PGM-FI System
Vehicle Speed Sensor (VSSI {cont'd}
'98 - 00 models:
ECM/PCM CONNECTORS
B t25Pl
NOTE (4WD): Do not use the engine to turnthe front wheels with the rear wheels on theground. The 4WD system will engage andthe vehicle will suddenly lurch forward.
Wire side of female terminals
- The MIL ha3 been reDoned on.- DTC P0500" or P0501*1 i33torod.
Probl6m verification:1. Test-drive the vehicle.2. Check the vehicle speed withthe scan tool,
Intermittont failu.e, svstem is OKat thk time. Check for poor con-nection! or loose wiros at C129lvss) .nd ar the EcM/PcM.
ls the correct speed indicated?
Check for rn open in the ECM/PCM:l Turn the ignition switch OFF.2. Elock the rear wheels and setthe parking brake.3. Jack up the front oI the vehicleand support it with satetystands.4. Turn the ignition switch ON {ll}.5. Block the right front whoel andslowly rotate the lett front
6. Measure voltage betweenECM/PCM connector termi-nals 820 and C23.
Substitute a known-good ECM/PCM and rochock. ll symptom/indicetion 9063 away, .oplace th€origin.l ECM/PCM.
Does the voltage pulse between0 V and 5 V or battery voltage?
Check for a short in the ECM/PCMI1. Turn the ignition switch OFF.2. Disconnect ECM/PCM connector C 131P).3. Turn the ignition swilch ON {ll).4. Block the right front wheeland slowly rotate the left front
5. Moasure voltage between ECM/PCM connector terminals 820and C23.
Sub.titute a known-good ECM/PCM and rschock. It rymptom/indication goos .w.y. replecerhe original ECM/PCM.
Does the voltage pulse betlveen0 V and 5 V or battery voltage?
- R.pair short in the wirobetwe€n the ECM/PCM lC23).nd tho VSS.- Roprir open in th6 wirebotweon the ECM/PCM lc23land th6 vss.- It wirc is OK, te3t ihe VSS(!€e soetion 23).
B (25P)
1
*2:Mft
1-136
www.emanualpro.com
ldle Control System
System Description
The idle speed of the engjne is controlled by the ldle Air Control (lAC) Valve'
The valve changes the amount of air bypassing into the intake manifold in response to electric current controlled by the
ECM/PCM. When the lAc valve is activated, the valve opens to maintain the proper idle speed.
YEL/ From PGM'FI
BLK TMAIN RELAY
VARIOUSSENSORS
4.
IAC VALVE
INTAKE MANIFOLD
After the engine starts, the IAC valve opens for a certain time. The amount of air is increased to raise the idle speed
about 150 - 300 rpm.
when the cootant temperature ts row, the lAc valve is opened to obtain the proper fast idle speed The amount o{
bvoassed air is thus controlled in relation to the engine coolant temperature
When the idle speed is out o{ specification and the scan tool does not indicate Diagnostic Trouble Code (DTC) P0505
or P1508, check the following items:
. Adjust the idle speed (see page 11-169, 170)
. Air conditioning signal (seepagell-1551
. ALT FR signal (see page 1l-159)
. Starter switch signal (see page 11-16'1)
. A,/T gear position signal (see section 14)
. PSP switch signal (seepagell-162)
. Brake switch signal (see page 11-165)
. Fast idlethermovalve (see page'11 168)
. Hoses and connecttons. IAC valve and its mounting O-rings
lf the above items are normat, suDslitute a known-good IAC valve and readjust the idle speed {see page 11-169, 170)
lf the idle speed still cannot be adjusted to specification (and the scan tool does not indicate DTC P0505 or Pl508)
after IAC valve reolacement, substitute a known-good ECM/PCM and recheck lf symptom goes away' replace the
original ECM/PCM.
11-149
www.emanualpro.com
Removal
!@@ Make sure the lifts, i8cks. and safety stands
are placed properly {see section 1}.
1. Raise the front of the vehicle, and support it with
safety stands (see section 1).
2. Set the parking brake, and block both rear wheels
securely.
3. Drain the manual transmission fluid Reinstall the
drain plug with a new sealing washer.
4. Disconnect the heated oxygen sensor (HO2S) con-
nector.
SELF.L(rcKNGNUTReplace.
SELF-LOCKI'{GNUTReplac€.
5. Remove exhaust oipe A.
6. Make reference marks across the propeller shaft
and the transfer assembly flanges'
Separate the propeller shaft from the transfer
assembly flanges,
Remove the rear stiffener, then remove the transfer
assembly.
NOTE: While servicing the transfer assembly, do
not allow dust or other foreign particles to enter the
transmission.
7.
