Gear position HONDA CR-V 1999 RD1-RD3 / 1.G Workshop Manual
[x] Cancel search | Manufacturer: HONDA, Model Year: 1999, Model line: CR-V, Model: HONDA CR-V 1999 RD1-RD3 / 1.GPages: 1395, PDF Size: 35.62 MB
Page 35 of 1395
Standards and Service Limits
Automatic Transmission (cont'dl - Section 14
Differential (4WDl * Section 15
MEASUREMENTSTANOABD {NEW'
SteeringSection 17
* When using a new belt, adjust deflection or tension to new values. Run the engine for 5 minutes then turn it off.Readjust dellection or tension to used belt values.
MEASUREMENTSTANDARO INEWI
Wire Dia.o.D.Fiee LengthNo. of Coils
SpringsRegulator valve spring ARegulator valve spring BStator reaction springModulator valve springTorque convener check valve spring'97 model'98 - 00 modelsCooler relief valve springRelief valve spring2nd orilice control valve spring1-2 shitt valve spring2 3 shift valve spring3-4 shift valve spring1st accumulator spring4th accumulator spring B4th accumulator spring A2nd accumulator spring A3rd accumulator spring A2nd accumulator spring B3rd accumulator spring I3rd sub accumulator spring2nd accumulator spring CLock-up shift valve springLock-up timing valve springLock'up control valve spring3'4 orifice control valve springServo control valve springCPB valve spring4th exhaust valve spring
1.8 10.071)1.8 i0.071)4.5 (0.177)
1.4 {0.055)
1.1 (0.043)
1.2 (0.047)
1.0 (0.039)
1.1 (0.043)
0.7 (0.028)
0.9 (0.035)
0.9 (0.035)
0.9 (0.03s1
2.1 (0.083)
2.3 (0.091)
2.6 (0.102)
2.410.094)2.8 (0.110)
1.6 (0.063)
2.1 (0.083)
2.7 {0. r06)2.2lO.OA7)0.9 (0.035)
0.9 (0.035)
0.7 (0.028)
0.6 (0.024)
1.0 (0.039)
0.9 (0.035)
0.9 (0.035)
14.7 (0.579)
9.6 (0.378)
35.4 {1.394}9.4 (0.370)
8.4 (0.331)
8.4 (0.331)
8.4 (0.331)
8.6 (0.3391
6.6 (0.260i
7.6 {0.299}7.6 {0.299)7.6 {0.299)16.0 (0.630)
10.2 to.402l17.0 (0.669)
29.0 \1.1421'r7.510.689)
9.0 (0.354)
31.0 (1.220)17.0 (0.669)
14.510.571)7.610.299i8.1 {0.319}6.6 (0.260)
6.6 (0.260i
8.1 (0.319)
8.1 {0.319)6. t (0.240)
87.8 (3.457)
44.011.132130.31r.193)35.0 {1.378)
36.4 {1.433)32.4 tl.216J33.8 {r.331)37.1 (1.461)
34.8 (1.370)
41.3 (1.626)
57 .0 (2.2441
57 .0 12.244189.1 (3.508)
51.6 (2.031)
88.4 (3.480)
39.011.s35)94.313.713)20.7 10.8r5)38.2 (1.504)
39.0 (1.535)
68.0 (2.677)
73.7 12.902)8r.4 (3.205)
38.0 fl.496)37.9 (1.492)
52.1 (2.051)
41 .2 t .A5Al36.4 (1.4331
r 1.01.910.9
12.O12.78.213.422.0
26.426.8
13.814.22.915.9
2.66.3
32.047.A
20.8'18.3'19.5
Capacity f (US qt, lmp ql)1.2 (1.3, 1.1) at overhaul1.0 (1.1, 0.91 at fluid change
MEASUREMENTSTANDARD INEWI
Steering wheelRotational play at steering wheel circumferenceStaning load at steering wheelcircumferenceN {kgf, lbl) Engine running
0- 10 (0 - 0.39)
29 (3.0,6.6)
GearboxAngle of rack$uide-screw loosened lrom locked position'97, '98 models'99, '00 models10" 1 5"20" MAX.
