1999 HONDA CR-V diagnosis

Fuel Cut-off Control
. During deceleration with the throttle valve closed, current to the fuel injectors iscutoffto improvefuel economyat
speeds over 970 rpm ('97 - 98 models), 920 rpm ('99 - 00 modelsl.
. Fuel cut-off action also takes place when engine speed exceeds 6,500 rpm ('97 - 98 models), 6900 rpm ('99 - 00
models), regardless of the position of the throttle valve, to protect the engine from over-rewing.
With Ay'T model. the PCM cuts the fuel at engine speeds over 5,000 rpm when the vehicle is not moving.*'
4,./C Comoressor Clutch Relav
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 a smooth transition to the Ay'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,
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.
PCM Fail-saf e/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-pre
grammed value for that sensor that allows the engine to continue to run.
2. Back-up 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 IMalfunction Indicator Lamp (MlL)l
When an abnormality occurs in a signal from a sensor, the ECM/PCM supplies ground for the MIL and stores the DTC
in erasable memory. When the ignition is initially turned on {ll), the ECM/PCM supplies ground for the MIL for two
seconds to check the MIL bulb condition.
4. Two Trio Detection Method
To prevent false indications, the Two Trip Detection Method is used for the HO2S*1, fuel metering-related. idle control
system, ECT sensor 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 (ll) 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 {'97 model)
A "Driving Cycle" consists of starting the engine, beginning closed loop operation, and stopping the engine. lf misfir-
ing that increases emissions or EVAP control system malfunction is detected during two consecutive driving cycles.
or TWC deterioration is detected during 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.
*1: '97 - 98 models*2: '99 - 00 models
5.
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Electronic Control System
The electronic control svstem consists of a Powertrain Control Module (PCM), sensors, a linear solenoid, and four solenoid
valves. Shifting and lock-up are electronically controlled for comfortable driving under all conditions. The PCM is located
below the dashboard, under the kick panel on the passenger's side.
'97 - 98 Mod€ls
PGM.FIControl Sy3t6m
Throttl€ Poshion SensorSignalVehicle Sp.ed SensorSignal
Engino Coolant TamperetureService Check connectorSonsor Signrl
A/T Control Sy3tem
INTERLOCK
Shift Cont.ol
Shift ControlSolenoid valve ACONTROL UNITr
RShift ControlSolenoid Valve B
N
Linear SolenoidDr
Lock-up Control
Ds
Lock-up ControlSolenoid Valve A2
Lock-up ConirolSol6noid valvo B1
M.inshaft Spoed SensorSignel-D! Indicator Light
Count€rahaft Speedsensor SignelSelt-Oiagnosb signel
I
Sell-DiagnosisFunction
l-
{cont'd)
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Description
PCM
PGM.FIControl System
Throttle Position SensorSignelVehicle Speed SensorSignal
Engin€ Coolsnt TomperatureSen30r SignalService Ch€ck Connectol
A/T Control Svstem
INTERLOCK
Shift Control
Shift ConlrolSolenoid Valve ACONTROL UNITr
RShift ControlSolenoid Valve B
N
Linear SolenoidD
Lock-up Control
2
Lock-up ControlSolenoid valve A1
Lock-up ControlSolenoid Valve BOver-DriveSwitch Signal
Mainshaft Speed SensorSignalE Indicator Light
Countershaft SpeedSensor SigntlSelt-Oiagnosis SigndSelf-DiagnosisFunc{ion
O/D OFFIndicetor Light
Electronic Gontrol System (cont'd)
'99 - 00 Models
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Electrical Troubleshooting ('97 Model)
Troubleshooting Flowchart - Lock-up Control Solenoid Valve A
Possible Cause
. Disconnected lock-up controlsolenoid valve A/B assembly
. Short or open in lock-up controlsolenoid valve A wire. Faulty lock-up control solenoid
lf the Honda PGMTester is available:
NO
Wire side of female terminals
PCM CONNECTORS
. OBD ll Scan Tool indicates CodeP1753.. Self-diagnosis i@ indicatorlight blinks once.
