1998 HONDA INTEGRA ground

3.Fuel Cut-off Control
. Du ring dece leration with the th rottle va lve closed, cu rrent to the fuel injectors is cutoffto improvefuel economyat
speeds over following rpm:. B'1881 engine: 970 rpm {Canada model: 1.050 rpm). B18C1 engine:970 rpm {Canada model: 1.050 rpm). 818C5 engine: 1,300 rpm (Canada model: 1,400 rpm)
. Fuel cut-off action also takes place when engine speed exceeds 7,000 rpm (B'1881 engine), 8.100 rpm (818C1
engine) or 8,600 rpm (818C5 engine), regardless ol the position of the thronle valve, to protect the engine from
over-revving.
A,,/C ComDressor Clutch Relav
When the ECM receives a demand for cooling from the air conditioning system, it delays the compressor from being
energized, and enriches the mixture to assure smooth transition to the A,/C mode.
Evaporative Emission (EVAP) Purge Control Solenoid Valve
When the engine coolanl temperature is above '154'F (68'C) and the air conditioner on. the ECM controls the EVAPpurge control solenoid valve which controls vacuum to the EVAP purge control canister.
Intake Air Eypass (lAB) Control Solenoid Valve*a
When the engine rpm is below 5,750 rpm, rhe IAB control solenoid valve is activated by a signal from the ECM, intake
air flows through the long intake path, then high torque is delivered. At speeds higher than 5,750 rpm, the solenoidvalve is deactivated by the ECM, and intake air flows through the short intake path in order to reduce the resistance in
airflow.
Sell-diagnosis Function lMalfunction Indicator Lamp {MlL)lWhen an abnormality occurs in a signal from a sensor, the ECM supplies ground for the MIL and stores the code in
erasable memory. When the ignition is initially turned on, the ECM supplies ground for the N4lL tor two seconds to
check the MIL bulb condition.
Two Driving Cycle Detection Method
To prevent false indications, the Two Driving Cycle Detection Method is used for the HO2S, fuel metering-related, idle
control system, ECT sensor, TWC and EVAP control system and other self-diagnostic functions, When an abnormality
occurs, the ECM stores it in its memory. When the same abnormality recurs after the ignition switch is turned OFFand ON (ll)again, the ECM informs the driver by lighting the MlL.
However, to ease troubleshooting, this function is cancelled when you shon the service check connector. The MIL will
then blink immediately when an abnormality occurs.
4.
5.
6.
3.
4.
ECM Fail-safe/8ack.up F0nctions
1. Fail-sate Function
When an abnormality occurs in a signal from a sensor, the ECM ignores that signal and assumes a pre-programmed
value for that sensor that allows the enqine to continue to run.
2. Back-uo Function
When an abnormality occurs in the ECM itself, the fuel injectors are controlled by a back-up circuit independent of the
system in order to permit minimal driving.
11-49

I
I
It:
PGM-FI System
Engine Control Module {ECMI
,i
I
{
ili
NOTE: lf this svmotom is intermittent, check for a loose fuse No. 25 METER (7.5A) in the under_
dash fuse/relay box, a ooor connection at ECM terminal A18, or an intermittent open in the
GRN/ORN wire between the ECM (A18) and the gauge assembly.
Wire side of female terminals
I
The Mellunction Indicator Lamp(MlLl never com€3 on leven foltwo secondsl alter ignition islurn6d ON lll).
Turn the ignition switch ON (lli.
- Repair short or open in th€wire betwe€n No. 25 METER{7.5 A}fuse and gauge assem-bty.- ReDlaco No.25 METER 17.5 A)fuse.
ls the low oil pressure light on?
Try to start the engine,
Check for an open in ih6 wires
IPG lines):1. Turnthe ignition switch ON (ll).
2. Measure voltage betweenbody ground and ECM connec-tor terminals A10 and A23 indi-vidually.
Chock for an open in the wire orbulb:1. Turn the ignition sw;tch OFF.2. Connectthe ECM connector terminal 418 to body ground with
3. Turn the ignition switch ON (ll).
Repair open in the wire(slbetween ECM and G101 (located
at thermostat housingl that hadmore than 1.0 V.
ls there less than 1.0 V?
Substitute . known-good ECMand .echeck, lf symptom/indica-tion goes away, replace the origi-nalECM.
- R€pair open in the wiresb€tweon ECM {A18land gaug€
ess€mbly.- Replace the MIL bulb.
ls the MIL on?
Substitute a known-9ood ECMand rech6ck. It symptom/indica-tion goes away, repbce the origi-nal ECM.
ECM CONNECTOR A {32P)
15 16 17 18 19
r 2 3 al 15 Ga910 11
12 ,, t5 16 1tt920/22 23 2a
25 26 211184tt-MILJUMPER(GRN/ORN) I WIRE

