How to Read Flowcharts
A flowchart is designed to be used from start to final repair. lt's like a map showing you the shortest distance. But beware:
lf you go off the "map" anywhere but a "stop" symbol, you can easily get lost.
brARn
t.-OotO tw"t Describes the conditions or situation to start a troubleshooting flowchart.
FcTloNl Asks you to do something; perform a test, set up a condition etc.
@ Asks you about the result of an action, then sends you in the appropriate troubleshooting direction.
fS-OPl The end of a series of actions and decisions, describes a final repair action and sometimes directs you to
(bold type) an earlier part of the flowchart to confirm your repair.
NOTE:
. The term "lntermittent Failure" is used in these charts. lt simply means a system may have had a failure, but it checks
out OK at this time. lf the Malfunction Indicator Lamp (MlL) on the dash does not come on, check for poor connections
or loose wires at all connectors related to the circuit that you are troubleshooting (see illustration below).
. Most of the troubleshooting flowcharts have you reset the Engine Control Module (EcM)/Powertrain Control Module(PCM) and try to duplicate the Diagnostic Trouble Code (DTC). lf the problem is intermittent and you can't duplicate the
code, do not continue though the flowchart. To do so will only result in confusion and, possibly, a needlessly replaced
ECM/PCM,
o "Open" and "Short" are common electrical terms. An open is a break in a wire or at a connection. A short is an acci-
dental connection of a wire to ground or to another wire. ln simple electronics, this usually means something won't
work at all. In complex electronics (like ECM'S/PCM'S), this can sometimes mean something works, but not the way it's
suooosed to.
LOOSE
11-79
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Fuel Cut-off Control
. During deceleration with the throttle valve closed, current to the fuel injectors iscutoffto improvefuel economyat
speeds over 970 rpm ('97 - 98 models), 920 rpm ('99 - 00 modelsl.
. Fuel cut-off action also takes place when engine speed exceeds 6,500 rpm ('97 - 98 models), 6900 rpm ('99 - 00
models), regardless of the position of the throttle valve, to protect the engine from over-rewing.
With Ay'T model. the PCM cuts the fuel at engine speeds over 5,000 rpm when the vehicle is not moving.*'
4,./C Comoressor Clutch Relav
When the ECM/PCM receives a demand for cooling from the air conditioning system, it delays the compressor from
being energized, and enriches the mixture to assure a smooth transition to the Ay'C mode.
Evaporative Emission (EVAP) Purge Control Solenoid Valve
When the engine coolant temperature is above 154"F (68'C), the ECM/PCM controls the EVAP purge control solenoid
valve which controls vacuum to the EVAP purge control canister,
Alternator Control
The system controls the voltage generated at the alternator in accordance with the electrical load and driving mode.
which reduces the engine load to improve the fuel economy.
PCM Fail-saf e/Back-up Functions
1. Fail-safe Function
When an abnormality occurs in a signal from a sensor, the ECM/PCM ignores that signal and assumes a pre-pre
grammed value for that sensor that allows the engine to continue to run.
2. Back-up Function
When an abnormality occurs in the ECM/PCM itself, the fuel injectors are controlled by a back-up circuit independent
of the system in order to permit minimal driving.
3. Self-diagnosis Function IMalfunction Indicator Lamp (MlL)l
When an abnormality occurs in a signal from a sensor, the ECM/PCM supplies ground for the MIL and stores the DTC
in erasable memory. When the ignition is initially turned on {ll), the ECM/PCM supplies ground for the MIL for two
seconds to check the MIL bulb condition.
4. Two Trio Detection Method
To prevent false indications, the Two Trip Detection Method is used for the HO2S*1, fuel metering-related. idle control
system, ECT sensor and EVAP control system self-diagnostic functions. When an abnormality occurs, the ECM/PCM
stores it in its memory. When the same abnormality recurs after the ignition switch is turned OFF and ON (ll) again,
the ECM/PCM informs the driver by lighting the MlL. However, to ease troubleshooting, this function is cancelled
when you jump the service check connector, The MIL will then blink immediately when an abnormality occurs.
5. Two (or Three) Driving Cycle Detection Method {'97 model)
A "Driving Cycle" consists of starting the engine, beginning closed loop operation, and stopping the engine. lf misfir-
ing that increases emissions or EVAP control system malfunction is detected during two consecutive driving cycles.
or TWC deterioration is detected during three consecutive driving cycles, the ECM/PCM turns the MIL on. However, to
ease troubleshooting, this function is cancelled when you jump the service check connector. The MIL will then blink
immediately when an abnormality occurs.
*1: '97 - 98 models*2: '99 - 00 models
5.
