1996 HONDA CIVIC idle sensor

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.

!Manifold Absolute Pressure (MAPI Sensor -
i;idlga lil;dels,'99 - 00 Dl6Y5 ensine with M/T)
ll
The scan tool indicates Diagnostrc Trouble code (DTC) Po108: A high voltage (low vacuum) problem in the
Manifold Absolute Pressure (MAP) sensor.
MAP SENSOR 3P CONNECTOR ICl11}
MAPIRED/GRNI
JUMPER WIRE
Wire side ol female terminals
vcclIYEL/RED)
ECM/PCM CONNECTOR D (16PI
MAP(RED/GRN)
sG1(GRN/WHT)
Wire side of female terminals
(cont'd)
11-121
The MIL has been reported on
OTC m108 is stolod.
Problem vetitication:
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.
lntormittent lailure, sFtom k OK
.t thb time. Chock lor Poor con'
nections or loorg wires at Cll'l
|MAP sensorl snd ECM/PCM.
ls 101 kPa (760 mmHg,30 0 in.Hg)
or higher indicated?
Check tor an open in the MAP
36nSOt:1. Turn the ignition switch OFF
2. Disconnect the MAP sensor
3P connector.3. Install a jumper wire betlveen
the MAP sensor 3P connector
terminals No 3and No 2.
4. Turn the ignition switch ON (ll).
5. Check the MAP with the scan
tool.
ls 101 kPa (760 mmHg, 30 0 in.Hg)
or higher indicated?
Check for an open in wire (SG1
line):1. Remove the iumper wire.
2. Measure voltage between the
MAP sensor 3P connector te.
minals No. 1 and No 2
Rapai. open in the wito batwoen
ECM/PCM (D12) .nd MAP !en.or.ls there approx. 5 V?
Check for an oPon in the wiie
(MAP linel:1. Turn the ignition switch OFF.
2. Connect the ECM/PCM con-
nector terminals D3 and D12
with a iumPer wire.
3. Turn the ignition switch ON (ll).
4. Check the MAP with the scan
tool.
Repair opon in the wiles bstlt oon
ECM/PCM (D3l and MAP 3oGor.ls 101 kPa (760 mmHg, 30 0 in.Hg)
or higher indicated?
Substituto a known'good ECM/
PCM and rochock. ll normal MAP
is indicated, replace tho original
ECM/PCM.
JUMPER WIRE
lr,

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
Engine Coolant Temperature (ECTI Sensor
The scan tool indicates Diagnostic Trouble code (DTC) P0116; A range/performance problem in the EngrneCoolant Temperature (ECT) Sensor circuit.
The ECT Sensor is a temperature dependant resistor (thermistor). The resistance of the thermistor decreases as the enginecoolant temperature increases as shown oetow.
RESISTANCE(ko)
NOTE: lf DTC P0117 and/or P01'18 are stored at the same time as DTCfor DTC P0116.
Possible Cause
. ECT sensor deterioration. Malfunction in the thermostat and cooling system
Troubleshooting Flowchart
-a 32 68 r0a la0l?6 2t2 2481'rr-20 o 20 ao o D r@ Il, r'c)
ENGINE COOLANT IEMPERATURE
P0116, troubleshoot those DTCS first. then recheck
11-128
THERMISTOR
- The MIL has bogn reported on.- DTC P0116 is stored.
Problem verification:1. Start the engine. Hotd 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 the
Intermiftent lailure. system is OKai thi. time. Ch.ck the thc.mo-stat 6nd thc cooling system.
is 176 200'F {80 - 93'C)or0.0-0.TVindicated?
Check the thermostat and thecooling system. ll they als OK,raplace the ECT sensor.