NOTE:. Whon there is no cod6 stored, the MIL willstay on iftho aorvice check conn€ctor is snoned.' lfthis symptom is intermittent. check tor:- A loos6 Fl E/M (15 A) in the undor-hood tuse/relav box- A loose No. 13 FUEL PUMP {SRS UNIT) (15 A) in th6 under-dash fuse/retay box- An intermitt6nt short in the wir€ betwesn the ECM (C7) and th€ sorvice chock conn€qor- An intormittent open in the wire between the sorvice chsck conneclor and G40l- An intermittent short in the wire betwo€n the ECM (A18) and the gaug6 assemDry- An intermittent shon in the wir6 between the ECM (D14) and the MAP sonsor- An intermittent shon in the wire bstween the ECM (Dto), th6 Tp sensor and Fu6l tankpI6SSU16 SOnSOT- PGM-FI Main relay. See th6 OBD ll scan tool or Honda PGM Tester user's manuals for sp6cific operating instruc-!ons.
(To page 11-52)
(cont'd)
Th. M.lfunction Indic.tor LlmplMlll .t!yr on or comlr on ltt .two aaconda.
Ch.ck th! Dirgnoitic tioubl.Cod. IDTC):'1. Connoct a 6can tool or HondaPGM Tester,2. Turn tho ignition switch ON (ll).3. Read tho DTC with the scantool or Honda PGM T6st6r.
Go to trouHorhooting proQduaaa.
koo p.g6 I 1.3:ll
Ch.ct th. DTC by MIL indication:1. Turn th€ ignition switch OFF.2. Connect the SCS seNic€ con-n€ctor to the sorvico checkconnoctor,3. Turn the ignition s1\,itch ON (ll).
Rapair opan or ahort in wirabotw..n thg ECM lCSl .ndData Llnk Conncctor.Go lo troublcrhootlng pro-c.dur.3. {.co pag. 11-32)
Do.s th6 MIL indicate anv DTC?
Try to start tho engine.
Chack lor r 3hort in th. wlr.3lsqg lln.):1. Turn the ignition switch OFFand turn the ignition switchoN { },2. Disconnect th6 SCS serviceconnector,3. M€a6urg voltaOe between theECM connoctor torminal C7and body ground.
Rapah 3hort to body ground inlh. wir. b.lw..n ECM lCTl .ndacwica chack connactor.
ls ther6 approx. 5 V?
\{,
(To page 11-52)
11-51

PGM.FISystem
Gontrol Module (ECMI (cont'dlEngine
\
L
(From page 11-51)
Choc* tol s short in tho wir6 lMlLlino):1. Turn the ignition switch OFF.2. Disconn€ct the ECM conn6c-tor A (32P).
3. Turn the ignition switch ON (ll).
Repair 3hon to body ground in
rhe wire bstw.on tho ECM (A181
and MlL.
Substituto s known-good ECMend rechock. H 3ymptom/indica-tion goes awry, replacc tho origi-nelECM,
{From page 11-51)
Inspect Fl E/M (15 A) fuse in theunder-hood Iuse/relay box.
- Ropsir short in tha wircbotw.on Fl E/M {'15 Al tu3c'rnd PGM-FI m.in t.lry.- Rool.c. Fl E/M l15A)tu!€.
Inspect No. 13 FUEL PUMP (SRS
UNIT) ('l5A) fuse in the undeFdash fuse/relay box.
- Reo.ir sholt in th. wirobotw..n No. 13 FUEL PUMP
{SRs UNIT) (15 Al fur..ndFGM-FI m.in rclay.- Repl.co No. 13 FUEL PUMP(SRS UNIT) {15 Alturr.
Ch6ck for . shon in a son3or1. Turn the ignition switch ON (ll).
2. Disconnect the 3P connectorfrom oach sensor one at time:. MAP sensor. TP sensor. Fueltank pressure sensor
Rapl.cc tha 3onaor thrt cauaadihe light to 9o out.Does the MIL go OFF?
1-52
(To page 11-53)

{From page 11 52)
Chock lor a shon in lhe wi.asiVCC1. VCC2lin$l:1. Turn the ignition switch OFF-2. Disconnect the ECM connec,tor D (16P).
3. Check lor continuity betweenbody ground and ECM con-nector terminals D4 and D10individually.
- Repair short to body groundin tho wire between ECM {D4land MAP 3enso..- Rep.ir short to body groundin the wire between ECMlD10l, TP sensor and Fueltank pa6ssure sanso..
Chock lor an op€n in the wire3{lGP1.lGP2lines):1. Turn the ignition switch ON (ll).2, Measure voltage betweenbody ground and ECM connec-torterminals A'11 and A24 indi-vadually.- R6pe;r open in the wire{slbetween ECM 1A11, A24l andPGM-FI main .elay.- Check for poor connectionsor loose wi.es at the PGM-FImain relay.- Test tho PGM-FI main ral.v(see page 11-124).Check for an open in the wires(LG1, LG2line3l:1. Reconnect all sensor connec-tors.2. Reconnect the ECM connectorD (16P).
3. Turn the ignition switch ON (ll).4- M easu re voltage betweenbody ground and ECM connector terminals A9 and A22individually.
Repai. open in the wir€ls)bctween ECM {A9, A22l .ndG101 ihet had more then 1.0 V.
ls there lessthan 1.0 V?
Substitute , known-good ECMand rechock. f symptom/indica-tion goes away, roplac6 the odgi-n3l ECM.
Wire side of female terminals
ECM CONNECTOR A I32P)
a,
Wire side of female terminals
LGl
1 1-53

