1997 HONDA CIVIC radiator fan circuit

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.

I
Throttle Position (TP) Sensor ('99 - 00 Models except D16Y5 engine with M/Tl
The scan tool indicates Diagnostic Trouble Code {DTC) P0123: A high voltage problem in the Throftle Position
{TP) sensor circuit.
TP SENSOR 3P CONNECTOR {C11OI
sG2{GRN/BLKIvoc2
{YEUBLU}
'l'Wire side of female term;nals
ECM/PCM CONNECTOR C (31PI
Wire side of femal€ terminals
(cont'd)
11-137
The MIL has been reported on
DTC P0123 is slored.
Problem verification: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 turn the ignition swatch
OFF,2. Turn the;gnition switch ON (ll).
3. Check the throttle Positionwith the scan tool.
lntormittenl tailure, 3ystom is OK
at this time. Check tor Poor con'
neqtions or loo3€ wires at C'110(TP sensorl tnd ECM/PCM.
ls there approx. 10% when the
throttle is fully closed and
approx. 90% when the throttleis fully opened?
Ch€ck for an open in the TP s6n-
soJ:1. Turn the ignition switch OFF.
2. Disconnect the TP sensor 3P
3. Turn the ignition switch ON (ll).
4. At the wire harness side, mea-
sure voltage between the TP
sensor 3P connector terminalsNo. 1 and No.3.
ls there approx. 5 V?
Check tor an open in the wire(SG2lino):
Measure voltage between ECM/
PCM connector C (31Pi terminals
C18 and C28.
Repair open in the wite betwe€nECM/PCM (Cl81and TP son.or.ls there approx. 5 V?
Substitute a known-good ECM/PCM and recheck. lf Pr$cribedvoltage is now aveilabl6. replacethe original ECM/PCM.

Primary Heated Oxygen Sensor {Primary HO2SI (Sensor 1)
t('96 - 98 Models except Dl6Y5 engine with M/Tl
The Heated Oxygen Sensor (HO2S) detects the oxygen content in the exhaust gas and signals the ECM/PCM. In operation,
the ECM/PCM receives the sjgnals from the sensor and varies the duration during which fuel is injected To stabilize the
sensor,s output, the sensor has an internal heater. The Primary HO2S (Sensor 1) is installed in the exhaust manifold.
HO2S:
VOLTAGE {VI
The scan tool indicates Diagnostic Trouble Code (DTC) P0131; A low voltage
Oxygen Sensor (H02S) (Sensor 1) circuit.
R|cH-AIR- - LEANFUELRANO
problem in the Primary Heated
SENSOR
ztRcoNlA
The MIL has be€n teported on.DTC P0131 is siorcd.
Problom verificalion:1. Do the ECM/PCM Reset Pro'
cedure.2. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neutral) untilthe radiator fan comes on,3. Test-drive with the A/T in Eposition (M/T in 4th gear)
4. Check the Primary HO2S(Sensor 1) output voltage with
the scan tool during accelera-
tion using wide open throttle.
lntcrmift€nt failura, 3Y3tem is OKat this tims. Check for Poor con-nections or loo3e wi.o3 at C123(Primlry HO2S, 3sn3or 1) and
ECM/PCM,
(To page 1I-140)
{cont'd)
1 1-139

Primary Heated Oxygen Sensor (Primary- Fjq?S) (Sensor 1l
('99 - 0b Models exiept D16Y5 engine with M/T)
TheHeatedoxygensensors(Ho2S)detecttheoxygencontentintheexhaustgasandsigna|stheEcM/PcM'|noperation,
the EcM/pcM receives the signars from the sensor and varies the duration during which fuel is injected. To stabilize the
sensor,soutput,thesensornasaninternaIheater.ThePrimaryHo2S(sensorl)isinsta|ledinexhaustmanifo|d(D16Y8.
81642 engine: exhaust PiPe A)
SENSORTERMINALSVOLTAG€ (VI
HEATERTERMINALS
The scan tool indicates Diagnostic Trouble Code (DTC) P0131: A low voltage
Oxygen Sensor (HO2S) (Sensor 1) circuit
RICH+ AIR- - LEANFUELRATIO
problem in the Primary Heated
HEATER
- The MIL has been t€Ported on.- DTC P013'l is stored.
Problem veritication:1. Do the ECM/PCM Reset Pro-
2. Start the engine. Hold the
engine at 3,000 rpm wrth no
load (in Park or neutral) until
the radiator fan comes on
3. Check the PrimarY HO2S
lSensor 1) output voltage wath
the scan tool during accelera
tion using wide open throttle
lntermittont f.ilure, 3ystem i3 OK
at thi3 time. Check tor Poor con'
nections or loose wires el C123
{Primary HO2S, Sensor 1) and
ECM/PCM.
Does the voltage stay at 0 5 v
or less?
Check the fuel pressLlre (see Page11,109).
(To page 11 142)(cont'd)
11-141

