1999 HONDA CR-V Start switch

Description
Rear Differential
Outline
The Real-time 4WD-Dual Pump System model has a hydraulic clutch and a differential mechanism in the rear differential
assembly. Under normal conditions, the vehicle is driven by the front wheels. However, depending on to the driving force
of the front wheels and the road conditions. the system instantly transmits appropriate driving force to the rear wheels
without requiring the driver to switch between 2WD (tront wheel drive) and 4WD (four wheel drive). The switching mecha-
nism between 2WD and 4WD is integrated into the rear differential assembly to make the system light and compact.
ln addition, the dual-pump system switches off the rear-wheel-drive force when braking in a forward gear. This allows the
braking system to work properly on models equipped with an Anti-lock Braking System (ABS).
Construction
The rear differential assembly consists of the torque control differential case assembly and the rear differential carrier
assembly. The torque control differential case assembly consists of the differential clutch assembly, the companion
flange, and the oil pump body assembly. The rear differential carrier assembly consists of the differential mechanism. The
differential drive and driven gears are hypoid gears.
The oil pump body assembly consists of the front oil pump, the rear oil pump, the hydraulic control mechanism, and the
clutch piston. The clutch piston has a disc spring that constantly provides the differential clutch assembly with a preset
torque to Drevent abnormal sound.
The clutch guide in the differential clutch assembly is connected to the propeller shaft via the companion flange, and it
receives the driving force lrom the transfer assembly. The clutch guide rotates the clutch plate and the front oil pump in
the oil pump body.
The clutch hub in the differential clutch assembly has a clutch disc that is splined with the hypoid drive pinion gear. The
hypoid drive gear drives the rear oil pump.
The front and rear oil pumps are trochoidal pumps. The rear oil pump capacity is 2.5 percent larger that the front oil pump
to handle the rotation difference between the front and rear wheels caused by worn front tires and tight corner braking.
The oil pumps are designed so the fluid intake works as a fluid discharge when the oil pumps rotate in reverse. Genuine
Honda CVT fluid is used instead of differential fluid.
Operation
When there is a difference in rotation speed between the front wheels (clutch guide) and rear wheels (hypoid driven gear),
hydraulic pressure from the front and rear oil pumps engages the differential clutch, and drive force from the transler
assembly is applied to the rear wheels.
The hydraulic pressure control mechanism in the oil pump body selects 4WD mode when the vehicle is started abruptly,
or when accelerating in a forward or reverse gear (causing rotation difference between the front and rear wheels). or
when braking in reverse gear {when decelerating). lt switches to 2WD mode when the vehicle is driven at a constant speed
in forwar! or reverse gear (when there is no rotation difference between the front and rear wheels), or when braking in a
fo rwa rd gear (when decelerating).
To protect the system, the differential clutch assembly is lubricated by hydraulic pressure generated by the oil pumps in
both 4WD and 2WD modes. Also, the thermal switch relieves the hydraulic pressure on the clutch piston and cancels 4WD
mode if the temDerature of the differential fluid rises above normal.
www.emanualpro.com