REFEREI{CE i'ARKS
Replace.
Replace.
13-5
www.emanualpro.com
Description
Electronic Control System (cont'dl
Grade Logic Control System
How it works:
The PCM compares actual driving conditions with memorized driving conditions, based on the input from the vehicle speed
sensor, the throttle position sensor, the barometric pressure sensor ('98 model). the engine coolant temperature sensor, the
brake switch signal, and the shift lever position signal, to control shifting while the vehicle is ascending or descending a
slope, or reducing speed.
SIGNALS DETECTED
Driving Rcsisl.nce
Judgemont ot Controlling Aroa
. Normal Modo {Flrt ro.d mode}. Ascending Mode. Deacending Mode. Deceleration Mode
14-14
www.emanualpro.com
PCM CONNECTOR B (25P) lcont'd)
PCM CONNECTOR C {31PI
PCM CONNECTOR D II6PI
Terminal NumbelSignalDescriptionMeasuring Conditions/Terminal voltage
811SHBShift control solenoid valve B
control
In E, E position, in 1st and 2nd gear in -q,
Er position: Battery voltage
In B position, in 3rd gear in qd, q:l,in atn
gear in D. position: 0 V
812ILUlnterlock controlWhen ignition switch is ON (ll), brake pedal
deDressed and accelerator oedal released:0 V
B13D4 INDD4 Indicator light controlWhen ignition switch is first turned ON (ll): 6 V
or more for tlvo seconds
In lDll position: 6V or more
814NMSGMainshaft speed sensor ground
815NMMainshaft speed sensor signal
InpuI
Depending on engine speed: Pulsing signal
When engine is stopped: 0 V
816ATP RAy'T gear position switch Eposition signal input
In E position; OV
In other than E position: Battery voltage
817ATP 2Ay'T gear position switch E posi-
tion signal input
InEposition:0V
In other than E position: Battery voltage
B18ATP 1A/T gear position switch El posi-
tion signal input
InEposition:0V
In other than E position: Battery voltage
819 to 821Not used
B 22NCSGCountershaft speed sensor ground
NCCountershaft speed sensor signal
Inpur
Depending on vehicle speed: Pulsing signal
when vehicle is stooped: 0 V
824ATP D4A/T gear position switch iql posi-
tion signal input
In E position: 0V
In other than lgal position: Baftery voltage
825ATP NPAy'T gear position switch E and
N position signals input
In E and E positions: 0V
In otherthan @ and ffi positions:5 V
Terminal NumberSignalDescriptionMeasuring Conditions/Terminal Voltage
SCSService check signalWith ignition switch ON (ll) and service check
connector open: 5 V
With ignition switch ON (ll) and service check
connector connected with special tool: 0 V
c10VBUBack-up power system(under-hood Fuse 47)
Always battery voltage
Terminal NumberSignalDescriptionMeasuring Conditions/Terminal Voltage
STOP SWBrake switch signal inputBrake pedal pressedr Battery voltage
Brake pedal released: 0 V
14-49
www.emanualpro.com
1?
4678
CavityWire
ColorTest CondhionTost: Desired RosultPossible Cause(lf result is not obtainedl
1WHT/BLU
lgnition switch turned
to ACC (l), ignition key
pushed all the way in
Check for voltage to ground:
There should be battery voltage.
Blown No. 48 {30 A} fuse in the
under-hood fuse/relay box
Blown No.33 (7.5 A) fuse in the
under-dash fuse/relay box
Faulty steering lock assembly
{key interlock solenoid)
An open in the wire
YEL
lgnition switch ON (ll)Check for voltage to ground:
There should be battery voltage.
Blown No.25 (7.5 A) fuse in the
under-dash fuse/relay box
An open in the wire
YEUBLK
lgnition switch ON (ll)Check for voltage to ground:
There should be baftery voltage.
Blown No. 25 (7.5 A) fuse in the
under-dash fuse/relay box
Faulty shift lock solenoid
An open in the wire
4BLKUnder all conditionsCheck for continuity to ground:
There should be continuity.
. Poor ground (G401)
. An open in the wire
5WHT
lgnition switch turned
to ACC (l), ignition key
pushed all the way in
Check for voltage to ground:
There should be battery voltage.
Blown No.48 (30 A) fuse in the
under-hood fuse/relay box
Blown No. 33 (7.5 A) fuse in the
under-dash fuse/relay box
Faulty steering lock assembly(key interlock switch)
An open in the wire
BLI(BLU
Shift lever in ECheck for continuity to ground:
There should be continuity,
Faulty Ay'T gear position switch
Poor ground (G101)
An open in the wire
8WHT/BLK
Shift lever in @ and
pulled toward steering
wneel
Check for continuity to ground:
There should be continuity.
