Page 301 of 1395
Engine Goolant Temperature (ECTI Sensor
The scan tool indicates Diagnostic Trouble Code (DTC) P0116: A range/performance problem in the Engine
Coolant Temperature (ECT) Sensor circuit.
The ECT Sensor is a temperature dependant resistor (thermistor). The resistance of the thermistor decreases as the engine
coolant temperature increases as shown below
RESISTANCEtk0l
NOTE: lf DTC P0117 and/or P0118 are stored at the same
bleshoot DTC P0116.
Possible Cause
a ECT sensor deterioration
. Malfunction in the thermostat and cooling system
Troubleshooting Flowchart
-4 32 68 r0a r a0176 212 2aE {'r)-2O O 20 ito tO .o ! t2O I c)
ENGINE COOLANT TEMPERATURE
time as DTC P0116, troubleshoot those DTCS first, then trou-
THERMISTON
- The MIL has be€n roported on.- DTC P01'16 is stored.
Probl6m verification:1. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neutral) untilthe radiator fan comes on,then let it idle.2. With the scan tool, check theECT.
Intermittent failure, sYstem b OKat this tim6. Check lhe thermo-stat and the cooling 5y3tom.
ls 176 - 200'F (80 - 93"C) or0.4-0.TVindicated?
Check the thermostat and the
cooling system. It th€y are OK,reolace the ECT seNor.
(cont'd)
1 1-99
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Page 331 of 1395
(From page 11-128)
lntormittent misfire due lo sparkplug fouling, etc. (no mislire at
this tim€).
ls DTC P0301, P0302, P0303,or P0304 indicated?
ooes the misfire occur in theother cylinder?Replace the faulty spark Plug.
Check lor fuel iniector maltunc-
t|on:1. Exchange the fuel injectorfrom the problem cylinderwith one from another cylin-der.2. Let the engine idle for two min
utes.3. Test'drive the vehicle severaltimes in the range of the freezedata,
lntermittent misfiro due lo bad
contrct in the fuel iniector con-nector {no misfire at this time).
ls DTC P0301, P0302, P0303,or P0304 indicated?
Does the misfire occur in theother cylinder?Replace lhe faulty luel inlector.
Check following items- Valvo clearance- Cvlinder l€ak-down- Compression- Crsnkshaft Speed FluctuationICKF) sensol
NOTE: lf there is no freeze data of misfiring, test drives under various condi_
tions are necessary.
11-129
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Page 339 of 1395
Barometric Pressure (BARO) Sensor
The scan tool indicates Diagnostic Trouble Code (DTC) P1106: A range/performsnce problem in the Barometric
Pressure {BARO) Sensor circuit.
The MIL has been reDorted on.OTC Pl106 b slored.
Problem ve.ification:1. Oo the ECM/PCM reset pro'
ceoure.2. Start the engine. Hold theengine at 3,000 rpm with noload (;n Park or neutral) untilthe radiator lan comes on, thenlet it idle.3. Connect the SCS service con-nector,4. Test'drive with the A/T in Eposition, M/T in 4th gear.
5. Accelerate Ior five secondsusing wide open throttle.
Intermittent fsilure, sy3tom i5 OKat this time.ls DTC P1106 indicated?
Substitute a known-good ECM/PCM .nd recheck. It symptom/indication goes away, replace theorigioal ECM/PCM.
fTiloz l
tP11o8l
The scan tool indicates Diagnostic Trouble Code (DTC) P1107: A low
The scan tool indicates Diagnostic Trouble Code (DTC) Pl108: A
circuit.
voltage problem in the Baro sensor circuit.
high voltage problem in the Baro sensor
- The MIL h.3 b€en roport€d on.- OTC Pl10? or Pl108 i3 stored.
Problom veritic.lion:L Do the ECM/PCM Reset Pro-cedure.2. Turn the ignition switch ON (lli.
Intarmittoni failure, lystom b OKat thb time.ls DTC P1107 or P1108 indicated?
Sub3tituto a known-good ECM/PCM and rcch6ck. ll symptom/indication 9oo3 away. .oplacorho o.igin.l ECM/PCM.