PumpPump pressure with shut off valve closedkPa (kgvcm,, psi)6,900 - 7,800 (70 80,995 1,138)
Power steeringfluidRecommended tluidFluid capacity For overhaulI {US qt, lmp q0 For reservoir
Honda power steering fluid.0.85 (0.90,0.75)
0.4 {0.42,0.35)
Power steeringbelt*Deflection with 98 N {1O kgl,22lht)between pulleys11.0 14.5 (0.43 0.57)with used belt7.5 - 10.0 (0.30 0.40) with new belt
Belt tension N {kgt, lbf}Measured with belt tension gauge390 - 540 (40 - 55, 88 - 121) with used belt740-880 (75 90, 165 198)with new belt
2-10
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Page 53 of 1395
Starting System
Component Location Index
BATTERYTest, section 23
CLUTCH INTERLOCKswtTcH {M/T)Test, page 4-43Switch position adiustment,section 12
IA/T GEAR POSITION SWITCH {A/T}Test, section 14Reolacement. section 14
Test, page 4 5Solenoid Test, page 4-6Replacement, page 4-7Overhaul, page 4 8Reassembly, page 4-12Performance Test, Page 4-13
4-3
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Page 55 of 1395
Starting System
Starter Test
NOTE: The air temperature must be between 59 and'100'F (15 and 38"C) before testing.
Recommended Procedure:
. Use a staner system tester.
. Connect and operate the equipment in accordance
with the manufacturer's instructions.
. Test and troubleshoot as described.
Alte.nate Procedure:
. Use the following equipment:- Ammeter, 0 - 400 A- Voltmeter, 0 - 20 V (accurate within 0.1 volt)
Tachometer,0 - 1,200 rpm
. Hook up a voltmeter and ammeter as shown.
NOTE: After this test, or any subsequent repair. reset
the ECM/PCM to clear any codes (see section 1 1).
Check the Starter Engagement:
'1. Remove the No. 44 (15 A) fuse from the under-hood
fuse/relay box.
2. Turn the ignition switch to START (lll) with the shift
lever in E or E position (A/T) or with the clutch
pedal depressed {M/T). The starter should crank the
eng ine.
. lf the starter does not crank the engine, go to
step 3.
. lf it cranks the engine erratically or too slowly, go
to "Check for Wear and Damage" on the next
page.
NEGATIVE TERMINAL
4.
5.
6.
7.
8.
Check the battery, battery positive cable, ground.
staner cut relay, and the wire connections for loose-
ness and corrosion. Test again.
lf the staner still does not crank the engine, go to
step 4.
Unplug the connector (BLK /VHT wire and solenoid
terminal) from the starter.
Connect a jumper wire from the baftery positive (+)
terminal to the solenoid terminal.
The starter should crank the engine.
. lf the starter still does not crank the engine,
remove it, and diagnose its internal problem.
. lf the starter cranks the engine, go to step 6.
Check the ignition switch (see section 23).
Check the starter cut relay {see section 23}.
Check the IVT gear position switch (A/T) or the clutch
interlock switch (M[).
Check for an open in the wire between the ignition
switch and starter.
(cont'd)
4-5
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Page 56 of 1395
Starting System
Starter Test (cont'dl
Check lor Wear and D8mage
The starter should crank the engine smoothly and
steadily. lf the staner engages, but cranks the engine
erratically, remove it, and inspect the starter drive gear
and torque converter ring gear or flywheel ring gear for
oamage.
Check the drive gear overrunning clutch for binding or
slipping when the armature is rotated with the drive
gear held. lf damaged, replace the gears.
Check Cranking Voltage and Current Draw
Cranking voltage should be no less than 8.7 volts on Ay'T
models, and 8.0 volts on M/T moders.
Current draw should be no more than 230 amperes on
A,/T models, and 200 amperes on M/T models.
lf cranking voltage is too low, or current draw too high,
check for:
. dead or low battery.
a open circuit in starter armature commutator seg,
ments.
. starter armature dragging.
. shorted armature winding.
. excessive drag in engine.
Check Cranking rpm
Engine speed during cranking should be above 100 rpm.
lf speed is too low, check for:
a loose baftery or starter terminals.
. excesslvely worn staner brushes
. open circuit in commutator segments.
. dirty or damaged helical splines or drive gear.
a defective drive gear overrunning clutch.