Troubleshooting Precautions
ABS lndicalor
1 lf the system is oK, the ABS indicator goes off two seconds after turning the ignition switch oN 1l) wathout staningthe engine, and then comes on again and goes off after two seconds. This occurs because the ABS control unit isturned on by the lG2 power source.2. The ABS indicator comes on when the ABS control unit detects a problem in the system. However, even thouoh thesystem is operating properly, the ABs indicator will come on too, under the following conditions:. Signal disturbance
. Wheel spin
. Only drive wheels rotate. Battery voltage fluctuates
To determine the actual cause of the problem, question the customer about the problem, taking these conditions intoconsideration:
3 When a problem is detected and the ABS indicator comes on, the indicator can stay on until the ignition switch isturned OFF, or it can automatically go off, depending on the mode.. Indicator stays on untilthe ignition switch is turned off: When the system is in the system down mode.. Indicator automatically goes off: When the system is in the control inhibition mode.4 The ABS indicator stays on when the system is reactivated without erasing the DTC, but it goes off after starting thevehicle.
When the wheel sensor system is faulty and the ABS indicator comes on. the algorithm of the system automatically turnsoff the ABS indicator after the wheel speed signal returns to the normal speed. Also, when the DTc is erased, the cpu isreset and the ABS indicator goes off when the system checked out normal by the initial diagnosis.Therefore, test-drive the vehicle after servicing the wheel sensor system. and be sure that the ABS indicator does notcome on.
5 When the ABS control unit outputs battery voltage to the gauge assembly, the ABS indicator ooes off.
Diagnostic Trouble Code (DTCI
1. The diagnostic trouble code (DTc) is memorized when a problem is detected and the ABS indicator does not go off,or when the ABS indicator comes on.The DTc is not memorized when the ABS indicator comes on unress the cpu is activated,2 The memory can hold any number of DTCs. However, when the same DTc is detected twice or more, the tater one iswritten over the old one.
Therefore, when the same problem is detected repeatedly, it is recorded as one DTC.3. The DTCs are indicated in the order of ascending number, not in the order they occur.4. The DTCS are memorized in the EEPROM (non-volatile memorv).Therefore, the memorized DTcs cannot be canceled by disconnecting the battery. perform the specified procedures toerase the DTCS.
Self-diagnosis
1. Self-diagnosis can be classified into these four categories:' Initial diagnosis: Performed right after the eng ine starts and untir theABS indicator goes off.. Except ABS control: Performed when the ABS is not functioning.. During ABS control: Performed when the ABS is functioning.. During warning: Performed when the ABS indicator is ON.2. The system performs the fo|owing contrors when a probrem is detected by the serf-diagnosis:. ABS indicator ON. Memorv of DTC. Mode changetothe "system down mode,, or the ,,control inhibition mode,,.
MODEABS INDICATORMAIN
RELAY
SOLENOID
VALVECPURestart conditionDTC
SYSTEM
DOWNONNo
operation
Drive
inhibitionOperation*rlgnition
switchoFF - ON l)Memory
CONTROL
INHIBITIONONNo
operal|on
Drive
inhibitionOperationAutomaticlMemory
*1: Except CPU failure
19-36
www.emanualpro.com

Diagnostic Trouble Code (DTC)
Diagnostic Trouble Gode IDTCI Indication
NOTE: This operation can also be done with the Honda pGM Tester.
1. Connect the SCS service connector to the service check connector (2P) located on the passenger's side of the centerconsote.
2. Turn the ignition switch ON (ll).
NOTE; Do not press the brake pedal whenturningthe ignition switch.
3 Record the blinking frequency of the ABS indicator. The brinking frequency indicates the DTc.
4. Turn the ignition switch OFF. and remove the SCS service connector.NOTE: The Malfunction Indicator Lamp (MlL) will stay on after the engine is startsd if the SCS seryica connecror rsconnected.
5. Erase the DTC.
Conditions for DTC indication. The vehicle is stopped.. The SCS service connector is connected before the ignition switch is turned ON flt).. The brake pedal is released.. The SCS service connector remains connected during this procedure.
The DTC indication stops and the ABS control unit axecutos tha softwaro lunction if at least one of tho following condi-tions i3 satisfiod:
. The vehicle is not stoooed.. The ABS control unit receives the normal signal (which is for the ABS control unit) from a Honda pGM Tesrer.. The SCS service connector is disconnectod during this procedure.
NQTE: The illustration of gauge assembly shows the '97 - 98 models. The '99 - oo models are similar.
SEFVICE CHECKCONNESTOR I2P}
GAUGE ASSEMBLY
A8S II{DEATOR
u.s.A.
@
CANADA
@
19-38
www.emanualpro.com