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Page 342 of 1395
PGM-FI System
Electrical Load Detestor (ELDI (USA Model) (cont'dl
The scan tool indicates Diagnostic Trouble Code {DTC) Pl298; A high voltage problem in the Electrical Load
Detector (ELD) circuit.
97 modsl:
ELD 3P CONNECTOR {C35,'I
Wire sido oI lemale terminals
r lzlrl--T_ow
/6 IBLKI
Y
Repail op€n in th. wire b€tws€ntho No. 15 ALTERNATOR SPSENSOR 17.5 A) tuse in theunder-dlrh fuso/r.lay box andth6 ELD.EL {GRN/NEDI
PCM CONNECTORS
Problam verification:1. Do the PCM Reset Procedure.2. Start the engine.3. Turn on the headlights.Intermittent tailuro, systcm is OK.t this time. Chack for ooor con-noction! or looro wire3 at C127{locaied on PCM brackot), C35{{ELDI and .t tho PCM.
Chack for an opan in tho wilellGl linol:1. Turn thg ignition and head-lights OFF.2. Disconnect the ELD 3P connector.3. Turn the ignition switch ON {ll).4. M6asure voltage b€tw€enbody ground and the ELD 3Pconnoctor terminal No. 1.
Chock lol !n open in the wireIGND linel:'1. Turn the ignition switch andheadlights OFF.2. Disconnect the ELD 3P conneqor,3. Check for continuity betweenbody ground and the ELD 3Pconnector terminal No. 2.
Ropair opon in th6 wi.e betweonth. ELD connector rnd GiO2,
Ch.ck lo. an open in th€ wiro (EL
line):Check for continuity between theELD 3P connector terminal No. 3and PCM connector terminal 016.
Chock for . malfunction in theELD:1. Reconnect the ELD 3P con-neclor,2. Start the engine and allow itto idle.3. While measuring voltagebetween PCM connector terminals 016 and A9. turn theheadlights on (low).
ls there continuityT
R6pafu op6n in tho wire betweenthe PCM {D161snd th6 ELD.
Subltituto . known-good PCMand rachock, f symptom/indic.-tion goes awry, ropl.ce the origi-n.l PCM.
Does the voltage drop?
Wire side of lemale terminals
11-140
Wire side of lemale terminals
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Page 343 of 1395
38 - 00 modeb:
Problem verification:1. Do the ECM/PCM Reset Proceoure.2. Stan the engine.3- Turn on the headlights.Intermittent feilure, sysl.m is OKat this time. Check for ooor con-nections or loose wires at C354(ELDI and at the ECM/PCM.
ls DTC P1298 indicated?
Check lor an open in the wire(lG1 line):'1. Turn the ignition and head-lights OFF.2. Disconnect the ELD 3P connector.3. Turn the ignition switch ON (ll).
4, Measu re voltage betweenbody ground and the ELD 3Pconnector terminal No. '1.Reprir open or short in th6 wirebotweon the No. 15 ALTERNA-TOR SP SENSOR {7.5 Al fuse inthe under-drah fuse/relay boxand the ELD.
Check tor an opon in tho wire{GND line}:1. Turn the ignition switch andheadlights OFF.2. Disconnect the ELD 3P connector.3. Check for continuity betweenbody ground and the ELD 3Pconnector terminal No. 2,
Repair opon in the wire betweenthe ELD conneclor and GilO2.
Ched( fo. an op€n in the wir€ (EL linel:Check for continuity between theELD 3P connector terminal No. 3and ECM/PCM connector termi-nalA30.
Repair op€n in tha wile botwecnthe EcM/PCM lA30l .nd rhe ELD.
Check for s malfunction in lhe ELD:1. Reconnect the ELD 3P con-nector.2. Start the engine and allow itto idle.3. While measuring voltagebetween ECM/PCM connectorterminals A30 and 820, turnthe headlights on (low).
Substiiute a known-good ECM/PCM and recheck. It symptom/indication goos away, replacethe original ECM/PCM.
ELO 3P CONNECTOR {c35/rl
Wire side of female terminals
Wire side of female terminals
Wire side ot temale terminals
ELD 3P CONNECTOR {C35,lt
EL IGRN/RED}Wire side of femaletermrnars
ECM/PCM CONNECTORS
A l32P)
11-141
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Page 351 of 1395
ldle Control System
System Description
The idle speed of the engjne is controlled by the ldle Air Control (lAC) Valve'
The valve changes the amount of air bypassing into the intake manifold in response to electric current controlled by the
ECM/PCM. When the lAc valve is activated, the valve opens to maintain the proper idle speed.
