Page 525 of 2189

Emission Control System
Exhaust Gas Recirculation (EGR) System (D16Y5 engine with GWI (cont'dl
lTl49il T_he scan tool indicates Diagnostic Trouble Code (OTC) P1491: A malfunction in the Exhaust Gas Recirculation- lEgh) svstem.
CvT lM/T see page 1l-2611:
J
EGR VALVELIFT SENSOR#16 HOSE
PUMP/GAUGE,0- 30 in.HsA973X-041-XXXXX
EGRVALVE
The MIL has been reoorted on.DTC P1491 is stoled.
Problem verification:1. Do the ECM/PCM Reset Proce-du re.2. Connect the SCS service con'
3. Start the engine. Hold theengine at 3,000 rpm with noload {in Park or neutral) untilthe radiator fan comes on,4. Drive the vehicle on the roadfor approx. 10 minutes. Try tokeep the engine speed in the1,700 - 2,500 rpm range.
Intermittonl failure, system is OKat this time. Check for Door con-nections or loose wires at, C144{EGR velve} and ECM/PCM.
ls DTC P l49l indicated?
Check fo. vacuum to ihe EGR
1. Disconnect the No. 16 hose fromthe EGR valve.2. Connect a vacuum pump/gauge to the hose.3. Start the engine and let it idle.
ls there any vacuum?
Check tor a malfunction in theEGR control solenoid valve:'1. Disconnect the EGR controlsolenoid valve 2P connector,2. Becheck the No. 16 hose for
Check vacuum hose routing o,the entire EGR svstem. lf hoserouting is OK, replac€ the EGRcontrol solenoidvalv6.
ls there any vacuum?
Substitute a known-good ECM/PCM and recheck. It symptom/indicalion goes away, replacethe original ECM/PCM.
(To page 11 257)
11-256
Page 530 of 2189

\JExhaust Gas Recirculation System (D16Y5 engine with M/T)
M/T:
EGR VALVE 6P CONNECTOB (C14'rl
G10lIBLK}
1
a
PNK
IE.EGRI
Wi16 side of male terminals
I
sG2{GRN/BLK}
vcc2{YEL/BLU)
- Th6 MIL ha3 b€on reponed on.- DTC Pl,{tl is 3tored.
Prcblem verification:1. Do the ECM Reset Procedure.
2. Connect the SCS service con_nector.3. Start the engine. Hold the
engine at 3,000 rpm with no
load (transmission in neutral)
untilthe radiator fan comes on.
4. Drive the vehicle on the road
for approx. 10 minutes. Try to
keep the engine speed in the
1,700 - 2,500 rpm range.
lnlermittont tailure, svalem is OK
at thi3 tim6. Check foi Poor con'
nections or looso wiro3 at Cl/K
IEGR valvsl and ECM.
ls DTC P1491 indicated?
Check tor a malfunction in the
EGR valv6:1. Turn the ignition switch OFF.
2. Disconnect the EGR valve 6P
connector.3. Stanthe engine and let it idle
4. Measure voltage between the
EGR valve 6P connector termi'
nals No.4and No.6.
Check the EGR valve:1. Turn the ignition switch OFF2. Turn the ignition switch ON lll).3. Measure voltage between theEGR valve 6P connector termi
nals No.2 and No.3.
ls there battery voltage?
Substitute a known-good ECM
and recheck. It symptom/indica_tion goes away, replace th€ origi-
nal ECM.
ls there approx.5V?
(To page 11-262)
Page 719 of 2189
SERVICE CHECK CONNECTOR
LOCK -UP CONTROLSOLENOIO VALVEASSEMELY
RED WHT
tlll'
IT
tl
ll
Lo-l
MAINSHAFTSPEED SENSOR
TBRNiBLK
I
I
I-
G 101
NCSG ILS - ILS + ISH A ISH B ltc A ltc B
SHIF'CONTROLSOTENOID VALVEASSEMEI-Y
PCM Terminel Locations
14-41
Page 721 of 2189

I
PCM CONNECTOR B {25P1 {cont'dl
Terminal NumberSignalDescriptionMeasuring Conditions/Terminal Vohage
811SHBShift control solenoid valve B
control
In 1st gear and 2nd gear in -q1, q11 position,
and in E] position: Battery voltage
In 3rd gear and 4th gear in lD.J, [Dr- position: 0 V
B't2SLUInterlock controlWhen ignition switch is ON (ll), brake pedal
deoressed and accelerator Dedal released: 0 V
813D4 INDD4 Indicator light controlWhen ignition switch is first turned ON (ll):
Battery voltage for two seconds
In E position: Baftery voltage
B't 4NMSGMainshaft speed sensor groundAlways: 0 V
E tcNMMainshaft speed sensor signal
input
Depending on engine speed: Pulsing signal
When engine is stopped: 0 V
816ATP RAy'T gear position switch Eposition signal input
InE position: 0V
In other than E position: Battery voltage
817ATP 2A/T gear position switch E posi-
tion signal input
InE position: 0V
In orher than E position: Battery voltage
818 to 821Not used
s22NCSGCountershatt speed sensor groundAlwaysr 0 V
B 23NCCountershaft speed sensor signal
input
Depending on vehicle speed: Pulsing signal
When vehicle is stopped: 0 V
B 24ATP D4Ay'T gear position switch lor posi-
tion signal input
InEposition:0V
In other than 6 position: 5 V
ATP NPA,/T gear position switch E and
N position signals input
InE and E positions: 0V
In otherthan E and N] positions: Battery voltage
PCM CONNECTOR C {31P)
Terminal NumberSignalDescriptionMeasuring Conditions/Terminal Voltage
Cl to C6- see section 11 -
c1Service check signalWith ignition switch ON (ll) and service check
connector oDen; 5 V
With ignition switch ON (ll) and service check
connector connected with sDecial tool: 0 V
C8 to Cg- see section 11 -
c10VBUBack-up power systemAlways battery voltage
C11 to C31- see section '11 -
PCM CONNECTOR D (16P}
Terminal NumberSignalDescriptionMeasuring Conditions/Terminal Voltage
Dl to D4- see section 11 -
D5STOP SWBrake switch signal inputBrake pedal depressed: Battery voltage
Brake pedal released: 0 V
D6 to D16- see section 1 l -
14-43
Page 724 of 2189