Check Starter Disengagement
With the shift lever in @ or @ position (A,iT) or with the
clutch pedal depressed {M/T). turn the ignition switch to
START (lll). and release to ON (ll).
The starter drive gear should disengage from the torque
converter ring gear or flywheel ring gear when you
release the key.
lf the drive gear hangs up on the torque converter ring
gear or flywheel ring gear, check for
. solenoid plunger and switch malfunction.
. dirty drive gear assembly or damaged overrunning
clutch.
Starter Solenoid Test
1. Check the hold-in coil for continuity between the S
terminal and lhe armature housing (ground). The
coil is OK if there is continuity.
STARTER
B TERMINALMOUNTING NUT9 N.m 10.9 kgtm,7 tbtftl
TERMINAL
ARMATUREHOUSING(GROUND}
BLK/WHTWIRE
Check the pull in coil for continuity between the S
and M terminals. The coil is OK if there is continuity.
2.
4-6
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Page 89 of 1395
Disconnest the lilP connector from the control unit.
Csvity WireTest condition
R€conn€ct tho 14P connGctor to the control unit.
Test: Desired resultPossible cause it result is not obtained
BRNAr'VHTUnder all conditionsCheck for resistance to groundl
There should be 80 - 120 o.
Faulty actuator solenoid
Poor ground (G202)
An open in the wire1BRNUnder all conditionsCheck for resistance to groundl
There should be 40 - 60 0.
11BRN/BLKUnder all conditionsCheck for resistance to ground:
There should be 70 - 110 O.
2GRY
lgnition switch ON (ll),
main switch ON and
brake pedal depressed,
then released
Check for voltage to ground:
There should be 0 V with the pedal
depressed and battery voltage with
the pedal released.
. Faulty brake switch. An open in the wire
BLKUnder all conditionsCheck for continuity to ground:
There should be continuity.
. Poor ground (G401). An open in the wire
5GRNMHT
Brake pedal depressed,
then released
Check for voltage to ground:
There should be battery voltage with
the pedal depressed, and 0 V with
the pedal released.
Blown No.52 1'15 Alfuse in the
under-hood fuse/relay box
Faulty brake switch
An open in the wire
LT GRN/
RED
Set button pushedCheck for voltage to ground:
There should be battery voltage.Blown No. 52 {'15 A} fuse in the
under-hood fuse/relay box
Faulty horn relay
Faulty sevresume switch
Faulty cable reel
An open in the wire7LT GRN/
BLK
Resume button pushed
10RED/BLU
lgnition switch ON lll)Attach to ground:
Cruise indicator light in the gauge
assembly should come on.
Elown bulbBlown No. 25 (7.5 A) tuse in theunder-dash fuse/relay box
Faulty dimming circuit in the gauge
assembly
An open in the wire
ELU^r'r'HT
lgnitjon switch ON {ll}and main switch ON;
raise the front of the
vehicle, block one wheel
and rotate the other
wheel slowly.
Check for voltage between the
ELUA/VHT @ and BLK O terminalsl
There should be 0 - 5 V or more-0 - 5 V or more repeatedly.
Faulty vehicle speed sensor (VSS)
An open in the wire
r3LT GRN
lgnition switch ON {ll}and main switch ONCheck for voltage to ground:
There should be battery voltage.
Blown No. 14 (7.5 A) fuse in theunder-dash fuse/relay box
Faulty main switch
An open in the wire
l4PNK
A'/T: Shift lever in E, EotE
lvl/T: Clutch pedal
releaseo
Check for continuity to ground:
There should be continuity.NOTE: There should be no continu-
ity when the shift lever is in otherpositions or when the clutch pedal is
oepresseo.
Faulty A/f gear position switch 1A,/TlFaulty or misadjusted clutch switch
fi{/r)Poor ground (G101)
An open in the wire
BLU
Start tho engine. turnthe main switch ON, anddrive the vehicle over 25
mph (40 km/h)with the
crurse control set
Check for voltage to ground:
There should be approx.5 V
. Faulty cruise control unit. Shod to ground
*: '98 - 00 models with Automatic Transmission.
4-39
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Page 266 of 1395
Troubleshooting
Troubleshooting Procedures (cont'dl
Symptom Chart
Listed below are symptoms and probable causes for problems that DO NOT cause the Malfunction Indicator Lamp (MlL) tocome on. lf the MIL was reported on, go to page 11-60.Troubleshoot each probable cause in the order listed (from left to right) until the symptom is eliminated,The probable cause and troubleshooting page reference can be found below.
