
PGM-FI System
Throttle Position ITP) Sensor ('96 - 98 Models,'99 - 00 D16Y5 engine with M/Tl
The scan tool indicates Diagnostic Trouble Code (DTC) P0122: A low voltage problem in the Throttle Position(TP) sensor circuit.
The TP Sensor is a potentiometer. lt is connected to the throttle valve shaft. As the throttle position changes, the throttleposition sensor varies the voltage signal to the ECM/PCM.
OUTPUT VOLTAGE IVI
1
2
1
0
s{i2(GRN/BLKI
THROTTLEOPENING
FULLTHROTTLE
TP SENSOR 3P CONNECTOR ICllOI
vocz(YEL/BLUI
Wire side ot femal6 terminals
ECM/PCM CONNECTOR D IT6PI
SG2 IGRN/ALKI
{To page l1-133)
Terminal side of male terminals
11-132
- Tho MIL h63 boon roportod on.- DTC m122 i. storcd.
Probl6m voritic€tion:1. Turn the ignition switch ON (ll).
2. Check the throttle positionwith the scan tool.
ls there approx. .49 V whenthe throttle is fully closed andapprox. 4.5 V when the throttleis lully op6ned?
Int..mittent tailura, rFiem ir OKat thit tima. Chock tor Door con-nections or loorc wires !t C110ITP lonrorl .nd ECM/FCM.
Ch6ck lor rn opon in the wire(VCC2linel:
1. Turn the ignition switch OFF.2. Disconnect ths TP sensor 3Pconnector.3. Turn the ignition switch ON lll).4, Measure voltage betweenthe TP sensor 3P conn€ctor ter-minals No. l and No.3.
ls there approx. 5 V?
Check for rn opcn in wire IVCC2line):Measure voltage between ECM/PCM conneclor terminals D10 and011.Chock for rn open or 3hort in TPlon30t:1. Turn the ignition switch OFF.2. At the s€nsor side, measureresistance between the TP sen-sor terminals No. 1 and No. 2with the throttle fully closed.
Roplir op€n in thg wiro batwcsnECM/PCM {DlO) rnd TP ren3or.ls there approx.5 V?
Substitut6 r known-good ECM/PCM and rach6ck. lf pro$ribodvohrge i! now avrilablc, replac€tho o.iginel €CM/FCM.
Wire side of female terminals

PGM-FI System
l:in1.".fy Heated Oxygen Sensor (primary HO2SI (sensor 1l(D16Y5 engine with M/D (cont'd)
The scan toor indicates Diagnosti" -Tl:y|* code (DTC) pl164: A range/performance probrem in the primaryHeated Oxygen Sensor (primary HO2S) (Sensor 1)circuit.
The scan tool indicates Diagnostic Trouble Code (DTC) p1165: AHeated Oxygen Sensor (primary HO2S) (sensor 1) circuit.
range/performance problem the pnmarv
The MIL has beon reponed on.DTC P1164 is stored.
Problem Verilication:1. Do the ECM Beset Procedure.2. Start the engine. Hold theengine at 3,000 rpm with noload (transmission in neutral)untilthe radiatorfan comes on.3. Connect the SCS service con-nector.4. Test-drive in 4th gear. Startingat 1,600 rpm, accelerate usingwide open throttle for at least 5seconds. Then decelerate tor atleast 5 seconds with the throttle completely closed.
Intgrmittent failure, syrtem b OKat this time. Check tor Door con-noctions or loose wires at C1a5(Primary HO2S. Senso.
andECM.
ls DTC Pl164 indicatedT
- The MIL has been reoorted on.- DTC P1165 is stored.
Intermittent l.iluro, system b OKat lhis time. Ch€ck tor poor con-noctions or loose wir6 at Ci45(Prioary HO2S, Sen3or 1l .ndECM.
ls DTC P1165 indicated?
Replace the P.imary HO2S (S6n-sor 11.
Problem Vo.ification:1. Do the ECM Reset Procedlre.2. Start the engine. Hotd theengine at 3,000 rpm with noload (transmission in neutral)until the radiator fan comes
3. Connect the SCS service con,nector.4. Test-drive u nder followingconditions.- 55 mph steady speedTransmission in 5th gearUntil readiness code comes
1 1-150