Check and record the freeze datarn case it is needed later for prob-lem verification.
Perform the lock,up controlsolenoid valve A test using theHonda PGM Tester.
The solenoid is OK at this time.Verify that all connectors in thecircuil are making good contact,
Did the solenoid pass the test?
Check for a Short to Power:r. I urn rne tgntUon swttch ut-f.2. Disconnecr the A (32P) and B(2 5P) connectors from thePCM.3. Turn the ignition switch ON (ll).4. Measure the voltage betweenthe 85 and A9 or A22 terminals.
Repair short to power in the wirebetween the 85 terminal and thelock-up control solenoid valve A.
ls there voltage?
Measure Lock-up Control Sole-noid Valve A Resistance:1. Turn the ignition switch OFF.2. Measure the resistancebetween the 85 and A9 or A22
Check for loose terminal fit in thePCM connectors, ll necessary,substitule a known-good solenoidvalve assembly or PCM andrecheck,
ls the resistance 12 25 ()?
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Electrical Troubleshooting ('97 Model)
Troubleshooting Flowchart - Lock-up Control Solenoid Valve B
Possible Causo
. Disconnocted lock-up controlsol€noid valve A/B assembly
. Short or op€n in lock-up control3olenoid vrlve B wi.e. Faulty lock-up control solenoidvalve B
Wire side of female terminals
PCM CONNECTORS
. OBO ll Scan Tool indicates CodeP1758.. Self-diagnosis pr- indicator lightblink3 twice.
Check and record the {reeze datajn case it is needed later for prob,lem verification.
The system is OK at this time.Verify thet dll connectors in thecircuit are making good contact.
Did the code return?
Check tor a Short to Powerl1. Turn the ignition switch OFF.2. Disconnect the A (32P) and B(25P) connectors from thePCM.3. Turn the ignition switch ON {ll).4. Measure the voltage betweenthe 84 and Ag ot A22 tetminals,
Repair short to power in tho wirebstween the 84 terminal and thelock-up control rolenoid valve B.
Measure Lock-up Control Sole-noid Valve B Resistance:1. Turn the ignition switch OFF.2. Measure the resistancebetween the 84 and Ag orA22 terminals.
Check tor loose terminal tit in thePCM connectors, It necessary,subslitute a known-good sole-noid valve assembly o. PCM andrech€ck.
ls the resistance 12 25 O?
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14-66
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Electrical Troubleshooting {'97 Model}
Troubfeshooting Flowchart- AIT Gear Position Switch (Short)
Po$ible Cause
' Short in A/T gear position switch
. Faulty A/T gear position switch
NOTE: Code P1705 (5) is caused whenthe PCM receives two gear positionanputs at the same time.
. OBO ll Scan Tool indicat€s CodeP1705.' Selt-diagnosis p1- indicator tightblinb Iive times.
Check and record the freeze datain case it is needed later for prob-lem verification.
Observe the A/T G€ar Po3itionIndicator:1. Turn the ignition switch ON lll).2. Observe the A./T gear positionindicator, and shilt to eachposition separately.
Does any indicator stay onwhen the shift lever is not inthat position?
The system is OK .t this time.Ch6ck ihe wii6 harness for dam-490,
Do allgear position indicatorsgo out?
Measure ATP R Voltago:1. Shitt to all positions other thantr.2. lMeasure the voltage betweenthe 816 and Ag or A22 termi-nals.Check tor 3hort in the wirebetwaen the 816torminal and thoA/T gear pGilion switch or A/Tgsar posiiion indicator. ff wire isOK, check for 10036 torminal flt inlhe PICM connectoB. It necessary,substitute a known-9ood PCMand recheck.