Other Probable Causes for an engine that will not start:- Compression- Intake air leakage- Engine locked up- Timing belt- Starting system- Overheating- Battery
SYMPTOMPROBABLE CAUSE
Engine will not sta rt4, 2,3,5,20, 't5, 1
Hard starting2, 4, 12,17, 14, 't9
Cold fast idle too low7, a,9, 6, 17
Cold fast idle too high7,8,9,11,10
ldle speed fluctuates9,7,8, 't1, 10
Misfire or rough runningTroubleshoot for misfire on pages '11-126, 1|21LOl/\/ power2, 10,11, 13, '17, 18,20
Engine stalls2, 4, 12,1,20,9,5, 't6
Probable Cause List (For the DTC Ch8rt, see page ll-75.)
Probable CausePageSystem
Engine controt ruoaute (ecvtffi'I11-42
I 1-178Fuel oressure
PGM-Fl main relav
lgnition system
Crankshatt Position/Top Dead Center/Cylinder position sensor circuit
Intake Air Temperature (lAT) sensor ctrculr
ldle Air Control (lAC) Vatve
Fast idle thermo valve
ldle speed adjustment
Throttle body
Throftle cable
Manifold Absolute P."""rr"ffi
Throftle Position (TP) sensor
Barometric pressur" (gnno-
Ay'T gear position signal
Brake switch signal
Air Cleaner
Three Way Catalytic Converter (TWC)
Evaporative emission (EVAP) control
Contaminated fuel
1 1- 187
Section 4
5't1-'t31,146
6I ' t-95
711-152
81'l-168
1 1- 169
1011-196'1111-'194
12'1 'l -90
1 1- 103
1411-137
15Section 14
161 1- 166
17r 1-194
181 1,199'1911-203
20
11-64
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Page 270 of 1395
Troubleshooting
PCM CONNECTOR B I25PI
Powertrain Control Module Terminal Arrangement -'97 Model (cont'dl
Wire side of female terminalsPCM CONNECTOR B I25P}NOTE: Standard battery voltage is l2 V.
1 1-68L
TerminelnumbercolorTerminalnameOescriptionSignal
1LS 1A/T CLUTCHPRESSURE CONTROLSOLENOID VALVE -)
Drives A,/T clutch pressure controlsolenoid valveWith ignition switch ON (ll): duty con-trolled
2REDLS + (A"/T CLUTCHPRESSURE CONTROLSOLENOID VALVE +)
Drives A,/T clutch pressure controlsolenoid valveWith ignition switch ON (ll)r duty controlled
38LU//EL
SHA (SHIFT CONTROLSOLENOID VALVE A)Drives shift control solenoid valve A.In 2nd, R position. in 2nd and 3rd gear inD4, D3 position: Battery voltageIn lst gear in D4, D3 position, in 4th gear
in D4 position: 0 V
4GRN/BLKLC B (LOCK-UP CONTFOLSOLENOID VALVE B)Drives lock-up control solenoidvalve B,With full lock-up; Baftery voltageWith half lock-up: duty controlled
5YELLC A (LOCK.UP CONTROLSOLENOID VALVE A)Drives lock-up control solenoidWith lock'up ON: battery voltageWith lock-up OFF:0 V
IPNKATPD3 (Ay'T GEARPOSITION SWITCH}Detects A/T gear position switchsignal. _
In D3 position:0 Vln any other position: battery voltage
11GRN/VVHT
SHB (SHIFT CONTROLSOLENOID VALVE 8}Drives shift control solenoid valve B.In 1st, 2nd position, in 1st and 2nd gear inD4, D3 position: Battery voltageIn R position, ;n 3rd gear in 04, D3, in 4thgear in D4 position: 0 V
12WHT/BEDILU (INTERLOCK
CONTROL UNITiDetects interlock control unh signal.With ignition switch ON (ll)and brakepedal depressed: battery voltage
GRN/BLKD4IND (04 INDICATORLIGHT}Drives Dl indicator light.With D4 indicator light turned ON: batteryvoltageWith D4 indicator light turned OFF: 0 V
14NMSG (MAINSHAFT
SPEED SENSOR GROUND}Ground tor mainshaft speed sensor.