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NOTE:. When there is no Diagnostic Trouble Code (DTC) stored, the MIL will stay on if the SCSservice connector is connected and the ignition switch is on.. lf this svmotom is intermittent, check for:- A loose Fl E/M (15 Aifuse in the underdash tuse/relay box- A loose No. 13 FUEL PUMP {15 A) fuse in the under-dash fuse/relay box- An intermittent short in the wire between the PCM (C7) and the service check con-
- An intermittent short in the wire between the PCM (A18) and the gauge assembly- An intermittent shon in the wire betlveen the PCM (D4) and the MAP sensor- An intermiftent short in the wire between the PCM {D10) and the TP sensor.PGM-Fl main relay.'See the OBD ll scan tool or Honda PGM Tester user's manuals lor specilic operatinginstructions,
NOTE: An open or short in the wire between the PCM (C8) and the DLC will keep thescan tool or Honda PGM Tester lrom communicating with the PCM. You should ioterpretthis as no DTCS are indicated.
PCM CONNECTORc l3lPl scs .BRNI
lTo page 11 84)Wire sid6 of f€male terminalg
(cont'dl
11-83
The Malfunciion lndicator Lamo{MlL) stavs on o. comes on afteltwo seconds,
Check the Oiegnosiic TroubleCode (DTC):
1. Connect an OBD ll scan toolor Honda PGM Tester.2. Turn the ignition switch ON 1lli.3. Read the DTC with the scantool or Honda PGII Tester.
Go to troubleshooting procedures(s€€ page 11501.Are any DTCIs) indicated?
Ch6ck lh6 DTC by MIL indication:1. Turn the ignition switch OFF.2. Connect the SCS service con-nector to the service checkconnector.3. Turn the ignition switch ON (ll).
- Repair opon or short in wi.6between the PCM (C8) andData Link Connector.- Go to troubloshooting proce-
dur€s {3ee page 11-601.
Does the MIL indicate any DTc?
Try to start the engine.
Does the engine start?
Check tor a short in the wire{SCS line):1. Turn the ignition switch OFFand turn the ignition switchoN flt).2. Measure voltage between thePCM connector terminal C7and body ground.
Repair short to body ground inthe wire between PCM lCTl andservice check connector.ls there approx. 5 V?
(To page 1'l-84)
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PGM-FI System
Engine Control Module/Poweftrain Control Module (ECM/PCM) -'98 - 00 Models (cont'dl
NOTE:. When there is no Diagnostic Trouble Code IDTC) stored, the MIL will stay on iI the SCSservice connector is connected and the ignition switch is ON (ll).. lf this symptom is intermittent, check for:- An intermittent short in the wire between the ECM/PCM (A10) and the service checkconnoctor- An intermittent short in the wire between the ECM/PCM (At8l and the gaugeassemDty. See the OgD ll scan tool or Honda PGM Tester user's manuals for specific operatingrnstructions.
ECM/FCM CONNECTOF A {32P)
Wire side of femsle t6rminals
The Malfunction lndicator LamolMlll 3lays on or comes on aftertwo 3econds.
Check the Dirgnostic TroubloCod€ (DTCI:'1. Connect a scan tool or HondaPGM Tester.2. Turn the ignition switch ON (ll).3. Read the DTC with the scantool or Honda PGM Tester.
Go to troublGhooting procadura.(3€c prg€ l lS0l
check tho DTc by MIL indication:1. Turn the ignition switch OFF.2. Connect the SCS service con-nector to the service checkconnector,3. Turn the ignition switch ON (ll).
Ropair op.n ol Bhort in wirob.twe.n thc ECM/FCtrl (A21)
and D.i. Link Connoctor.Go to troublo3hootlng proc€-dur6. lt o pag. 11.6lrl
Does the MIL indicate any DTC?
Try to start the engine.
Sub3titute r known"good ECM/PCM .nd roch.ck. lt .ymptom/indic.tion gooa awsy, repl.cothe origin.l ECM/PCM.
Does the engine stan?
Check tor a 3hort in the wireISCS linel:1. Turn the ignition switch OFFand turn the ignition switchoN { ).2- Measure voltage betweenbody ground and the ECM/PCi, conneclor terminal A10.
Ropria ahort to body ground intho wi.c Mwe.n tho ECM/PCMlA10l and aarvic. check connsc-tor.
lTo page 1l-89)
11-88
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PGM-FI System
Manifold Absolute Pressure (MAPI Sensor
The scan tool indicates Diagnostic Trouble Code (DTC) POl07: A low input (high vacuum) problem in theManifold Absolute Pressure (MAP) sensor,
The MAP sensor convens manifold absolute pressure into electrical signals and inputs the ECM/pCM.
OUTPUIVOLTAGE
tvl3.s
3.0
2.5
2.O
1.5
1.0
0.5
o .5 ro- 15^ 1olin.H9) GAUGEREADIT{G
lmmHgl
3025
100 200 300 a00 5oo 6fi, 7d)
MAP SENSOR 3P CONNECTOR IC131I
vccl(YEL/RED}
Th6 MIL has b€en reoorted on.DTC P0107 is 3tored.
Problom verification:1. Turn the ignition switch ON lll).2. Check the lvlAP with the scanroot.
lrtormittem tailu.e, lystam b OKat thb timo. Check tor poor con-noctions or loosa wird at C131(MAP rensor) and rt the ECM/PCM.
ls approx. 101 kPa (760 mmHg,30 in.Hg),2.9 V indicated?