PGM-FI System
Intake Air Temperatute (lATl Sensor
The scan tool indicates Diagnostic Trouble Code (DTC) P0112: A low voltage (high temperature) problem in the
lntake Air Temperature (lAT) sensor circuit.
The IAT Sensor is a temperature dependant resistor (thermistor). The resistance of the thermistor decreases as the intake
air temperature increases as shown below.
RESISTANCE IKO)
THERMISTOR
l1\
\'/
rb lllo,'.u
I
1r3 2r2 2.a l.Flm roo r20 toc)
INTAKE AIR TEMPERATURE
lf the engine is warm, it will be higherthan ambient temperature.
IAT SENSOR CONNECTOR ICl2OI
- The MIL h.s b€an rooorted on.- DTC P0112 is stored.- Or lrom Probable Cau3e List.
P.oblem v6rificationi1. Turn the ignition switch ON lll).2. Check the IAT wirh the scantool.
ls 302'F (150"C) or higher (or
H Limit in Honda mode o{ thePGM Tester) or 0 V indicated?
ls the correct ambient temPerature indicated*?Roolace the IAT sensor.
Into.mittent feilur6, aystem h OKat this timc. Check to. Doot con-nections or loose wires at Cl20{lAT sensor) snd ECM.
Check tor a 3hort in the IAT sen-
1. Disconnect the IAT sensor con
2. Check the IAT with the scantool.
ls 302"F (150'C) or higher (or
H Limit in Honda mode of thePGM Tester) or 0 V indicated?Reolace the IAT sonsor.
Check for a short in the wire (lAT
line):1. Turn the ignition switch OFF.2. Disconnect the ECM connec-tor D (16P).
3. Check for continuity betweenIAT sensor connector terminalNo.2 and body ground.
Rooair short in the wirc botwoenECM {D8) .nd IAT sen3or.ls there continuity?
Substitut€ s known-good ECMand rccheck. lI normal IAT is indi-cated, replace the originel ECM.
1 1-58
Wire side of lemale terminals
L

The MIL has b€en reoorted on.DTC P0117 is stored.
Problem verification:1. Turn the ignition switch ON (ll).2. Check the ECT with the scantool.
Intermittent failure, system is OKat this time. Check for poor con-nections or looso wires at C111(ECT sensorl and ECM.
ls 302'F (150'C) or higher {orH Limit in Honda mode ofPGM Tester) or 0 V indicated?
Check tor a short in tho ECT sen-sor:1. Disconnect the ECT sensor
2. Check the ECT with the scantool.
ls 302'F (150'Ci or higher (orH-Limit in Honda mode olPGM Tester) or 0 V indicated?
Check tor s short in the wires (ECTline):r. r urn Ine rgnrtron swttch uFf,2. Disconnect the ECM connector D (16P).
3. Check lor continuity betweenECT sensor connector termi,nal No. 1 and body ground.
Check tor short in the TCM IECTlinell1, Disconnect the 22P connectorfrom the TCM.2. Check for continuity betweenECT sensor connector terminal No- 2 and body ground.
ls there continuity?
Repair shon in the wire botweenECM lD2). TCM and ECT sensor.
iT,011tl The.scan tool indicates Diagnostic Trouble Code (DTC) P0117:Alowvoltage(hightemperature) probleminthe- Engine Coolant Temperature (ECT) sensor circuit.
ECT SENSOR CONNECTOR IC111}
Wire side of fem6le terminals
Substitute a known-good ECMand recheck. lI normal ECT isindicated, replaco the origindlECM.
(cont'd)
NO
11-61

I
PGM.FI
Primary
System
Heated Oxygen Sensor (HO2S) (Sensor 1l(cont'dl
PRIMARY HO2S {Sensor'l} CONNECTOR (C1131
PHO2S T--rwHTl - --l
.l1 2ll1-{
0tls rl
Y,-I
Wire side of female terminals
Does it stay at 0.1 V or less?
Check lor a short in the wires:1. Turn the ignition switch OFF.2. Disconnect the ECM connector D (16P).
3. Check for continuity betweenHO2S connector terminal No. 1and body ground.
1 1-68
Check ror a short in the HO2S:1- Turn the ignition swilch OFF.2. Disconnect the Primary HO2S(Sensor 1) connector.3. Stan the engine and let it ;dle.4. Check the Primary HO2S (Sen
sor 1) output vohage with the
(From page '11 67i
Subslitute a known-good ECMand recheck. lf symptom/indica-tion goes away, replace lhe origi-nal ECM.