- With ths ignition switch ONllll, the ABS indicatol doesnot go ott.- Atte. driving, the ABS indica-lot comas on.- With the SCS service connec-tor connocted (s€€ page 19.381,DTGr 11 - 18 sre indbated.
Check the whcol sensor circuit:1. Disconnect the ABS controlunit 26P connector.2, Nleasure the resistancebetween the appropriate wheelsensor l0) and 1'l) circuit termi-nals {see table).
. Ropair op€n in th. {01 o. lll cir-cuit wire, oa short to the (01 cir-cuit wire in the lll circuit wirobetweon the ABS control unitand th. appropriate whasl sen-sot.. Roplace the rpp.opriatc whe6lSensor.
ls the resistance OK?
/Fronr:750 - r,050 o (20"C,68"F\
\Rear: 950 -'1,450 O (20"C, 68'F,
Chock lor a short 10 power in thewheel sensoa ciacuil:1. Reconnect the ABS control unit26P connector.2. Start the engine.3. Measure the voltage betlveenthe ABS control unit 26P con-nector appropriate wheel sen-sor (0) circuit terminal andbody ground (see table).
Ropair lhort to pow.r in the l0lot 11) circuit wiro between theABS control unit and the appro-priate whool sen6or.
ls there 4 V or more?
Check for a short to body groundin the whoal s.n3or cilcuit:1. Disconnect the ABS controlunit 26P connector.2. Check lor cont;nuity betweenthe ABS control unit 26P con-nector appropriate wheel sen-sor {0) circuit terminal andbody ground {se6 table).. Ropair short to body g.ound inth6 {01 or {1} circuit wirebotweon th6 ABS cont.ol unitand tho appropriato wheol son-aot.. Roplace tho appropriate wheelsensot.
DTC 11 - 18: Wheel Sensor
NOTE: The ABS indicator comes on only when the drive wheels are turning and signal disturbance is detected, Therefore, test-drive the car at a speed of 12 mph (20 km/h) or more after turning the ignition switch from OFF to ON l), and if the ABS indica-tor does not come on, the svstem is OK.
RLl (LT BLUI FRl IGRN/BLKI
Wire side of female terminals
NOTE: Judgement value for short
NO
NOTE:. Normalvoltage: Approx. 2 V.0 V: Replace the ABS control unit.. 4 V or more indicates a shon to power.
NO(cont'dl
ABS CONTNOL UNIT 26P CONNECTOR
RROIBLU/YEL}
RRT IGRN/YELI
FLO(BRN/WHTI
FLl IGFN/ORN}
DTCAppropriate Terminal
{0}srDE(1)S|DE
11, l2lRight-front)No.8: FnoNo.21: FR1
13, 14 (Left-front)No. 10rFLoNo. 23: FLl
15, 16 (RightreadNo.4: RRoNo.17: RR1
17, l8 (Lsft-rear)No.6: RLoNo.19: RL1
(To page 19-46)
19-45
www.emanualpro.com

DTC 31 - 38: Solenoid
ABS CONTROL UNIT 22P CONNECTOR
Wire sade of female terminals
Wire side of female terminals
ABS CONTROL UNIT 26P CONNECTOR
FL.OUT IYEL/8LKI
DTCAppropraateConnectorTerminal
31: FR'lN22PNo. 1
32: FR OUT22PNo. 12
33: FL lN22PNo. 11
34: FL OUT22PNo.10
35:RR-lN26PNo.13
36: RR-OUT22PNo.21
37: RLIN26PNo.25
38: RL-OUT26PNo. 12
RL.OUT {YELI
FL.OUT IYEL/BLKI
DTCAppropriateTerminal
31: FR lNNo. 2i SCOM
32: FR-OUTNo. 2: SCOM
33: FLINNo.1:PCOM
34: FL-OUTNo. 1:PCOM
35:RRINNo. 1: PCON4
36: RR-OUTNo. 1: PCON4
37rRL-lNNo. 2: SCOM
3a: RL-OUTNo. 2: SCOM
RL.OUT {YELI
- With the ignition switch ON{lD, tho ABS indicator doesnot go off, or the ABS indic.-lor comes on whil6 ABS istunctioning.- With th€ SCS service connoc-tor connoctcd {sce page 1$381,DTCa 31 - 38 ars indicatsd.
Check for a 3hori to power in th€solenoid ci.cuit:1. Disconnect the ABS controluntr tlr ano zbr connectors_2. Start the engine.3. Measure the voltage betweenthe appropriate ABS controlunit connector solenoid circuitterminal and body ground (see
table).
R€pair short to power in theapprop.iato solenoid circuit wirebetwe€n the ABS control unitand the modulator unh.
ls there baRery voltage?
Chock for a short to body groundin the sol€noid circuit:Check for continuity between theappropriate solenoid circuit termi-naland body ground (see table).
. Ropair short to body ground inthe appropriato solenoid circuitwire betwoon the ABS controlunit and the modulator unit.. Replace the modulator unit.
ls there continuity?
Check the ABS control unit:1. Turn the ignition switch OFF.2. Connect the ABS control unit22P and 26P connectors.3. Connect the SCS service con-nector.4. Turn the ignition switch ON (ll).5, Measure the voltage betweenthe appropriate ABS controlunit 26P connector COM circuitterminal and body ground (seetable).
Check tor loose ABS control unitconnectors. ll nece$ary, substi-tut€ a known-good ABS controlunit and recheck.
ls there approx. 3 V7
PCOM
(To page l9-48){GRN/WHTI
19-47
www.emanualpro.com

