1997 HONDA CR-V Sensor exhaust

22. Remove the radiator caP.
!@ use care when removing the radiatol
cap to avoid scalding by hot coolani or steam.
23. Raise the hoist to full height
24. Remove the front tires/wheels.
25. Remove the guard bar and splash shield.
8 x 1.25 mm2,1 N.m {2.4 kgf,m, 17 lbl ft)6x1.0mm9.8 N.m {1.0 kgf.m, GUARD BAR7.2 tbf.rr)
Loosen the drain plug in the radiator. Drain the
engine coolant (see page 10-51.
Drain the transmission oil or fluid. Reinstall the drain
plug using a new washer lsee section 13 (M/T) or sec-
tion 14 (ly'T)].
Drain the engine oil. Reinstall the drain bolt using a
new washer {see page 8-4).
Bemove the A,/C compressor. Do not disconnect the
!y'C hoses.
SPLASH
26.
27.
28.
29.
ER
lCEB
30. Disconnect the primary heated oxygen sensor (prl-
mary HO2S) connector. then remove exhaust pipe A
'97 - 98 U.S. models (Cslifornia):
PRIMARY HO2SCONNECTOR
GASKETReplace.
SELF-LOCKING NUT8 x 1.25 mm22 N.m 12.2 kgf.m,16 lbf.ftlReplace.
8 x 1.25 mm16 N.m {1.6 kgf.m.12 tbt.ftlReplace.
SELF.LOCKING NUT10 x 1.25 mm54 N.m 15.5 kgf.m,.() tbf.frlReplace.
NUT
'97 - 98 U.S. mod€ls {Except California):'99 - 00 models:
PRIMARY HO2SCONNECTORGASKETSReplace.
GASKETReplace.
SELF.LOCKING8 x 'l.25 mm22 N.m (2.2 kgf m,
16 rbf.ftlReplace.
SELF.LOCKING NUT
8 x 1.25 mm16 N.m 11.6 kgf.m,12 tbt fr)Replace.
10 x 1.25 mm54 N.m 15.5 kgt.m,40 rbt.ftlReplace.
{cont'd)
5-7
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ECM/PCM Data
By connecting the OBD ll scan tool or the Honda PGM Tester to the 16P data link connector (OLC), various data can be
retrieved from the ECM/PCM. The items listed in the table below conform to the SAE recommended practice
The Honda PGM Tester also reads data beyond that recommended by SAE.
understanding this data will help to find the causes of intermittent failures or engine problems.
NOTE:
The ',operating values" given below are approximate values and may be different depending on the environment and
the individual vehicle.
Unless noted otherwise. "at idle speed" means idling with the engine completely warmed up, transmission in position
Park or neutral and the A,./C and all accessories turned otf.
DataDesc.iptionOp€rating ValuoFreeze Data
Diagnostic
Trouble Code
(DTC)
lf the ECM/PCM detects a problem, it will store it as a
code consisting of one letter and tour numbers
Depending on the problem, an SAE-defined code (Poxxx)
or a Honda-defined code (P'lxxx) will be output to the
tester.
lf no problem is detected,
there is no output.
YES
Engine SpeedThe ECN4/PCN4 computes engine speed from the signals
sent from the Crankshaft Position sensor.
This data is used for determining the time and amount of
fuel iniection.
Nearly the same as
tachometer indication
At idle speed:'97 - 98 models:
750 t 50 rpm'99 - 00 models:
730 f 50 rpm
YES
Vehicle SpeedThe ECM/PCM converts pulse signals from the Vehicle
Speed Sensor (VSSI into speed data.
Nearly the same as
speedometer indicationYES
Manifold
Absolute
Pressure (MAP)
The absolute pressure caused in the intake manifold by
engine load and speed.
With engin6 stopped:
Nearly the same as atmo-
spheric pressure
At idle speed:
2a - 41 kPa {210 - 310
mmHg, 8.3 - 12.2 inHg)
YES
Engine Coolant
Temperature
{ECT)
The ECT sensor converts coolant temperature into volt-
age and signals the ECM/PCM. The sensor is a thermistor
whose internal resistance changes with coolant tempera-
ture. The ECM/PCM uses the voltage signals from the
ECT sensor to determine the amount of injected fuel
With cold engine:
Same as ambient temPer-
ature and IAT
With engine warmed uP:
approx. 163 - 2'12'F
(73 - 100"c)
YES
Heated Oxygen
Sensor (HO25)
(Primary,
Sensor 1)
(Secondary
Sensor 2)
The Heated Oxygen Sensor detects the oxygen content in
the exhaust gas and sends voltage signals to the
ECMiPCM. Based on these signals, the ECM/PCM controls
the airlfuel ratio. When the oxygen content is high (that is.
when the ratio is leaner than the stoichiometric ratio), the
voltage signal is lower.
