank 1, Sensor 1) or
left primary HO2S* (Bank 2,
Sensor 1).
Substitute a known-good PCM and
recheck. If symptom/indication
goes away, replace the original
PCM.ProCarManuals.com
PGM-FI Syste m
Primar y Heate d Oxyge n Senso r (HO2S ) (Senso r 1 ) (cont'd )
The HD S o r th e sca n too l indicate s Diagnosti c Troubl e Cod e (DTC ) P2195 : A lo w voltag e proble m in th e Righ t
Primar y Heate d Oxyge n Senso r (H02S ) (Ban k 1 , Senso r 1 ) circuit .
The HD S o r th e sca n too l indicate s Diagnosti c Troubl e Cod e (DTC ) P2197 : A lo w voltag e proble m in th e Lef t
Primar y Heate d Oxyge n Senso r (HO2S ) (Ban k 2 , Senso r 1 ) circuit .
— Th e MI L ha s bee n reporte d on .— DT C P219 5 and/o r P219 7 ar e
stored .
Proble m verification :
1 . D o th e PC M Rese t Procedure .
2 . Star t th e engine . Hol d th e
engin e a t 3,00 0 rp m wit h n oloa d (i n Par k o r neutral ) unti lthe radiato r fa n come s on .3. Test-driv e wit h th e transmis -sion in [2 ] position .4. Chec k th e righ t primar y HO2 S
(Ban k 1 , Senso r 1 ) o r lef t pri -
mar y HO2S * (Ban k 2 , Senso r
1 ) outpu t voltag e wit h th e sca n
too l durin g acceleratio n usin g
wide ope n throttle .
Is DT C P219 5 and/o r P219 7indicated ?
Does i t sta y a t 0. 5 V or less ?
YES
(To pag e 11-55 )
NO
Intermitten t failure , syste m is O K
a t thi s time . Chec k fo r poo r con -
nection s o r loos e terminal s a tC251 , C25 4 (locate d a t righ t shoc k
tower) , C11 9 (righ t primar y H02 S
(Ban k 1 , Senso r 1) ) o r C12 6 (lef tprimar y HO2 S (Ban k 2 , Senso r1))* an d PCM .
NORepai r fue l suppl y system .
Replac e th e HO2S .
*:P015 1
Check fo r a shor t i n th e HO2S :1. Tur n th e ignitio n switc h OFF .2. Disconnec t th e righ t primar yH02S (Ban k 1 , Senso r 1 ) o r
lef t primar y HO2S * (Ban k 2 ,
Senso r 1 ) connector .
3. Star t th e engin e an d le t i t idle .4. Chec k th e righ t primar y H02 S
(Ban k 1 , Senso r 1 ) o r lef t pri -
mar y H02S * (Ban k 2 , Senso r
1) outpu t voltag e wit h th eHD S o r th e sca n tool .
I
s i t normal ?
Chec
k th e fue l pressure .
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PGM-FI System
Fuel Supply System (cont'd)
Troubleshooting Flowchart
— The MIL has been reported on.
— DTC P0171, P0172, P0174 and/
or P0175 are stored.
Check the fuel pressure.
Is the fuel pressure OK?
NO
YES
Check the Primary HO2S:
1. Start the engine. Hold the
engine at 3,000 rpm with no
load (in Park or neutral) until
the radiator fan comes on.
2. Check the right primary or left
primary* H02S (Sensor 1) out-
put voltage with the HDS or
the scan tool.
Is the fuel pressure too high
or too low?
Check the fuel pressure regulator
and fuel return pipe.
LOW
Check the fuel pump, fuel feed
pipe, fuel filter, and fuel pressure
regulator.
Does it stay at less than 0.3 V
or more than 0.6V?
Replace the HO2S.
NO
Check for a sticking or leaking
EVAP canister purge valve:
With a vacuum pump, apply vacu-
um to the EVAP canister purge
valve from the intake manifold
side.
Does it hold vacuum?
Replace the EVAP canister purge
valve.
YES
Check the EGR system. If it is OK,
replace the fuel injectors.