Measure ATP NP Voltage:1. Shift to all positions other thanNorE.2. Measure the vohage betweenlhe 825 and Ag or A22 termi-nals.Chock for ahort in the wirebetw€en tho 825 torminal end theA/T 96.r pGition indicstor, or asho.t in tha wiro! b€tween theA/T gear po3ition indicator andthe A/T g€ar position lwitch. lfwircs ar€ OK, ch6ck for loos€ ter-minal fit in the PCM connectors. Itnece3sary, substitute a known-good PCM and recheck.
ls there battery vohage?
PCM CONNECTORS
Wire side of female terminals
ATP NP {LT GRNI
14-68
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Electrical Troubleshooting ('97 Model)
Troubleshooting Flowchart - Countershaft Speed Sensor
Possible Cause
. Loose or faulty connection betweenih€ PCM and vehicle harness. Disconnected countershaft spoedsensor conneclor. Short or open in countershaft speed
. Faulty counteBhaft speed lensor
lf the Honda PGMTester is available:I
J
COUNTERSHAFT SPEED SENSOR
CONNECTOR
ll-'T,ll-rT
ral
YIL__l
Terminal side of male terminals
. OBO ll Scan Tool indicates Codem720.' solt-diagnosis iD!' indicator lightblink3 nine tim6s.
Check and record the freeze datain case it is needed later for problem verification.
Connect the Honda PGM Tester,and test-drive the vehicle withthe tester in Data Link or snap'Shot mode, Make sure the coun-tershaft speed sensor reads thesame as the vehicle speed sensorlVSS).
The countershaft sooed sensor isOK sr this time. Veritv that allconnecloas in the circuit aremaking good contacl.
Check the countershaft speedsensor installation, and check itfor damage.
ls the countershaft speed sen-sor installed properly, and notdamaged?neinstall or roDlaco and recheck.
Measuro CountoBhaft Speed Sen-sor Relbtance at the Sensor Con-nector:1. Disconnect the 2P connectorfrom the countershaft speedsensor connector.2. Measure the resistance of thecountershaft speed sensor.
ls the resistance 400 - 600 o?
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Electrical Troubleshooting {'97 Model)
Troubleshooting Flowchart - Mainshaft Speed Sensor
Po$ible Cau3o
. Disconnocted mainshaft speod sen-sot connectot. Short or open in mainsh.ft sp6ed
' Faulty meinshaft spoed sensor
NOTE: Code P0715115) on the PCMdoesn't always mean there's an electricalproblem in the mainshaft or counlersharlspeed sensor circuit; code P0715(15) mayalso indicate a mechanical problem in thetransmission. Check the freeze data witha Honda PGM Tester. lf the mainshaftspeed sensor rpm was 0, proceed withthis troubleshooting. lf not, the probablecause is a mechanical problom within thetransmission,
MAINSHAFT SPEEOSENSOR CONNECTOR
_E_
ItiT,ll-F=r
9t
LJ
Terminal side of male terminals
PCM CONNECTOR B {25P'
Wire side of female terminals
. OBD ll Scan Tool indic.t6 Codem715.. Self-diagnosis E indic.tor lightindicatag Code 15.
Check and record the freeze datain case it is needed later {or prob,lem verification.
Check the mainshaft and counter-shaft speed sensor installation,and checkthe sensors for damage.
Are the mainshaft and counter-shaft speed sensors installedproperly, and not damaged?Reingtall or reolace and recheck.
Meaaure MaiNhatt Spoed Sen3orR6sist!nce at the Sensor Con-necaor:1. Disconnect the 2P connectorfrom the mainshaft speed sen-sor connector.2. lreasure the resistance of themainshaft speed sensor.
ls the resistance 400 - 600 O?
Check Mainahaft Speed Sensortor a Short Circuit:1. Disconnect the B (25P) connec-tor lrom the PCM.2. Check for continuity betlveenbody ground and 815 terminaland the 814 terminal individu-
ReDair short in the wir€6 b€t reenthe 815 and 814 torminals andthe mainsh!ft sp€ed sensor.
To page l4-79
14-78
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