When the orygen content is low (that is, when the ratio
is richer than the stoichiometric ratio), the voltage signal
is higher.
0.0 - 1.25 V
At idle speed:
about 0.1 - 0.9
NO
(cont'd)
1 1-65
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Diagnostic Trouble Code (DTCI Chart
*: These DTCS will be indicated by the blinking of the Malfunction Indicator Lamp (MlL) with the SCS service connector
connected.**: The E (E)*u indicator tight and the Malfunction Indicator Lamp (MlL) may come on simultaneously.*1' AIT *3 '97 model +5; '99 - 00 models*2: MlT *4:'98 model
{cont'd)
11-75
DTC(MlL indication*lDetection ltemProbable CausePago
P0107 (3)Manifold Absolute
Pressu.e CircuitLow Input
Open or short in MAP sensor circuit
MAP sensor
ECMiPCM
't 'l-90
P0108 {3)
Manifold AbsolutePressure Circuit
High Input
Open in MAP sensor circuitMAP sensor
ECM/PCM
11-92
P01 1 1*3 (10)Intake Air
Temperature Circuit
Range/Performance Problem
. IAT sensor
11-95
P0112 (10)lntake Air
Temperature CircuitLow Input
Short in IAT sensor circuit
IAT sensorECM/PCM1 1-96
P0113 (10)lntake Air
Temperature Circuit
High lnput
Open in IAT sensor circuit
IAT sensor
ECM/PCM
'I 1-97
P0116 (86)Engine CoolantTemperature CircuitRange/Performance Problem
ECT sensor
Cooling system1 1-99
P0117 (6)Engine Coolant
Temperature Circuit
Low Input
Short in ECT sensor circuit
ECT sensor
ECM/PCM
1 1-100
P0118 (6)Engine Coolant
Temperature CircuitHigh Input
Open in ECT sensor circujt
ECT sensor
ECM/PCM
11-101
P0122 \11
Throttle Position
Circuit
Low Input
Open or short in TP sensor circuitTP sensor
ECM/PCM
11-103
P0123 l7l
Throftle Position
Circuit
High Input
Open in TP sensor circuit
TP sensor
ECM/PCM11-107
P0131 (1)
Primary Heated Oxygen Sensor
Circuit Low Voltage(Sensor 1)
Short in Primary HO2S {Sensor 1)
circuit
Primary HO2S (Sensor 1)
Fuel supply system
ECM/PCM
1 1-1 10
P0132 (1)Primary Heated Orygen SensorCircuit High Voltage(Sensor 1)
Open in Primary HO2S (Sensor 1) circuitPrimary HO25 (Sensor 1)ECM/PCM
'11113
P0133 (61)Primary Heated Oxygen Sensor
Slow Response(Sensor 1)
. Primary HO2S (Sensor 1). Exhaust system11'I 16
P0135 (41)
Primary Heated Oxygen SensorHeater
Circuit Malfunction
{Sensor 1)
. Open or short in Primary HO2S (Sensor'l) heater circuit. ECM/PCM11-12'l
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Troubleshooting
Diagnostic Trouble Code (DTCI Chart (cont'd)
*: These DTCS will be indicated by the blinking o{ the Malfunction Indicator Lamp (MlL) with the SCS service connector
connected.**: The E (El*s indicator light and the Malfunction Indicator Lamp {MlL) may come on simultaneously,*1; A/T *3: '97 model *5: '99 - 00 models*2: MlT *4: '98 model
11-76
DTClMlL indicationlDetection hemProbable Caus.Page
P0137(63)Secondary Heated Oxygen SensorCircuit Low Voltage{Sensor 2)
Shon in Secondary HO2S (Sensor 2) circuatSecondary HO2S (Sensor 2)ECM/PCM
'n-1t7
P0138 (63)Secondary Heated Oxygen SensorCircuit High VoltageOpen in Secondary HO2S (Sensor 2) circuitSecondary HO2S (Sensor 2)EC|\il/PCM11118
P0139{63)Secondary Heated Oxygen Sensor
lSensor 2i
Secondary HO2S (Sensor 2)11-120
P0141 (65)Second6ry Heated Oxygen Sensor HeaterCircuit Malfunction(Sensor 2)
Open orshon in Secondary HO2S (Sensor 2)heater circuitEC|V/PCtu11't2l
