Page 536 of 1395

Description
Electronic Control System (cont'd)
Descending Control
When the PCM determines that the vehicle is going down a hill in E and @ positions ('97 - 98 models). and in @ posi-
tion {'99 - 00 models), the shitt-up speed from 3rd to 4th gear and from 2nd to 3rd (when the throttle is closed) becomes
faster than the set speed for flat road driving to widen the 3rd gear and 2nd gear driving areas. This, in combination with
engine braking from the deceleration lock-up, achieves smooth driving when the vehicle is descending. There are three
descending modes with different 3rd gear driving areas and 2nd gear driving areas according to the magnitude of a gradi-
ent stored in the PCM. When the vehicle is in 4th gear, and you are decelerating when you are applying the brakes on a
steep hill, the transmission will downshift to 3rd gear, When you accelerate, the transmission will then return to higher
gear.
2ND - 3RD 3RD - 4TH
o50
F
DESCENDING MODE: Downshift Schodule
- : FLAT ROAD MODE
----'-----' I GRADUAL DESCENDING MODE
- - - - - : MEDIUM OESC€NOING MODE
. . ... : STEEP DESCENDING MODE
62 mph Vehicle sp€ed1100 km/hl
Deceleration Control
When the vehicle goes around a corner, and needs to decelerate first and then accelerate, the PCM sets the data for deceleration
control to reduce the number of times the transmission shifts. When the vehicle is decelerating from speeds above 27 mph(4i| km,ih), the PCM shifts the transmission from 4th to 2nd earlier than normal to cope with upcoming acceleration,
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Page 572 of 1395

Troubleshooting Procedures
Checking ths Diagnostic Trouble Code (DTC)
with an O8D ll Scan tool or Honda PGM Tsster
When the PCM senses an abnormality in the input or output systems, the El ('97 - 98) or E ('99 - O0) indicator light in thegauge ass€mbly will blink. When the 16P Data Link Connector (DLC) {located under the dash on the passenger's side) is
connected to the OBD ll Scan Tool or Honda PGM Tester as shown, the scan tool or tester will indicate the Diagnostic
Trouble Code (DTC) when the ignition switch is turned ON(ll).
HONDA PGM TESTER olOBD II SCAN TOOL
lf the E or E indicator light or the MIL has been reported on, or if a driveability problem is suspected, follow this proce-
dure:
1. Connect the OBD ll Scan Tool (conforming to SAE J1978) or Honda PGM Tester to the 16P DLC. (See the OBD ll ScanTool or Honda PGM Tester user's manual for specific instructions. lf you are using the Honda PGM Tester, make sureit is set to the SAE DTC Wpe).2. Turn the ignition switch ON (ll), and observe the DTC on the screen
3. Record allfuel and emission DTCS, A,,/T DTCS, and freeze data.
4. lf there is a fuel and emissions DTC, first check the fuel and emissions system as indicated by the DTC (except for DTCP0700). DTC P0700 means there is one or more Ay'T DTC, and no Droblems were detected in the fuel and emissionscircuit of the PCM.
5. Wire down the radio station presets.
6. Reset the memory with the PGM Tester o. by removing the BACK UP fuse in the under-hood fuse/relay box for morethan 10 seconds.
7. Drive the vehicle for several minutes at speeds over 30 mph (50 km/hr), and then recheck for DTCS. lf the A/T DTCreturns, 9o to the Symptom-to Component Chart on pages 14-60 and 14-61 for the '97 models, and pages 14-62 and14-63 for '98 - 00 models. lf the OTC does not return, there was an intermittent problem within the circuit. Make sureall pins and terminals in the circuit are tight, and then go to step 8.8. Reset the radio Dreset stations, and set the clock.
DATA LINK CONNECTOR {16PI
[ -=.r,
ili,i /i,
v,., i
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Page 575 of 1395
PCM Reset Procedure
'1. Turn the ignition switch off
2. Remove the BACK UP fuse (7.5 A) from the under-hood fuse/relay box for 10 seconds to reset the PCM.
NOTE:
. Disconnecting the BACK Up fuse also cancels the radio preset stations and clock setting Make note of the radio
presets before removing the fuse so you can reset them
. The PCM memorv can also be cleared by using the OBD ll Scan Tool or Honda PGM Tester'
UNDER.HOODFUSE/RELAY BOX
Final Proceduro
This procedure must be done after any troubleshooting.
1. Turn the ignition switch OFF.
2. Reset the PCM.
3. Disconnect the OBD ll Scan Tool or Honda PGM Tester from the Data Link Connector (16P), or remove the special tool
from the Service Check Connector (2P).
4. Turn the ignition switch ON (ll), and set the radio presets and clock setting'
5, To verify that the problem is repaired. test-drive the vehicle for several minutes at speeds over 30 mph (48 km/h).
BACK UP IRADIO} {7.5 AI FUSE
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Page 576 of 1395
Symptom-to-Component Chart
Electrical System -'97 Model
DTC*: The DTc in parentheses is the code the loa indicator right indicates when the Data LinkConnector is connected to the Honda pGM Tester.
DTC*E Indicatol
LightMILDetection ltemPage
P 1753
(1)BlinksONLock up control solenoid valve A(see page 14-64)
P1758
\21
B linksONLock-up control solenoid valve B(see page 14-66)
P 1705
(5)BlinksONA,/T gear position switch (short to ground)(see page 14-68)
P1706
(6)OFFONA,/T gear position switch {open)(see page 14-70)
P0753
\11
B linksONShift control solenoid valve A(see page 14-72)
P0758
(8)BlinksONShift control solenoid valve B(see page 14-74)
P0720
(9)BlinksONCountershaft speed sensor{see page 14-76)
P0715
(15)B linksONMainshaft speed sensor(see page l4-78)
P17 68( 16)
BlinksONLinear solenoid(see page 14-80)
P0740
{40)
OFFONLock-up control system(see page 14-82)
P0730
(41)OFFONShift control system(see page 14-84)
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Page 578 of 1395

Symptom-to-Component Chart
Electrical System -'98 - 00 Models
DTC*; The DTC in the parentheses is the code the E or E indicator light indicates when the Data LinkConnector is connected to the Honda pGM Tester.
DTC*
Et Indicatol
Lighr (98)
E Indicator
Light ('99 - 00)
MILDetestion ltomPage
P1753
(1)BlinksONLock-up control solenoid valve A{see page 14-93)
P1758
(21BlinksONLock-up control solenoid valve B(see page 14-96)
P1705(5)BlinksONA,/T gear position switch (shon to grounol(see page 14-99)
P1706(6)OFFONA,/T gear position switch (open)(see page 14-103)
P0753
(71Blin ksONShift control solenoid valve A(see page 14-106)
P0758
(8)BlinksONShift control solenoid valve B(see page 14-109)
P0720
(9)BlinksONCountershaft speed sensor{see page 14-112)
P0715
{15)
BlinksONMainshaft speed sensor(see page 14-114)
P1768
(16)BlinksONLinear solenoid(see page 14-117)
POl 40(40)OFFONLock-up control system(see page 14-119)
P0730
(41)OFFONShift control system(see page 14-121)
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Page 580 of 1395

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 ()?
To page 14 65
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Page 582 of 1395

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?
To page 14-67
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Page 584 of 1395

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
To page 14-69
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