Faulty park pin switch
Shon to ground
Shift lever in ECheck for continuity to ground:
There should be no continuity.
Wire side of female terminals
Reconnect the interlock control unit 8P connector.
14-145
7WHT/RED
lgnition switch ON (ll)
and brake pedal
presseo
Check for voltage to ground:
There should be 1 V or less.
Faulty brake switch
Faulty throttle position (TP)
sensor
Faulty PCM
An open in the wire
Faulty interlock control unit
lgnition switch ON (lll,
brake pedal and accel-
erator pedal pressed at
the same time
Check for voltage to ground:
There should be baftery voltage,
www.emanualpro.com
Road Test
NOTE: Warm up the engine to normal operating temperature (the radiator tan comes on).
1. Before testing, check the transmission fluid level, see page 14-160.
2. Apply the parking brake and block the wheels. start the engine, then shift to E {'97 - 98) or E {'gg - 00) position
while pressing the brake pedal. Press the accelerator pedal and release it suddenly. The engine should not stall.
3. Repeat same test in E position ('97 - 98 models).
4. Test-drive the vehicle on a flat road in the E or E position. Check that the shift points occur at approximate speeds
shown on a flat road. Also check for abnormal noise and clutch slippage.
Throttle position sensor voltage represents the throttle opening. Monitor it with the Honda PGM Tester or as follows:
a. Unbolt the PCM for road testing; reJer to page 14-58.
b. Set the digital multimeter to check throttle position sensor voltage between these terminals on the PCM:
. '97 Model: Between terminals D'! (+) and A9 (-) or A22 {-}
. '98 - OO Models; Between terminals C27 (+) and 820 (-) or 822 {-)
BACKPROBE ADAPTER
BACKPROBE SETorsAz - 001moA(two roquircdl
STACKING PATCH
CORD
DIGiTAL MULTIMETER
{Comm€rcirllY .vailablc}KS-AHM-32-003,or equival.nt
'97 Model:PCM CONNECTORS
'98 - 0O Models:
A l32Pt
Wire side of female terminals
PCM CONNECTORS
B {25Pt c l31P}
(cont'd)
LGl (BRN/BLK)
'. //B 1 l'o ti , jl. to a 2r / / 11111t1.t nait la t1 t213tr / t6t, tl / / / / 1 3 / 10n v
t-'a:IM-&E -Llfiffi-fl)\"".'E
Wire side ot female termanals14-157
www.emanualpro.com
Road Test
(cont'd)
lgrr or E Position:
Upshift
NOTE:
. Lock-upON:The lock-up control solenoid valve A turns ON.. Lock-up OFF: The lock-up control solenoid valve A turns OFF.
4. Accelerate to about 35 mph (57 km/h) so the transmission is in 4th. then shift from E or E position to E position.The vehicle should immediately begin slowing down from engine braking.
5. Check for abnormal noise and clutch slippage in the following positions.
E {1st Gear) Position
Accelerate from a stop at full throttle, Make sure there is no abnormal noise or clutch slippage.Upshifts should not occur with the shift lever in this position.
E (2nd cear) Position
Accelerate from a stop at fuI throttre. Make sure there is no abnormar noise or crutch srippage.Upshifts and downshifts should not occur with the shift lever in this position.
E (Reverse) Position
Accelerate from a stop at full throttle. and check for abnormal noise and clutch slippage.
6. Test in E (Park) Position
Park the vehicle on slope (approx. 16"), apply the parking brake, and shift into E position. Release the brake; the vehi-cle should not move.
Throftle OpsningUnit of sps€dlsi + 2nd2nd * 3rd3rd + ilthLock-up ON
Throttle position sensor
voltage: 0.75 V
mph9-1220-2328-33
km/h15-1945-5334-40
Throttle position sensor
voltage; 2.25 V
mph22-2643-49oz - ott68-74
km/h35-4169-7999 - 108109 - 118
Fully-opened throttle,
Throttle position sensor
voltage: 4.5 V
mph37-43101 - 11190 - 101
k-/h60-69111 - 124163 - 179145 - 163
Downshift
Throttle OpeningUnit ot speedLock-up OFFi{th + 3rd3rd * 2ndznd + lst
Fully-closed throttle,
Throttle position sensor
voltage; 0.5 V
mpn19-231A - 2'l6 - 10 {3rd - 1st)
km/h5t-5D29-3410 - 15 (3rd * 1st)
Fully-opened throttle,
Throttle position sensor
voltage: 4,5 V
mph88-9986-9657 -6426-32
km/h142 - 't59138 - 15492 - 10342-51
14-158
www.emanualpro.com