REDNM (MAINSHAFT SPEEDSENSOR)Detects mainshaft speed sensorsrgnal,With engine running: pulses
16ATPR (A"/T GEARPOSITION SWITCH)Detects A/T gear position switchsrgnal.InRposition:0VIn any other position: battery voltage
1'lBLUATP2 (A./T GEARPOSITION SWITCH)Detects A/T gear position switchsrg nal,In 2nd position: 0 VIn any other position: battery voltage
18BRNATP1 (4,,/T GEARPOSTTTON SWTTCH)Detects A/T gear position switchsrg nal,ln lst position: 0 VIn any other position: battery voltage
22GBNNCSG (COUNTERSHAFT
SPEED SENSOR GROUND)Ground tor countershaft speedsensor,
23BLUNC (COUNTERSHAFT
SPEED SENSOR)Detects countershaft speed sensorsrgnal.With agnition switch ON (ll), and lrontwheels rotating: pulses
24YELATPD4 (M GEARPOSITION SWITCH)Detects A,/T gear position switchsrgnal.In D4 positionr 0 VIn any other position: battery voltage
25LT GRNATPNP {A/T GEARPOSITION SWITCH)Detects A/T gear position switchsignal.In park or neutral:0 VIn any other position: about 5 V
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Page 276 of 1395
Troubleshooting
Powertrain Control Module Terminal Arrangement -'98 - 00 Models (cont'dl
PCM CONNECTOR D (16P)NOTE: Standard battery voltage is 12 V.
i1:A/T *3:'98 model'2: M/T *4:'99 00 models
ECM/PCM CONNECTOR D {16P}
Wire side of lemaleterminals
D€s4riptionSign!l
YELLC A {LOCK,UP CONTBOLSOLENOID VALVE A)Oriv€s lock'up conrrol solenoid valve A.With lock-up ON: b6ttery voltagsWith lock-up OFF:0 V
2+1GBN,M/HT
SHB (SHIFT CONTROLSOLENOIO VALVE B)Drives shift controlsolenoid valve B.In 1st, 2nd position, in lst and 2nd gear an D4, D3(D)11 position: battery vohag€In P, R, N position, in 3rd geaf in D1, D3 (D)*.position, in 4th gear in D4 (D)*r positionr0 V
GRN/BLKLC 8 (LOCK,UP CONTROLSOLENOID VALVE B}Drives lock up controlsolenoid valve B.With full lock-up: 8attery voitageWith half lock'uprduty controlled
BLK/YELVBSOL (BATTERY VOLTAGEFOR SOLENOID VALVE}Pow€r source of solenoid valvs.With ignition switch ON (ll): batteryvoltageWith ignition switch OFF| 0 V
ATPR {AI GEAE POSITIONSWITCH)Delscls A/T gear posrtion swirch srgnal.In any other positjon: battsry voltage
BLU,ryEL
SHA (SHIFT CONTROLSOLENOID VALVE A)Drives shift conrrol solenoid valvp A.In 2nd, R position, an 2nd and 3rd ge6r in D4, D3(D)r' posilion: batlery voltageIn 1st gear in 04, 03 {D)}. position, in 4th gear inD4 (D)*. position, in P, N position:0 V
PNKATPD3 (AT GEAR POSITIONswrTcH)Detects A,/T g€ar poshion swirch sign6l.In D3 position:0 Vh any other posiiion: ban€ryvoltage
PNK
ODSW (OVER.DBIVE SWITCH)Detects OVEF-DRIVE swirch sagnal.With Ovor Drivs OFF (O/D OFF indicator lightturned ON): 0 VWilh Ovsr Drivs ON (O/D OFF indicrto.lashtturned OFF): about 5 V
9''YELATPDI}3, O}I {AT GEARPOStTtON SWTTCH)Dot€cts A/T g€ar position swirch signal.In D4r3, O*. position:0 VIn any other posilion: battery voltage
10.,BLUNC (COUNIERSHAFT SPEEDSENSOR)Detscts counl€rshaft speed sensorWith ignition switch ON (ll), and ffonr wheels
REDNM IIVAINSHAFT SPEEDSENSOB)Detects mainshaft speed sensor sign6ls.Wilh engine running: pulses
NMSG {MAINSHAFTSPEEDSENSOB GBOUND)Ground for mainshaft speed sensor-
'13*1LT GRNATPNP (AT GEAR POSITIONswtTcH)Delects A,/T gear position switch signat.In park or n€utral:0 Vh any other posilion: about 5 V
8LUATP2 (AT GEAR POSFIONswrTcH)Dstects A,/T gear position switch signal.h any othsr position: battery voltsgs
15.'BRNATP1 {AT GEAR POSITIONswrTcH)Detscts A/T gear position switch signal.In any other position: htteryvoltage
t6''GRNNCSG {COUNTERSHAFTSPEED SENSOR GROUND}Grouod for counterchaft sp€ed s€nsor.