Check fo. a short to power in thaPCOM, SCOM circuhi1. Start the engine.2. Measure the voltage betweenbody ground and ABS controlunit 26P connector terminalsNo. I and No.2 individually.
'Repair short to powor in thsFCOM circuit wiro botwoon th€ABS control unit and the under-hood ABS tuse/r.lay box.. Repeir 3hort to power in thoPCOM or SCOM circuit wirebetwegn tho ABS control uniiand ths modulator unh,. R.placo tha modulatoi unit.(Shon to power in.ido th6 unitl
ls there 8 V or more?
Tu.n tho ignhion switch OFF andconnect thc SCS 3orvice connec-tor. Then turn thc ignition switchON (lll and measure tha voltagobotween the PCOM .nd SCOMtsrminal3 and body gJound. Itther6 is 0 V, .epleco tho ABS con-trol unit.
ABS CONTROL UNIT 26P CONNECTOR
PCOM
Wire side of temale terminals
NOTE: 8 V or more indicates a short to
(GRN/WHTI SCOM
www.emanualpro.com

Gonnector ldentification and Wire Harness Routing
How to ldentity Connectors:
ldentification numbers have been assigned to all connectors, The number is preceded by the letter "C" for connectors.
"G" for ground terminals or "T" for non-ground terminals.
Location
HarnessEngine CompartmsntDashboardOthers lFloor, Door,
8oof, Tailgate)
Starter cableT1, T2 and @
Battery ground cableG1 and O
Engine ground cableT3
Transmission ground cableT4
G3
Engine wire harnessC101 through C137
T101 and T102
G101
Engine compartment ware harnessC201 through C218
G201 and G202
Under-hood ABS fuse/relay box
wire harness
t5ano9
Main wire harnessC301 through C309
C351 through C361
C401 through C447
G401 and G402
Dashboard wire harnessC501 through C524 (C525)
G501
Left side wire harnessC551 through C581
G551, G552 and G553
Right side wire harnessC601 through C605
lnterior wire harnessC701 through C703
Rear bumper wire harnessC641 through C643
Heater sub-harnessC731 through C740
Secondary heated oxygen sensor
sub-harness
C721 through C722
Combination switch sub-harnessC751 through C760
Driver's door wire harnessC661 through C667
Front passenger's door wire harnessC6Tl through C676
Left rear door wire harnessC681 through C684
Right rear door wire harnessC69'l through C694
Rear wire harnessC611 through C520
Tailgate wire harnessC631 through C634
G631
SRS main harnessC801 through C808
G801
High mount brake light sub-harnessC651 through C653
Fuel tank oressure sensor sub-harnessC645 through C647
www.emanualpro.com

Connector ldentification and Wire Harness Routing
Engino Wire Harness
Connecto; or
Terminal
Number of
CavitiesLocationConneqts toNotos
c101
c102
c103
c 104
c105
c105
c106
c 107
c 108
c 109
c]10
c1l'l
c112
c113
c't 14
cl16
cl16
c117
c118
c119
c120
c121
c't22
c't23
c't25
cl26
cl27
cr 28
cl29
c130
c131
c132
c 133
c134
c134
c135
c 136
10
6
1
2
1
2
1
10
20
31
16
22
l0
l0'14
14
1
Left side of engine compartment
Left side of engine compartment
Middle of engine
Middle of engine
Left side of engine compartment
Left side of engine compartment
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Right side of engine
Middle of engine
Behind right kick panel
Under right side of dash
Under right side of dash
Under right side of dash
Under right side of dash
Under right side of dash
Right side of engine
Right side of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Left side of engine compartment
Middle of engine
Middle of engine
Main wire harness (C304)
Main wire harness (C305):'97 - 98 models
No. 1 fuel injector
Crankshaft speed fluctuation (CKF) sensor
Alternator
Alternator
Engine oil pressure switch
No.2 fuel injector
Evaporative emission (EVAP) purge
control solenoid valve
No. 3 fuel injector
No. 4 fuel injector
Primary heated oxygen sensor(Primary HO2S) (sensor 1)
Radiator fan switch
Coolant temperature sending unit
Engine coolant temperature (ECT) sensor
Mainshaft speed sensor
Lock-up control solenoid valve
Back-up light switch
Shift control solenoid valve
Linear solenoid valve
Countershaft speed sesnsor
Starter solenoid
Distributor
Junction connector
PCM
ECIWPCM
ECM/PCM
ECM/PCM
Main wire harness (C,|:}1)
IVT gear position switch
Vehicle speed sensor (VSS)
Throttle position (TP) sensor
MAP sensor
ldle air control (lAC)valve
lntake air temperature (lAT) sensor
Junction connector
Junction connector
Power steering pressure (PSP) switch
Junction connector
Knock sensor (KS)
A/r
USA
Canada
Alr
AlT
M/'r
Afi
'97mooel
'97 model'98 - 00
mooets
'99 - 00
models
T101
r102
Left side of en0ine companment
Right side of engine compartment
Alternator
Under-hood fuse/relay box
G101Middle of engineEngine ground, via engine wire harness
23-14
www.emanualpro.com