diagnostic HONDA CIVIC 1998 6.G User Guide

3.
5.
6.
1.
Fuel Cut-off Control
. During deceleration with the throttle valve closed, current to the fuel injectors is cut off to improve fuel economy at
speeds over the following rpm:. D16Y5 engine (M/T):850 rpm. D]6Y5 engine (CVT), D'16Y8 engine (USA M/T): 920 rpm
. Dl6Y8 engine (USA A,/I), D16Y7 engine (USA A,/T);910 rpm
. D16Y8 engine (Canada M/T), D16Y7 engine (canada): 990 rpm
' D16Y8 engine (Canada M/T): 1,000 rpm
. 816A2 engine: 970 rpm
. Fuel cut-off action also takes place when engine speed exceeds 6,900 rpm (D16Y5, D16Y7 engine; D'16Y8 engine:
7,000 rpm. 816A2 engine: 8.100 rpm), regardless of the position of the throttle valve, to protect the engine from
over-rewing. With '99 Dl6Y7 engine (A,/T) and '99 D16Y8 engine (A./T), the PCM cuts the fuel at engine speeds over
5,000 rpm when the vehicle is not moving.
IVC Compressor Clutch Relay
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 smooth transition to the A,/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.
Evaporative Emission (EVAP) Purge Control Solenoid Valve*a
When the engine coolant temperature above 154"F (68"C), intake air temperature above 32"F (0'C) and vehicle speed
above 0 mile (0 km/h) or [Ay'C compressor clutch on and intake air temperature above 160"F (41'C)], the ECM/PCM
controls the EVAP purge control solenoid valve which controls vacuum to the EVAP purge control canister.
Exhaust Gas Recirculation (EGR) Control Solenoid Valve*?
When EGR is required for control of oxides of nitrogen (NOx) emissions. the ECM controls the EGR control solenoid
valve which supplies regulated vacuum to the EGR valve
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.
ECM/PCM Fail-safe/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-pro-
grammed value for that sensor that allows the engine to continue to run.
2. Back-uD 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 lMalfunction Indicator Lamp (MlL)l
When an abnormality occurs in a signal from a sensor, the ECM/PCM supplies ground for the lvllL and stores the DTC
in erasable memory. When the ignition is initially turned on, the ECM/PCM supplies ground for the MIL for two sec-
onds to check the MIL bulb condition.
4. Two Trip Detection Method
To prevent false indications, the Two Trip Detection Method is used for the HO2S, fuel metering-related. idle control
system, ECT sensor, EGR system 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 0l) 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
A "Driving Cycle" consists ot starting the engine. beginning closed loop operation, and stopping the engine. lf misfir-
ing that increases emissions is detected during two consecutive driving cycles, or TWC deterioration is detected dur-
ing 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.
(cont'd)
1 1-1 05
.1.

PGM-FI System
Engine Control Module/Powertrain Control Module (ECM/PCMI
('96 - 98 Models,'99 - 00 Dl6Y5 engine with M/Tl (cont'd)
NOTE:. When there is oo Diagnostic Trouble Code (DTC) stored, the MtL wi