P0r71 (45)
System Too LeanFuel supply systemPrimary HOzS (Sensor 1)
Contaminated fuel
Exhaust leakage
11124
P0112 (45)
System Too RichFuel supplv systemPrimary HO2S (Sensor 1)
Contaminated fuel11 124
and
Po3ol ltr \P0302 112 |P0303 173 iP0304 \74 t
Random Mistirelgnition systemFuel supply system
IAC valveContaminated fuelLack of fuel
11-126
P0301 /71 \P0302 112 |P0303 173 |P0304 \7 4l
- Cylinder 1- Cylinder 2Cylinder 3- Cylinder 4Misfire Detected
Fuel injectorFuel injector circuitlgnition system't't 127
P0325*5{23)Knock Sensor {KS) Circuit MalfunctionOpen or shon in Knock Sensor (KS) circuitKnock Sensor (KS)ECM/PCt\411-130
P033s{4}Crankshaft PositionSensor CircuitCrankshaft Position SensorCrankshaft Positaon Sensor circuitE Cl\,l/PC l\,'!11-131
P0336(4)Crankshaft Position SensorRange/PerformanceCrankshaft Position SensorTiming belt skipped teeth11,131
P0420{67)Catalyst System Efficiency BelowThresholdThree Way Catalytic convenerSecondary HO2S {Sensor 2)'t1-200
P0441*3 (92)
Evaporative EmissionControlSystemInsulficient Purge Flow
EVAP Purge Control Solenoid valveEVAP Purge Control Solenoid valve circuitThrottle gody (purge port)TubingPCM
'It 205
P0451*5FuelTank Pressure Sensor CircuitBange/PerformanceFuel Tank Pressure SensorECM/PCMt't-208
(91iFuel Tank Pressure SensorCirclit Low InputOpsn orShort in FuelTank Pressure Sensor circuitFuel Tank Pressure SensorECM/PCt\411-209
P0453*r.5 {91)FuelTank Pressure Sensor CircuitHigh InputOpen in Fuel Tank Pressure Sensor circuitFuel Tank Pressure SensorECt /PCt\.111-211
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PGM-FI System
Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1)
The Heated Oxygen Sensors (HO2S) detect the oxygen content in the exhaust gas and signal the ECM/PCM. In operation,
the ECM/PCM receives the signals from the sensor and varies the duration during which fuel is iniected. To stabilize the
sensor's output, the sensor has an internal heater. The Primary HO2S (Sensor 1) is installed in exhaust pipe A.
HO2S:
ztRcoNtAEI.IMENT
s€NsoRTERMINALSVOLTAGE IVI
HEATEBTERMINALS
The scan tool indicates Diagnostic Trouble Code (DTC) P0131: A low voltage
Oxygen Sensor (HO2S) {Sensor 1} circuit,
RICH - AIR. . LEANFUELNATO
problem in the Primary Heated
37 - 98 models:
HEATER
The MIL has been reoorted on.DTC P0131 is stoied.
Problem verification:1. Do the ECM/PCM Reset Pro-ceoure.Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neutral) untilthe radiator fan comes on.Test-drive with the A/T in Eposition (M/T in 4th gear)Check the Primary HO2S{Sensor 1} output voltage withthe scan tool during accelera-tion using wide open throttle.
Intermittent f.ilure, system is OKat this time. Check fo. poor con-nections or loose wirer at C111(Primary HO2S, SeGor 1) and atrh€ ECM/FCM.
Check the fuel pressure (see page
11-178).
Repair the fuel supply system.
{To page 11'111}
1 1-1 10
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PGM-FI System
Primary Heated Oxygen Sensor (Primary HO2S) lSensor 1) (cont'd)
tFO133 lhe scan tool indicates Diagnostic Trouble Code (DTC) P0133: A slow response problem in the Primary Heated: Oxysen Sensor (Primarv 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 will be stored.