*: P0174 or P0175ProCarManuals.com
PGM-FI Syste m
Crankshaf t Position/Camshaf t Positio n (CKP/CMP ) (Crankshaf t
Position/Cylinde r Positio n (CKP/CYP) ) Senso r
The HD S o r th e sca n too l indicate s Diagnosti c Troubl e Cod e (DTC ) P0345 : A malfunctio n i n th e circui t o f th e
Crankshaf t Positio n (CKP ) senso r 1 .
Th e HD S o r th e sca n too l indicate s Diagnosti c Troubl e Cod e (DTC ) P0349 : A n intermitten t interruptio n proble m of
th e Crankshaf t Positio n (CKP ) senso r 1 .
Th e HD S o r th e sca n too l indicate s Diagnosti c Troubl e Cod e (DTC ) P0390 : A malfunctio n in th e circui t o f th e Camshaf t
Positio n (CMP ) (Cylinde r Positio n (CYP) ) senso r 1 .
Th e HD S o r th e sca n too l indicate s Diagnosti c Troubl e Cod e (DTC ) P0394 : A n intermitten t interruptio n proble m
o f th e Camshaf t Positio n (CMP ) (Cylinde r Positio n (CYP) ) senso r 1 .
Th e HD S o r th e sca n too l indicate s Diagnosti c Troubl e Cod e (DTC ) P1336 : A n intermitten t interruptio n proble m o f
th e Crankshaf t Positio n (CKP ) senso r 2 .
I Th e HD S o r th e sca n too l indicate s Diagnosti c Troubl e Cod e (DTC ) P1337 : A malfunctio n i n th e circui t o f th e
' Crankshaf t Positio n (CKP ) senso r 2 .
Th e HD S o r th e sca n too l indicate s Diagnosti c Troubl e Cod e (DTC ) P1386 : A n intermitten t interruptio n proble m
o f th e Camshaf t Positio n (CMP ) (Cylinde r Positio n (CYP) ) senso r 2 .
Th e HD S o r th e sca n too l indicate s Diagnosti c Troubl e Cod e (DTC ) P1387 : A malfunctio n i n th e circui t o f th e
Camshaf t Positio n (CMP ) (Cylinde r Positio n (CYP) ) senso r 2 .
Th e CK P Senso r determine s timin g fo r injectio n an d ignitio n o f eac h cylinde r an d als o detect s engin e speed .
Th e CM P (CYP ) Senso r detect s th e positio n o f No . 1 cylinde r fo r sequentia l injectio n t o eac h cylinder . Th e CKP/CM P
(CKP/CYP ) Senso r i s installe d behin d th e fron t camshaf t pulley .
— Th e MI L ha s bee n reporte d on .— DT C P0345 , P0349 , P0390 ,P0394, P1336 , P1337 , P138 6
and/o r P138 7 ar e stored .
Proble m verification :
1. D o th e PC M Rese t Procedure .2. Star t th e engine .
Check fo r a n ope n i n th e CKP /CMP (CKP/CYP ) sensor :1. Tur n th e ignitio n switc h OFF .2. Disconnec t th e CKP/CM P(CKP/CYP) 8 P connector .3. Measur e resistanc e betwee nthe terminal s o f th e indicate dsensor (se e table) .
Is ther e 65 0 - 85 0 fl ?
YE S
Chec k fo r a shor t i n th e CKP /CMP (CKP/CYP ) sensor :Check fo r continuit y t o bod ygroun d o n bot h terminal s o f th eindicate d sensor .
CKP PICK-U PCOIL 2
CM P (CYP ) PICK-U PCOIL 1
N O
Intermitten t failure , syste m is O Kat thi s time . Chec k fo r poo r con -nection s o r loos e terminal s a tC251 , C25 5 (locate d a t righ t shoc ktower) , C13 0 (CKP/CM P (CKP /CYP)) senso r an d PCM .
Replac e th e CKP/CM P (CKP/CYP )sensor (se e sectio n 6) .
CK P PICK-U PCOIL1
CMP (CYP ) PICK-U PCOIL 2
CKP/CM P (CKP/CYP ) SENSO R 8 P CONNECTO R
(To pag e 11-65 )Termina l sid e o f mal e terminal s
Is DT C P0345 , P0349 , P0390 , P0394 ,P1336, P1337 , P138 6 and/o r P138 7indicated ?
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