stay on if the SCSservace connector is connected and the ignition switch is on,. lf this symptom is intermittent, checklor:- A loose Fl E/M 115 A) fuse in the under hood luse/relay box- A loose No. 13 FUEL PUMP fuse (15 A) in the underdash fuse/relay box- An intermittent shon in the wire between the ECM/PCM (C7) and the service cnecKconnector- An intermittent short in the wire between the ECM/PCM (A18) and the gaugeassembly- An intermittent shon in the wire between the ECM/PCM {D4) and the MAp sensorAn intermittent short in the wire between the ECM/PCM (D10), the Tp sensor, theEGR valve l:ft sensor (D16Y5 engine) and/or the Fuel tank pressure sensor (,96Dl6Y8 engine (coupe), '97 016Y7 engine (coupe: KL model, sedan: KL (LX) modeli,'97 016Y8 engine {coupe: all models, sedan: KL modeti,'98,all models}- PGM-FImain relay. See the OBD ll scan tool or Honda PGM Tester user's manuals lor specitic operatinginstructions.
ECM/PCM CONNECTOR C 13lPI
Wire side of female terminals
(To page 11 109)
(To page 11,109)
11-108
The Maltunction Indicator Lamp(MlLl stays on o. comes on eftartwo s€conds,
Check the Oiagnoslic TroubleCode {DTC}I1. 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 troubleshooting p.oc€dur€s(se€ pago 11{11.Are any DTC{s) indicated?
Check the 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 (lli.
Repair opon ol short in wirebotwoen the ECM/PCM (C8)
and Data Link Connector.Go to troublelhooting proce-dure ls6e page 11-811.
Does the MIL indicate any DTC?
Try to start the engine.
Does the engine start?
Check for a short in the wire(SCS lin€l:1. Disconnect the SCS serviceconnector.2. Stop the engine and turn theignition switch ON {lli.3. Measure voltage between theECM/PCM connector terminalC7 and body ground.
Ropair short to body Iround inthe wire betweon ECM/PCM lCTland sorvice check connector.
ls there approx. 5 V?
scs tBRNI

Engine Control Module/Powertrain Control Module (ECM/PCM)
('95 - 00 Models except Dl6Y5 engine with M/T)
NOTE:. When there is no Diagnostic Trouble Code lDTC) stored, the MIL will staY on if the SCS
seruice connector is connected and the ignition switch is on.. lf this symptom is intermittent, check for:- A loose No. 25 (METER) {7.5 A) fuse in the underdash fuse/relay box- A loose Fl E/M (15 Alluse in the undeFhood fuse/relay box- A loose No. 13 FUEL PUMPfuse (15 A) in the under-dash fuse/relay box- An intermittent shon in the wire between the ECM/PCM (A18) and the gauge assem'
- an intermittent short in the wire between the ECM/PCM (C19) and the MAP sensor- An intermittent short in the wire between the ECM/PCM {C28), the TP sensor, the
EGR valve lift sensor (D16Y5 engine) and/or the Fuel tank pressure sensor ('96 D16Y8
engine (coupe),'97 D16Y7 engine lcoupe: KL model, sodan: KL (LX) model)"g7
Dt6Y8 engine (coupe: all mod;ls, sedanl KL model),'98-all models,'99-al' models''00-all models.- PGM'FI main relay. See the oBD ll scan tool or Honda PGM Tester user's manuals for specific operating
instructrons,
ECM,/PCM CONNECTOR A I32PI
Wire side of {emale terminals
The Mrlfunction Indicator LamP{MlL) never comes on {even tor
two seconds) after ignition is
turned ON lll).
Turn the ignition switch ON lll).
- Repair shott or open in thowire bstwoon No. 25 IMETER)l?.5 A)tuse and gauga tsom_blv.- Reolace No. 25 (METERI (7.5
Alluse.
ls the low oil pressure light on?
Try to start the engine.
Check for an opon in the wire orbulb (MlL line):1. Turn the ignition switch OFF.2. Connect the ECM/PCM con'
nector terminal A18 to bodyground with a iumper wire.
3. Turn the ignition switch ON (ll)
Does the engine start?
- Repair open in tho wire3
betwoon ECM/PCM (A18) andgaugo .*tembly.- Rool.ce the MIL bulb.
Substitute a known-good ECM/
PCM and rochoc&. lf sYmptom/indication goes sw6y, repl.ce
tho original ECM/PCM.Turn the ignition switch OFF.Inspect Fl E/M (15 A)fuse in theunderhood Iuse/relay box.
Rop.ir short in the wirc
betwo€n Fl E/M (15 A) luso
and PGM-Fl mrin rGl.y.Reol.ce Fl E/M (15 A)tusa.
lnspect No. 13 FUEL PUMP {15 A}
luse in the under-dash fuse/relay
- Reoair short in the wiro
between No. 13 FUEL PUMP
115 Al luse sod PGM-FI mainrelay.- Reolace No. 13 FUEL PUMP115 A) tuse.
(To page 11 112)
(cont'd)
11-111
.f,