Primary Heated Oxygen Sensor (Primary HO2SI (Sensor 1)
('96 - 9b Models except Dl6Y5 engine with M/Tl
PHO29IWHT}
The scan tool indicates Diagnostic Trouble Code (DTC) P0132: A high voltage problem in the Primary Heated
Oxygen Sensor (Primary H02S) (Sensor'l) circuit.
PRIMARY HO2S (Sonso. 'll 4P CONNECToR
tc123t
sG2IGRN/BLKI
Wire side ot female terminals
ECM/PCM CONNECTOR D I16PI
JUMPER WIRE
PHO2S (WHT}SG2 IGRN/BLKI
Wire side of tem6le terminals
Probl€m verification:1. Do the ECM/PCM Reset Pro-
cedure.2. Start the engine. Hold the
engine at 3,000 rpm with no
load (in Park or neutral) until
the radiator fan comes on
3. Test-drive with the A/T in Eposition (M/T in 4th gear)
4. Check the PrimarY HO2S(Sensor 1) oLltPut voltage with
the scan tool during decelera'tion using completely closed
throttle.
Int.rmittont fiilur., system it OK
at thb timo. Chock for Poot con-
nections or loo3a wir63 at Cl23
lPrimarY HO2S, SensoJ 1l .nd
ECM/PCM.
Does the voltage stay at 1.0 V
or more?
Check for an open in the Primary
HO2S:1. Turn the ignition switch OFF.
2. Disconnect the Primary HO2S(Sensor 1) 4P connector'
3. Connect the PrimarY HO25
lSensor l) 4P connector termi-
nals No. 1 and No. 2 with a
4. Turn the ignition switch ON (ll).
5. Check the PrimarY H02S(Sensor 1i outPut voltage with
the scan tool.
lsthere 1.0 V or more?
Check for an open in the wiro
{PHO2S line):1. Turn the ignition switch OFF.
2. Connect EcM/PcM connector
terminals D7 and D11 with ajumper wrre,3. Turn the ignition switch ON lll)4. Check the PrimarY HO2S(Sensor 1) output voltage withthe scan tool,
Replir open in tho wirc b€twccnECM/PCM lo?) and Prim!.Y
HO2S lsonsor 1).ls there 1.0 V or more?
Substitute a known-good ECM/PCM and recheck. lf 3ymptom/indicetion goos awey, roplacethe oliginal ECM/PCM.
11-143

PGM-FI System
Primary Heated Oxygen Sensor (Primary HO2SI (Sensor 1)
('99 - 00 Models except D16Y5 engine with M/T)
The scan tool indicates Diagnostic Trouble Code (DTC) P0132: A high voltage problem in the primary HeatedOxygen Sensor (Primary HO2S) {Sensor I ) circuit.
PRIMARY HO2S ls€n3or 1' 4PCONNECTOR(c123t
PHO2SIWHTI
Wire side of temale terminals
ECM/PCM CONNECTOR C 131PI
sG2(GRN/
BLK)
SG2 IGRN/8LK}
Ware side of female terminals
The MIL has been reported on.OTCP0132 is stored.
Problem vorificalion:1. Do the ECM/PCM Reset Procedure,Start the engine. Hold theengane at 3,000 rpm with noload (in Park or neutral) untilthe radiator fan comes on.Check the Primary HO25{Sensor lioutput voltage withthe scan tool during decelera-taon using completely closedthrottle.
Intermittent tailure, systom k OKat this time. Chock tor poor con-nections or looso wir* at Cl23(Primaly HO2S, Sonsor 1) andECM/PCM.
Check lor an open in the PrimaryH02S:1. Turn the ignition switch OFF.2. Disconnect the Primary HO2SlSensor 1)connector.3. Connect the Primary H02S(Sensor 1)4P connector terminals No. 1 and No. 2 with a
4. Turn the ignition switch ON (ll).5. Check the Primary H02S{Sensor l) output voltage withthe scan tool.
ls there 1.5 V or more?
Check lor an open in th€ wire(PHO25 lin€l:1. Turn the ignition switch OFF.2. Connect ECM/PCM connectorterminals C16 and C18 with ajumper wire.3. Turn the ignition switch ON {lli.4. Check the Primary HO2S(Sensor 1i output voltage withthe scan tool,
Roptir op.n in tho wire betweonECM/PCM lCl6l and Prim.ryHO2S lsensor 11.
ls there 1.5 V or more?
Subsiitute a known-good ECM/PCM and r.check. lf symptom/indication goos away, replecethe original ECM/PCM.
11-144

Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1l
The scan tool indicates Diagnostic Trouble Code (DTC) P0133: A slow response problem in the Primary Heated
Oxygen Sensor {Primary H02S) (Sensor 1) circuit.
The scan tool indicates Diagnostic Trouble code (DTC) Pl163: A slow response problem in the Primary Heated
Oxygen Sensor (Primary HO2S) (Sensor 1)circuit
Description
By controlling the airlfuel ratio with a Primary Ho2S {Sensor 1) and a secondary HO2S {Sensor 2), the deterioration of the
primary HO2S (Sensor 1) can be evaluated by its feedback period. when the feedback period of the Ho2s exceeds a cer-
tain value during stable driving conditions, the sensor will be judged as deteriorated
when deterioration has been detected during two consecutive trips. the MIL comes on and DTC P0133 or P1163* will be stored'
NOTE: tf DTC P0131, P0132 and/or P0135 are stored at the same time as DTC P0133, troubleshoot those DTCS first' then
troubleshoot DTC P0133. lf DTC Pl 162, P1168 and/or P1169 are stored at the same time as DTC P1163, troubleshoot those
DTCS first, then recheck for DTC Pl163.
Possible Cause
o Primary HO2S (Sensor 'l) Deterioration
o Primary HO2S Heater (Sensor 1)Deterioration
. Exhaust system leakage
Troublsshooting Flowchart
tFol3al
I P1163
- The MIL has been reported on- DTC P0133 and/or Pl163* is
stored,
Problem Verilication:1. Do the ECM/PCM Reset Pro
cedure-2. Connect the scan tool
3. Start the engine. Hold the
engine at 3,000 rpm with no
load (in Park or neutral) until
the radiator fan comes on
4. Connect the SCS service con-
nector.5. Test-drive u nder Iollowing
conditions.- 55 mph (88 km/h) steadyspeed- A/f in D position {M/T in
5th gear)
Until readiness code comes
lntermittent failure, 3Y3tem i3 OK
at thi3 time. Ch.ck lol Poor con-
ncctions or loosc wiros at C123
{C145)! lPrimary HO2S, Sensor 1l
and ECM/PCM.
Replace th6 Prim.ry HO2S (Sen'
sor 11.
*: P'l163 (D16Y5 engine with M/T)
11-145

PGM-FI System
l:in1.".fy Heated Oxygen Sensor (primary HO2SI (sensor 1l(D16Y5 engine with M/D (cont'd)
The scan toor indicates Diagnosti" -Tl:y|* code (DTC) pl164: A range/performance probrem in the primaryHeated Oxygen Sensor (primary HO2S) (Sensor 1)circuit.
The scan tool indicates Diagnostic Trouble Code (DTC) p1165: AHeated Oxygen Sensor (primary HO2S) (sensor 1) circuit.
range/performance problem the pnmarv
The MIL has beon reponed on.DTC P1164 is stored.
Problem Verilication:1. Do the ECM Beset Procedure.2. Start the engine. Hold theengine at 3,000 rpm with noload (transmission in neutral)untilthe radiatorfan comes on.3. Connect the SCS service con-nector.4. Test-drive in 4th gear. Startingat 1,600 rpm, accelerate usingwide open throttle for at least 5seconds. Then decelerate tor atleast 5 seconds with the throttle completely closed.
Intgrmittent failure, syrtem b OKat this time. Check tor Door con-noctions or loose wires at C1a5(Primary HO2S. Senso.

andECM.
ls DTC Pl164 indicatedT
- The MIL has been reoorted on.- DTC P1165 is stored.
Intermittent l.iluro, system b OKat lhis time. Ch€ck tor poor con-noctions or loose wir6 at Ci45(Prioary HO2S, Sen3or 1l .ndECM.
ls DTC P1165 indicated?
Replace the P.imary HO2S (S6n-sor 11.
Problem Vo.ification:1. Do the ECM Reset Procedlre.2. Start the engine. Hotd theengine at 3,000 rpm with noload (transmission in neutral)until the radiator fan comes
3. Connect the SCS service con,nector.4. Test-drive u nder followingconditions.- 55 mph steady speedTransmission in 5th gearUntil readiness code comes
1 1-150