Check for an op6n in wi.o IVCC1linel:1. Turn the ignition switch OFF.2. Disconnect the MAP sensorconnector,3. Turn the ignition switch ON {ll}.4. Measure voltage between theMAP sensor connector No. 1termanal and No. 2 terminal.
Roprir op€n in the wir6 bstweentho ECM/PCM (D4, C19*l and theMAP sensor.
ls there approx. 5 V?
(To page 11-91)
11-90
Wiro side ol temale terminals
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PGM-FI System
Manifold Absolute Pressure (MAP) Sensor (cont'd)
[tn,t nn-] The scan tool indicates Diagnostic Trouble Code (DTC) P0108: A high voltage (low vacuum) problem in the|jg Manifold Absolute Pressure (MAP) sensor.
MAP SENSOR 3P CONNECTOR IC131I
Wire side of female terminals
vcclIYEL/RED}
PCM CONNECTOR D I16PI
JUMPER WIRE
sGlIGRN/WHTI
Wire side of lemale termin6ls
1
(To page 11,93)': '98 - 00 models
1-92
tcRN/wHrll IIRED/GRN|
The MIL has boen reported on.DTC m108 is slored.
Problem veritication:1. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neutral) untilthe radiator fan comes on, thenlet it idle.2. Check the MAP with the scantool.
Intermittent tailuro, system i3 OKat this time. Check tor ooor con-nections or loose wires at C131IMAP s6nsor) snd the ECM/rcM.
ls 101 kPa {760 mmHg,30 in.Hg),2.9 V or higher indicated?
Check Ior an open in the MAPsensor:1. Turn the ignition switch OFF.2. Disconnect the MAP sensor3P connector.3. lnstall a jumper wire betweenthe MAP sensor 3P connectorterminals No.3 and No.2.4. Turn the ignition switch ON {ll).5. Check the MAP with the scantool.
ls 10'l kPa (760 mmHg,30 in.Hg),2.9 V or higher indicated?
Check for an open in wire (SGlliDel:1. Remove the jumper wire.2. Measure voltage between theMAP sensor 3P connector ter-minals No. 1 and No- 2.
R6p.ir open in the wire betwoenthe ECM/PCM (D12, CTrl and theMAP sensor.
ls there approx. 5 V?
Check for an open in the wire(MAP line):1. Turn the ignition switch OFF.2. lnstall a iumper wire on thePCM connectors between D3and D12.3. Turn the ignition switch ON (ll).4. Check the MAP wirh the scantool.
Ropair opon in the wire betweenthe PCM {D3, .nd the MAP son-3('t.
ls 101 kPa 1760 mmHg, 30 in.Hg),2.9 V or higher indicated?
YES
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PGM-FI System
Manifold Absolute Pressure (MAP) Sensor (cont'dl
The scan tool indicates Diagnostic Trouble Code (DTC) P1128: Manifold Absolute pressure (MAp) lower thanexoected.
The scan tool indicates Diagnostic Trouble Code (DTC) P'l129: Manifold Absolute Pressure (MAP) higher thanexpected.
l
- The MIL has be6n r€ported on.- DTC Pl128 is stored.
Problom verification:1. Turn the ignition switch ON 1lli.2. Check the MAP with the scantool,
ls 54.1 kPa (406 mmHg, 16.0 in.Hg),1.61 V or higher indicated?I to.mittent failure, 3ydom i! OKal thbtimc,
- The MIL has boen reportod on.- DTC Pl129 is stored.
Problem veritication:1. Start the engine. Hold theengine at 3,000 rpm with noload lin Park or neutral) untilthe radiator fan comes on,then Iet it idle.2. Check the MAP with the scantool,
ls 43.3 kPa (325 mmHg, 12.8 in.Hg),'1.32 V or less indicated?Intarmittani fuilure, systom i3 OKat this time.
11-94
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The IAT Sensor is a temperature dependant resistor (thermistor). The resistance of the thermistor decreases as the intake
air temDerature increases as shown below
RESISTANCE IKOI
Intake Air Temperature (lAT) Sensor
1P0111 | ('97 model)The scan tool indicates Diagnostic Trouble code (DTC) P0111: A ranoe/performance problem in
the lntake Air TemDerature (lAT) Sensor circuit.
. 3' aa ro. r?a arl ,.t r.fl20 0 to ao ao aa ioo t2otocl
INTAKE AIB TEMPERATURE
- The MIL has been reported on.- DTC P0111 is stored.- Or lrom Probable Cause List.
Problem vetification:1. Turn the ignition switch OFF.
2. Disconnect the IAT sensor 2P
connector,3. Remove the IAT sensor.4. Reconnect the IAT sensor 2P
connector,5. Leave the IAT sensor etposedto ambient temPerature.6. Turn the ignition switch ON
flr).7. check the IAT with the scan
tool-
R€place the IAT son3or.
Check the IAT sensor output:1. Warm the IAT sensor with ahair dryer.2. Check the IAT with the scan
tool.
Did the IAT rise 2.0'F (1.0'C)
or more from the ambienttemperature?
Intermittent f.ilure, aY3tem is OKai this tim6.
Replace the IAT sensor.
(cont'd)
1 1-95
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