NOTE:"in-"n tf'"r" is no Diagnostic Trouble Code (DTCi stored, the MIL will stav on ;{ the scs
service 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 check
connector- An intermittent short in the wire between the ECM/PCM (A181 and the gauge
. s"" it'" Oab ll scan tool or Honda PGM Tester user's manuals for specific operating
instructions.
'l
ECM/PCM CONNECTOR A I32P)
Wire side of female terminals
The Malfunction Indicator LamP
lMlL) staYs on or comes on after
Check the Diagnostic Trouble
Code (DTC):
1. Connect a scan tool or Honcla
PGM Tester.
2. Turn the ignition switch ON (ll)
3. Read the DTC with the scan
tool or Honda PGM Tester.
Go to troubloshooting Proc€dures(see page 1141).Are any DTC(S) indicated?
check the DTC by MIL indic.tion:
1. Turn the ignition switch OFF
2. Connect the SCS service con_
nector to the service check
3. Turn the ignition switch ON (ll)
Repair open or 3hort in wiro
between ihe ECM/PCM (A21)
and Data Link Connector.
Go to troubleshooting Ploce_du.es (see page 11-811.
Does the MIL indicate anY DTC?
Try to start the engine
Substitute . known-good ECM/
PCM and recheck lt sYmptom/
indication goes awaY, rePlaca
th. original ECM,/PCM.
Check for a short in the wi.e(Scs line):1. Turn the ignition switch OFF
and turn the ignition switch
oN 1 ).2- Meas u re voltage between
body ground and the ECM/
PCM connector terminal A10
Reoair short to body ground in
the wiro bstwaen ECM/PCM (A101
and service ch€ck connoctot.ls there battery voltage?
(To page 11-'114)
(cont'd)
1 1-1 13

Manifold Absolute Pressure (MAP) Sensor ('96 Models)
The scan tool indicates Diagnostic Trouble Code (DTC) P0106: A mechanical problem (vacuum leak) in the
Manifold Absolute Pressure (MAP) Sensor system'
TheMAPsensorconvertsmanifoIdabsoIutepressureintoeiectricaIsigna|sandinpUtstheEcM/PcM'
OUTPUTVOLTAGE
(v13.5
3.0
2.5
2.0
1.5
1.0
0.5
0lin. Hgl GAUGE
- The MIL has been reported on- OTC P0106 is storod.- Or from Ptobable Cause Lisl.
Problom verificetion:1. Do the ECM/PCM Reset Pro-
cedure.2. Start the engine and keep
engine speed at 1,000 rpm for
one minute with the transmis'
sion in @ or I Position {Mff
in neutral).
ls DTC P0106 indicated?
Check tor vacuum leakage or
blockage between the MAP sen'
sor and throftle bodyCheck the MAP sensor outPut:
1. Turn the ignition switch OFF
2. Turn the ignition switch ON (ll).
3. Check the MAP with the scan
tool.ls there leakage or blockage?
Chock the MAP s€nsol output:
1. Stop the engane.2. Turn the ignition switch ON (ll).
3. Check the MAP with the scan
tool.
READING300(mm Hgl
(To page 11 116)
{cont'd)ll,(To page 11-116)
1 1-1 15