YEL/ From PGM'FI
BLK TMAIN RELAY
VARIOUSSENSORS
4.
IAC VALVE
INTAKE MANIFOLD
After the engine starts, the IAC valve opens for a certain time. The amount of air is increased to raise the idle speed
about 150 - 300 rpm.
when the cootant temperature ts row, the lAc valve is opened to obtain the proper fast idle speed The amount o{
bvoassed air is thus controlled in relation to the engine coolant temperature
When the idle speed is out o{ specification and the scan tool does not indicate Diagnostic Trouble Code (DTC) P0505
or P1508, check the following items:
. Adjust the idle speed (see page 11-169, 170)
. Air conditioning signal (seepagell-1551
. ALT FR signal (see page 1l-159)
. Starter switch signal (see page 11-16'1)
. A,/T gear position signal (see section 14)
. PSP switch signal (seepagell-162)
. Brake switch signal (see page 11-165)
. Fast idlethermovalve (see page'11 168)
. Hoses and connecttons. IAC valve and its mounting O-rings
lf the above items are normat, suDslitute a known-good IAC valve and readjust the idle speed {see page 11-169, 170)
lf the idle speed still cannot be adjusted to specification (and the scan tool does not indicate DTC P0505 or Pl508)
after IAC valve reolacement, substitute a known-good ECM/PCM and recheck lf symptom goes away' replace the
original ECM/PCM.
11-149
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Page 352 of 1395
ldle Control System
ldle Control System
I P0505 | The scan tool indicates Diagnostic T.ouble Code (DTCI PO5O5: ldlecontrol svstem mattunction.
NOTE: lf DTC P1508 is stored at the same time as DTC P0505, troubleshoot DTC P1508 first. then troubleshoot DTC p0505.
Possibls Cause
. IAC valve mechanical malfunction. Throttle body clogged port, improper adlustment. Intake manifold gasket leakaging. Intake air hose loose leakaging. Vacuum hose leakaging
a ECT sensor incorrect output. Throttle Position sensor incorrect output
Troubleshooting Flowchart
The MIL has been reDorted on.DTC P0505 is sto.ed.
Problem verificationi1. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neutral) untilthe radiator Ian comes on, thenlet it idle.2. With the scan tool, check thelollowing items.- Throttle position should beapprox. 10% with the throt-tle {ully closed.- Engine coolant temperature shorJld be 194 - 205'F(90 - 96"C).lf they are not within thespec., repair the faulty sen-sor circuit.3 Check the engine speed atidle with no-load conditions:headlights, blower fan. reardefogger, radiator lan, and airconditioner are not operaling,
Inte.mittent failure. syltem is OKat this time.ls it 750 {730)* i 50 rpm?
ls il 700 (680)' rpm or less?
{To page 11-151)(To page 1'l-151)
l:'99 - 00 models
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Page 353 of 1395
(From page 11-150)
{From page 11-150}
THERMO VALVE(A/T onlyl
Check the IAC valve:Disconnect the 2P connector from
the IAC valve.
Does the engine speed droP
or the engine stall?
Adiust the (basel idl€ speed lseepage 11-169, 1t0). Itihe ba3e idle
speed cannot be adiust€d, clean
the Dorts in the throttle body.
UPPER
Check the tast idle lhermo valve:
1. Turn the ignition switch OFF.
2. Remove the intake air ductfrom the throttle body.3. Start the engine and let it idle.
4. Put your finger on the lowerpon in the throttle body.
Check engine cool.nt level and for
air in the cooling sy3lem. lf OK,
reolace the f.st idle thermo valve.Does the engine speed drop?
Put your Iinger on the uPPer Portin the throttle body.
Check for vacuum leaks, make
sure the throttle valve is com'pletely clo3ed. and repair as nec-Does the engine speed droP?
Adjust the idle spoed lsee Page11-169. 1701. lf the adiustmentdoes not correct lhe problem,
r.olace the IAC valve.
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