NOTE: lf DTC P0131, P0132 and/or P0135 are stored at the same time as DTC P0133. troubleshoot those DTCS first, then
troubleshoot DTC P0133.
Possible Cause
. Primary HO2S (Sensor 1) Deterioration
. Primary HO2S Heater (Sensor 1) Deterioration
. Exhaust system leakage
Troubleshooting Flowchart
- The MIL has b6€n reoorted on.- DTC P0133 is stored.
Problem Verilication:'1. Do the ECM/PCM Reset Procedure.2. Connect the scan tool.3. Start the engine. Hold theengine at 3,000 rpm with noload lin Park or neutrali untilthe radiator fan comes on.4. Connect the SCS service connector.5. Test-drive under the followingcondations,55 mph (89 km/h) steadyspeed- M in @ position (E position and Over Drive ON)*,(M/T in sth gear)- Until readiness code comes
Intermittent failure, system is OKat this time. Check tor poor con-nections or loose wires at C111(Primary HO2S, Sensor 1) and althe ECM/PCM.
Replace the Primary HO2S {Sen-sor 11.
1 1-1 16
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PGM-FI System
Fuel Supply System
[POliil The"""ntool indicates Diagnostic Troubte Code (DTC) p0'171:Thefuet system istoo lean.
[Fo17ZJ rh""""ntool indicates Diagnostic Troubte code {DTc) p0172:Thefuel svstem istoorich.
Description
By monitoring the Long Term Fuel rrim, long term malfunctions in the fuel system will be detected.lf a malfunction has been detected during two consecutive trips, the MIL will come on and DTc p0171 and/or pol72 will bestored.
NOTE: lf someof the DTCS listed below are stored atthesametimeas DTC P017'l and/or p0172, troubleshoot those DTcsfirst, then troubleshoot DTC P0171 and/or PO1i2.
P0107, P0108, P1128, P'1129: MAP Sensor
P0135: Primary HO2S (Sensor 1)Heater
P0137, P0138: Secondary HO2S {Sensor 2)P0141: Secondary H02S (Sensor 2) Heater
P0441*r: EVAP System lnsufficient Purge FtowP1456*,, P'l457 *?i EVAP System Insufficient purge Ftow
Possible Cause
DTC P0171
too lean
*1: '97 model*2: '98 - 00 models
Fuel Pump insufficient flow/pressure
Fuel Feed Line clogged. leaking
Fuel Pressure Regulator stuck openFuel Filter clogged
Fuel Injector clogged, air leakage
Gasoline doesn't meet Owner's Manual spec.Primary HO2S (Sensor 1) deteriorated
Valve Clearance
Exhaust leak
Fuel Pressure Regulator clogged, stuck closedFuel Return Pipe clogged
Fuel Injector leaking
Gasoline doesn't meet Owner's Manual spec.Primary H02S (Sensor 1) deteriorated
EVAP Purge Control Solenoid Valve leaking, stuck openedValve Clearance
DTC P0172
flch
11-124
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Emission Control System
Three Way Catalytic Converter {TWCI (cont'd}
1P0420 Thescantool indicates Diagnostic Trouble Code (DTC) P0420: Catalyst system efficiency belowthreshold.
DescriDtion
This system evaluates the catalyst's capacity by means of the HO2S (Primary and Secondary) output during stable driving
conditions. lf deterioration has been detected during three consecutive driving cycles, the MIL comes on and DTC P0420 will
be stored.
NOTE: lf some of the DTCS listed below are stored at the same time as DTC P0420, troubleshoot those DTCS first. then
troubleshoot DTC P0420.
P0137, P0138: Secondary HO2S (Sensor 2)
P0141: Secondary HO2S (Sensor 2) Heater
Possible Cause
. IWC Deterioration
. Exhaust system leakage
Troubleshooting Flowchart
- The MIL has been reDoried on.- DTC P0420 is stored.
Problem verification:1. Do the ECM/PCM Reset Procedure,2. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neutrali untilthe radiator fan comes on.3. Connect the SCS service connector.4. Test-drive 40 - 55 mph (64 - 88km/h) for approx. lwo minutes.Then decelerate for at least 3seconds with the throftle completely closed. Then reducethe vehicle speed to 35 mph
156 km/h), and try to hold ituntil the readiness code
Intermittent tailure. system is OKat this time.ls DTC P0420 indicated?
Check the TWC (see section 9).lI nocessary, replace the TwC.
11-200
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