Manifold Absolute Pressure {MAP} Sensor
('96 - 98 Models,'99 - 00 D16Y5 engine with M/T)
I
The scan tool indicates Diagnostic Trouble Code (DTC) PO107: A low voltage (high vacuum) problem in the
Manifold Absolute Pressure (MAP) sensor.
MAP SENSOR 3P CONNECTOR (C111)
vccr(YEL/BEDI
Wire side of female terminals
(D16Y5 engine (with
cw))T
YES
(cont'd)
11-117
Tho MIL has been roport€d on.
DTC P0107 is storod.
Problam verification:1. Turn the ignition switch ON (ll).
2. Check the MAP with the scan
lool.
lntormittont failuro, sYatgm ia OK
al thb timo. Chock lor Pool con_
noqtiona or looso wirca at C111
{MAP !6nsor) ond ECM/PCM.
ls approx. 101 kPa (760 mmHg,
30 in.Hg) indicated?
Chock for an opon in wiJe (VCCI
lino):1. Turn the ignition switch OFF.
2. Disconnect the MAP sensor
3. Turn the ignition switch ON (ll).
4. Measure voltage between the
MAP sensor connector No l
terminal and No 2 terminal
Ropair open in tho wit b€twocn
ECM/PCM (Dill tnd MAP !enso].ls there approx. 5 V?
Check for .n open or ahort in the
MAP 3€naor:Check the MAP with the scan
tool.
ls approx. 2 kPa (15 mmHg,
0.6 in.Hg) or less indicated?
Chsck to. a short in the TCM:
1. Turn the ignition switch OFF.
2. Disconnect the 22P connectorfrom the TCM.3. Turn the ignition switch ON
0r).4. check the MAP with the scan
tool.
(To page 11-118)

PGM-FI System
Manifold Absolute Pressure (MAPI Sensor
11-122
('99 - 00 Models except D16YS engine with M/T) (contd)
The scan tool indicates Diagnostic Trouble Code (DTC) P0108: A high voltage flow vacuum) problem in theManifold Absolute Pfessure (MAp) sensor,
MAP SENSOR 3P CONNECTOR (C111I
MAPIRED/GRNI
Wire side of female terminals
vcclIYEL/RED)
ECM/PCM CONNECTOR C (31PI
JUMPER WIRE
Wire side of female terminals
Tho MIL has boon rcDortod on.DTC ml 08 b stolod.
Problem verification:'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 scantoot,
Intormittent f.ilu.e, rystom is OXat thi! time. Chock tor poor con-n6ction3 or looso wirea at C111(MAP 3en.or) and tho ECM/PC-M.
ls 101 kPa (760 mmHg.30in.Hg) or higher indicated?
Check for an open in the MAPaon5('r:1. Turn the ignalion switch OFF.2. Disconnect the MAP sensor3P connector.3. Install a jumper wire betwesnthe MAP sensor 3P conn6ctorterminals No.3 and No.2.4. Turn the ignition switch ON {ll).5. Check the MAP with the scantool.
ls 101 kPa (760 mmHg, 30in.Hg) or higher indicated?
Check fo. an opcn in wiro (SGlline):1. Removo the jumper wire.2. Measure voltage between theMAP sonsor 3P connector terminals No. 1 and No.2.
Roprir opon in tha wiJo bctwoenthc ECM/FCM (C7l rnd the MApsonln t.
ls there approx. 5 V?
Chsck for an open in tho wi.e{MAP lino}:1. Turn the ignition switch OFF.2. Install a jumper wire on theECM/PCM connectors betweenC7 and C17.3. Turn the ignition switch ON (ll).4. Check the MAP with the scantool,
Repair op€n in the wir6a bstwoontho ECM/FCM (C171 and rh6 MApscnltoa.
ls 101 kPa (760 mmHg, 30in.Hg) or higher indicated?
Substituto a known-good ECM/PCM and rechcck, It normal MAPis indiceted. r.place tho originalECM/PCM.
JUMPER WIRE
--