PGM-FI System
(From page 11-139)
Check for a shon in the HO2S:1. Turn the ignition switch OFF.2. Disconnect the Primary HO2S(Sensor 1) 4P connector.3. Start the engine and let it idle.4. Check the Primary HO2S(Sensor 1)output voltage withthe scan tool,
Does it stay at 0.1 V or less?
Check for a short in lhe wire(PHO2S linel:1. Turn the ignition switch OFF.2. Disconnect the ECM/PCM con-nector D ('l6P).
3. Check for continuity betweenthe Primary HO2S lsensor 1)4P connector terminal No. 1and body ground.
Repair short in lhe wire b6tw6enECM/rcM (D7) and Primary llO2S{Sensor 1}.
Substitute a known-good ECM/PCM and recheck. ll symptom/indication goes awry, replaco theoriginal ECM/PCM.
Primary Heated Oxygen Sensor (Primary HO2S) (sensor 1l
('96 - 98 Models except Dl6Y5 engine with M/T) (cont'dl
PRIMARY HO2S lsonsor 1l ,tP CONNECTOR lC123l
Wire side of female terminals
11-140

PGM-FI System
Primary Heated Oxygen Sensor (Primary HO2SI (Sensor 1)
('99 - 00 Models except Dl6Y5 engine with M/T) (cont'd)
PRIMARY HO2S {S€oror 1} 4P CONNECTOR lc123l
PHO2S f----l,wHl_l:-f;-l
0ffi
_L
Wire side of female terminals
(From page 11 141)
Chock fo. a shori in the HO2S:1. Turn the ignition switch OFF.2. Disconnect the Primary HO2S(Sensor 1i 4P connector.3. Stan the engine and let it idle.4. Check the Primary HO2S(Sensor 1) output voltage withthe scan tool.
Does it stay at 0.5 V or less?Roplaco the HO2S (Sensor 1).
Check tor a short in the wire{PHO2S linel:1. Turn the ignition switch OFF.2. Disconnect the EcltI/PcM con-nector C {31P).3. Check for continuity betweenthe Primary HO2S lsensor 1)4P connector terminal No. 1and body ground.
ReDair shorl in the wi.e betweenECM/PCM (Cl61 and PrimaryHO2S (Sercor 11.
Substitute a known-good ECM/PCM and recheck. lf symptom/indication goes away, replace theoriginal ECM/PCM.
11-142

PGM-FI System
Primary Heated Oxygen Sensor (Primary HO2SI (sensor l)
(Dl6Y5 engine with M/T) (cont'd)
(From page 1l-147)(From page 11 147)
(To page 11 149)
{GRN/BLK}
(GRN/8I-K}
(To page 11-149)
11-148
Substitute a known-good ECMand rechock. tf symptom/indicr-tion goes away, replace the origi-nalECM.
Check for a short in the wire llP+lin6):1. Disconnect the 8P connectorIrom the Primary HO2S (Sen-
sor 1).2. Check tor continuity betweenbody ground and ECM connec-tor terminal C25.
Repair short in the wiro botweenthe Primarv HO2S {Sensor 1} andECM {C25}.
Replace th€ Primary HOzS {Sen-sor 11.
| 2 3ra1a9to
tl 12t516111a
p ffi;r, w''.""i0"or.I lemate lerml
ls there more than 5.0 V?check the EcM:1. Turn the ignition switch OFF.2. Disconnect the 8P connectorfrom the Primary HO2S (Sen-
sor 1).3. Turn the ignition switch ON (ll).4. Measure voltage between ECN4connector C25 and D11.
ls there more than 5.0 V?
Check the ECM input voltage llP-/vS-linel:1. Start the engine. Hold theengine at 3,000 rpm with noload (transmission in neutral)untilthe radiator fan comes on,then let it idle.2. Measure voltage between ECMconnector terminals C24 andDt1.
Subslitute a known-good ECMand rgcheck. It symptom/indica-tion goes away, repl.ce the origi-nal ECM.
ls there 2.6 2.8 V?Check th6 ECM output voltage(VS+ linel:Measure voltage between ECMconnector terminals C25 and D11.
7a9t0It 12t3t6'11ta
VS+{WHT}sG2
235
,9 ,101l12
l3'tat515
1 2i35a9t0't2'ttt5ttrl22
VS+{WHT)sG2
23
6lt9ll1315