11-74
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Page 282 of 1395
PGM-FI System
System Description
INPUTS
CKP/TDC/CYP Sensor
CKF Sensor
MAP Sensor
ECT Sensor
IAT Sensor
TP Sensor
Primary HO2S
Secondary H02S
vss
KS*5
BARO Sensor
ELD*6
Starter Signal
ALT FR Signal
Air Conditioning Signal
Ay'T Gear Position Signal*1
Baftery Voltage (lGN.1)
Brake Switch Signal
PSP Switch Signal
Fuel Tank Pressuae Sensor*4. *5
Countershaft Speed Sensor*1
Mainshaft Speed Sensor*r
OVER-DRIVE Switch Signal*s
ENGINE CONTROL MODULE (ECM)/
POWERTRAIN CONTROL MODULE (PCM) OUTPUTS
|iuel 1"j""- Th,rhg ""d Drrafr";-l
Et*-.nt"tdt"cont.orl
to,r*,c;;trffi;]
l.----.---:. .Lrgnrnon |lmrng Lonrror I
Ecir/PcM B*k',p Fr""il]
m;"t-ll-r*'io*l
Fuel Injectors
PGM-Fl Main Relay (Fuel Pump)
MIL
IAC Valve
Ay'C Compressor Clutch Relay
Radiator Fan Relay
Condenser Fan Relay
ALT
tcM
EVAP Purge Control Solenoid
Valve
Primary HO2S Heater
Secondary H02S HeaterEVAP Bypass Solenoid Valve*a *5
EVAP Control Canister Vent Shut
DLC
Lock-up Control Solenoid Valve*l
Shift Control Solenoid Valve*1
Ay'T Clutch Pressure Control
Solenoid Valve*1
D4 Indicator Light'1 *3, *a
D Indicator Light,l *5
OVER-DRIVE OFF Indicator
Lighl*t *:
*1: A/T {3:'97 model'2: M/f +4:'98 model*5: '99 - 00 models"6: USA
PGM-Fl System
The PGM-Fl system on this model is a sequential multiport fuel injection system.
Fuel iniecior Timing and Duration
The ECM/PCM contains memories for the basic discharge durations at various engine speeds and manifold pressure. The
basic discharge duration, after being read out from the memory, is further modified by signals sent from various sensors
to obtain the final discharge duration.
ldle Air Control
ldle Air Control Valve (lAC Valve)
When the engine is cold, the Ay'C compressor is on, the transmission is in gear, the brake pedal is depressed, the P/S load
is high, or the alternator is charging, the ECM/PCM controls current to the IAC Valve to maintain the correct idle speed.
lgnition Timing Control
o The ECM/PCM contains memories for basic ionition timing at various engine speeds and manifold air flow rates.
lgnition timing is also adjusted for engine coolant temperature.
. A knock control system was adopted which sets the ideal ig nition timing for the octane rating of the gasoline used.*s
Other Control Funstions
1. Starting Control
When the engine is started. the ECM/PCM provides a rich mixture by increasing fuel injector duration.
2. Fuel Pump Control
. When the ignition switch is initially turned on (ll). the ECMiPCM suppli€s ground to the PGM-FI main relay that
supplies current to the fuel pump for two seconds to pressurize the fuel system.
. When the engine is running, the ECM/PCM supplies ground to the PGM-FI main relay that supplies current to the
fuel oumo.
. When the engine is not running and the ignition is on, the ECM/PCM cuts ground to the PGM-FI main relay which
cuts current to the fuel pump.
1 1-80
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Page 312 of 1395
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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