L
Manifold Absolute Pressure (MAP) Sensor (cont'dl
The scan tool indicates Diagnostic Trouble code (DTc) P1128: Manifold Absolute Pressure (MAP) lower than
exoected.
The scan tool indicates Diagnostic Trouble code (DTC) P1129: Manifold Absolute Pressure {MAP) higher than
exoected,
- Tho MIL has been t€Ported on.- DTC P1128 is stored.
Problem verification:1. Turn the ignition switch ON (ll).
2. Check the MAP with the scan
tool.
lntermitteni failu.e, sYstom i! OK
at thb time.ls 54.1 kPa (406 mm Hg, 16.0
in. Hg) or higher indicated?
- The MIL has been roported on.- DTC P1129 is slorod
Problem v6rilicaiion:1. Start the engine. Hold the
engine at 3,000 rpm with no
load (in Park or neutral) until
the radiator fan comes on,
then let it idle.
2. Check the MAP with the scan
tool.
Int6rmittent failuto, sy3tem i3 OK
at thi3 time.ls 43.3 kPa (325 mm Hg, 12 8
in. Hg)or less indicated?
11-123

PGM-FI System
Intake Air Temperature (lAT) Sensor ('96 - 97 Models)
The scan tool indicates Diagnostic Trouble code (DTC) P0111: A range/performance problem in the lntake AarTemperature (lAT) Sensor circuit.
The IAT sensor is a temperature dependant resistor (thermistor). The resistance of the thermistor decreases as the intakeair temperature increases as shown below.
RES|STAI{CE {tol
. 32 .. ro. tr. 2r, zaa r..l-20 o 20 /|o ao ao 100 rrotlcl
INTAIG AIR TEMPEMTURE
- The MIL hss beon reported on.- DTC P0111 is stored.- Or from Probable C.use List.
Problem verification:1. Turn the ignition switch OFF.2. Disconnect the IAT sensor 2Pconnector,3. Remove the IAT sensor.4. Reconnect the IAT sensor 2p
5. Leave the IAT sensor exposedto ambaent temperature,6. Turn the ignition switch oN fll).7. Check the IAT with the scantool.
Rsplscg the IAT sensor.
Check tho IAT sensor output:1. Warm the IAT sensor with ahair dryer-2. Check the IAT with the scantool.
Did the IAT rise 2"F (1.C) or morefrom the ambient temperature?Int€rmittont failu.e, system is OKat this time.
Replsce the IAT sensor.
11-124

IIntake Air Temperature (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.
RESISTANCE IKOI
.-l
*2: lf the engine is warm, it will be
higher than ambient temPerature.
IAT SENSOR 2P CONNECTOR {C112)
. a2 .. toa rra rrl l:rt t.al20 0 20 ro ao ao too t2ot.cl
INTAXIE AIR TEMPEFATURE
IAT{RED/YEL)
termrnars
-+-r
I'l'l-_T-
I=
Wire side of female
The MIL has been Teported on.
DTC P0112 is stored.
Problem verification:1. Turnthe ignition switch ON 1ll)2. Check the IAT with the scan
tool-
ls 302'F (150"C) or hagher (or
H Limit in Honda mode ot
PGM Tester) or 0 V indicated?
ls the correct ambrent temper
ature indicatedi'?Roolac€ tho IAT 3ensor.
lntermittent failure, svstom is OK
6t this tim€. Check for Poor Gon-
nections or loos€ wires st C112
{lAT.en3orl and ECM/PCM.
Check tor a shon in the IAT sen-
sor:1. Disconnect the IAT sensor con
nector.2. Check the IAT with the scan
tool.
ls 302"F (150'C)or higher (or
H'Limit in Honda mode of
PGM Tester) or 0 V indicated?
Ch6ck for s short in the wira (lAT
lin€):1. Turn the ignition switch OFF
2. Disconnect the ECM/PCM con-
nector D (16P) (C (31P))*'.
3. Check for continuity between
the IAT sensor 2P connector ler-
minal No. 2 and body ground.
Reoair short in the wire bstweenECM/PCM tD8 (c25)'1) and IAT
Substitute a known-good ECM/
PCM and recheck. It normel IAT
is indicated, replace the original
ECM/PCM.
* l: '99 - 0O models except Dl6Y5 engine with M/T-rf,
11-125