PCM Terminal Voltage/Measuring Conditions ('99 - 00 Models)
A/T Control System
The PCM terminal voltage and measuring condjtions are shown for the connector terminals that are related to the A//T con-trol system, The other PCM terminal voltage and measuring conditions are described in section ,11.
PCM Connoctor Tgrminrl Locations
PCM CONNECTOR A {32PI
PCM CONNECTOR 8 (25P}
Terminal NumbelSignalDescriptionM€asuring Conditions/Terminal Voltage
A105L5Service check signalWith ignition switch ON (ll) and service check
connector open: Approx, 5 V
With ignition switch ON (ll) and service check
connector connected with sDecial tool: 0 V
A14D4 INDE indicator light controlWhen ignition switch is first turned ON (ll):
ApDrox. 10 V for two seconds
In E position: Approx. 1O V
428ILUInterlock ControlWhen ignition switch ON (ll), brake pedal
depressed, and accelerator pedal rereaseo:
Battery voltage
A.32STOP SWBrake switch signal inputBrake pedal depressed: battery voltage
Brake oedal released:0 V
Terminal NumberSignalDescdptionMeasuring Condhions/Torminal Voltag6
B1!GP1Power supply systemWith ignition switch ON (ll): Battery voltage
With ignition switch OFF: 0 V
PGlGround
B8LS AMLinear solenoid power supply
negative electrode
With ignition switch ON (ll): Pulsing signal
B9IG P2Power supply systemWith ignition switch ON (ll): Baftery voltage
With ignition switch OFF: 0 V
810PG2G rou nd
917LS APLinear solenoid power supplypositive electrode
With ignition switch ON (ll): Pulsing signal
B 20Ground
VBUBack-up power supplyAlways battery voltage
822Ground
\
14-46
Page 727 of 2189

Chocking th€ Diagnostic Trouble Code (DTCI
with the Servico Check Conneqtor and Sp€cialTool
When the PCM senses an abnormality in the input or output systems, the @ indicator light in the gauge assembly will blink
When the Service Check Connector (locat€d under the dash on the passengsr side) is connected with the special tool as
shown, the E indicator light will blink the Diagnostic Trouble Code (DTC) when the ignition switch is turned ON (ll).
When the E indicator light has been reported on, connect the Service Check Connector with the special too'.
Then turn ON (ll) the ignition switch and obssrve the E indicator tight.
CONNECTOBSERVICE CHECKCONNECTOR I2PI07PAZ -0010100
Codes 1 through 9 are indicated by individual short blinks, Codes 10 and above are indicat€d by a sories of long and short
blinks. One long blink equals 1O short blinks. Add the long and short blinks together to determine th€ code. After deter-
mining the code, refer to the electrical system Symptom-to Component Chart on pages 1+52 and 1+53 for'96 - 98 mod-
els, and 14-54 and 14-55 for the '99 - 00 models.
S€r DTC 1
s.. DTC 2
Long blinkShort blink lfiYa tim.!,
S€c DTC 15
(cont'd)
GAUGE ASSEMBLY
Short blink loncel
14-49
Page 729 of 2189
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 luse so you can reset them
. in" gCfU memory can also be cleared by using the OBD ll Scan Tool or Honda PGM Tester'
Final Procedure
NOTE: 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, or remove the special tool from
the Service Check Connector.
4. Turn the ignition switch ON (ll), and set the radio presets and clock setting'
5'ToVerifytheprob|emisrepaired,test.drivetheVehic|eforseveralminutesatspeedsover30mph(48km/h).
14-51
Page 754 of 2189

Electrical Troubleshooting ('96 - 98 Models)
Troubleshooting Flowchart - E Indicator Light Does Not Gome On
PCM CONNECTOR A I32PI
Wire side of female terminals
Tha E indicator light does nolcome on when the ignition swhchis first turned ON (lll. {lt shouldcome on tol about two s€conds.l
Chock the SeJvico Check Connec-tor:Make sure the special tool (SCS
Seryice Conneclor) is not connect-ed to the service check connector.
ls the special tool (SCS ServiceConnector) connected to the service check connector?
Disconnect the special tool tromthc sarvice check connoctor androcheck.
Check th6 E indicator Light:Shift to lD.l oosition.
Check tor loose PCM connecto6.ll nece3sary, sub.titute a known-good FCM and r.chock.
Check the Ground Circuit:'1. Turn the ignition switch OFF.2. Disconnecr the A {32P}connec-tor lrom the PCM.3. Check for continuity betweenthe A9 terminal and bodyground and the A22 terminaland body ground.
Repair op6n in tho wirgsbetween tho A9 ot M2 tormi-nals and G101.Rcpair poor glound {G101).
To page 14-77
l.
14-76