PGM-FI System
Vehicle Speed Sensor (VSSI ('96 - 98 Models,'99 - 00 D16Y5 engine with M/Tl
@The scan tool indicates Diagnostic Trouble Code (DTC) P0500: A malfunction problem in the Vehicle SpeedSensor (VSS) circuit Iexcept A!/T (D16Y7, D16Y8 engine)1.
The scan tool indicates Diagnostic Trouble Code (DTC) P0501: A range/performance problem in the VehicleSpeed Sensor (VSS) circuit [A,rT {D16Y7, D16Y8 engine)].
ECM/PCM CONNECTORS
A {32P} LG.t
VSS IBLU/WHT}
Wire side ot temale terminals
LGI(BRN/8LK}
The MIL has been reDorted on.DTC P0500 or P0501 is stored.
Problem verification:1- Test drive the vehicle.2. Check the vehicle speed withthe scan tool.
Intermittent tailure, system is OKat this time. Check tor Door con-nections or loose wires at C117{VSSland ECM/PCM.
ls the correct speed indicated?
Check for an open in the ECM/PCM:1. Turn the ignition switch OFF.2. Elock the rear wheels and setthe parking brake.3. Jack up the front of the vehicleand support it with safetystands.4. Turn the ignition switch ON (ll).
5. Block the right tront wheel andslowly rotate the left front
6, Measure voltage between theECM/PCM connector termi-nals C18 and A9.
Subslitute a known-good ECM/PCM and recheck. lf symptom/indic.tion goes away, replace theorisinal ECM/PCM.
Does the voltage pulse 0 Vand 5 V?
Check tor a short in ihe ECM/PCM:1. Turn the ignition switch OFF.2. Disco n n ect the ECM/PCMconnector C (31P).
3. Turn the ignition switch ON {ll).4. Block the right front wheeland slowly rotate the left front
5. Measure voltage between theECM/PCM connector terminalsC18 and A9.
Substitute a known-good ECM/PCM and recheck. lI symptom/indication goes away. replacethe original ECM/PCM.
Does the voltage pulse 0 Vand s V?
- Repair short in the wirebetwGen ECM/PCM {C18} endvss, TcM.- Repair open in the wirebetween ECM/PCM {Cl8} andvss.- lf wire is OK, test the VSSlsee section 23).
{BRN/BLK}
239l0lt
121611t8t9202321
2A2930
c {31P}
I38191o
tl12ialr5i6l10./
I2356a9l011
12l3l5t61tl8t920222a
27202930
12910
t2l13l.l7I l,/ 1,/231r.lslt., ),rlL
VSS {BLU/WHT}
11-176

PGM-FI System
Elestrical Load Detector (ELDI ('99 - 00 Models except D16y5 engine with M/Tl
The scan tool indicates Diagnostic Trouble code (DTCI Pl298: A high vottage problem in the Etectrical LoadDetector (ELD) circuit.
ELD 3P CONNECTOR (65/0
EL {GRN/REOI
Wire side of fernale terminals
ELD 3P CONNECTOR (CA54I
TIr l2l3l
I crvo
(o) (BrKr
Y
Wire side of lemale terminals
ECM/PCM CONNECTORSA (32P1
Wire side of lemaleEI- IGRN/RED)terminals
ECM/PCM CONNECTORS
A {32P)
Problem ve.itication:1. Do the ECN4/PCM Reset pro
cedure.2. Start the engine.3- Turn on headiights.Inte.mittent teilu.e, svstem is OKat this lime. Chock for Door con-nections or loose wires at Ci31{located under Jight side otdaihl, C354 (ELD) and ECM/PCM.
ls DTC P1298 indicated?
Check for an open in the wire{lG1 line}:1. Turn the ignition and head-lights OFF.2. Disconnect the ELD 3P con
3. Turn the ignition switch ON (ll).4. Measure voltage between bodyground and the ELD 3P connec-torterminalNo. 1.
Repair opon in tho wiro batwe€nNo. 15 ALTERNATOR Sp SENSOR{7.5 A} fuse in th6 undor-dashIuse/reley box and ELD.
ls there battery voltage?
Check for an open in the wiro{GND linel:1. Turn the ignition switch andheadlights OFF.2. Disconnect the ELD 3P connector.3. Check for continuity betweenbody ground and the ELD 3Pconnector terminal No. 2,
Repair open in the wire bstwoenELD connsctor and Gia02.
Check ,or an open in the wire IELlinel:1. Disconnect the ECM/PCM con-nector A (32P).2. Check for continuity betweenthe ELD 3P connector terminalNo. 3 and ECM/PCM connec-tor terminal A30.
Chock fo. a malfunction in the ELD:'1. Reconnect the ELD connectorand ECM/PCM connectorA (32P).
2. Stan the engine and allow itto idle.3. While measuring voltagebetween ECM/PCM connectorterminals A30 and B2O, turnthe headlighrs on ow).
ls there continuity?
Repsir op€n in the wire betweenELD connector and ECM/PCM.
Substitute a known-good ECM/PCM and recheck. lf symptom/indication goes away. replacelh6 original ECM/PCM.
Does the vokage drop?
Wire side of f€male terminals
11-182

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

RecirculationindicatorIightindicatesDiagnosticTroublecode(DTc)2:AprobIemintheairmixcontro|motorcircuit.
The air mix control motor regutates the mi)dure of cool/hot air according to outputs from the heater control panel'
Self-diagnosis circuit check indi-
crl6s a problgm in tho air mix
contiol motor circuit.
Check th6 rir mix control motor:
1. Disconnect the air mix control
motor 5P connector'
2. Test the air mix control motor(see page 21-46).
Check the air mix control linkage
and doors:1. Remove the air mix control
motor (see page 21'46).
2. Check the air mix control link-
age and doors for smooth
ls the air mix control motor OK?
Do the air mix control linkage and
doors move smoothlY?
Roglace the air mix conlrol motor.
Check for r short in the wiresl
1. Disconnect the heater controlpanel 20P connector.2. Check for continuity between
body ground and the heater
control panel 20P connector
terminafs No. 3,4. 12,15 a^d
20 individually
Bep.ir any short in the wire{s)
between the h€rter control panel
and th6 air mix control motor.ls there continuity?
HEATER CONTROL PANEL 2OP CONNECTOR
BEO/WHTREO/YEL
PNK/BLK
Wire side of female terminals
(cont'd)
Io page 21-24
21-23
![HONDA CIVIC 1999 6.G Workshop Manual Mode control motor does not run.
or one or more modes arc inope]a-
tive.
Check the No. 17 (7.5 A) fuse in
the under-dash fuse/relay box.
Replace the Iuse. and recheck.
Check for an open in the wire:
1 HONDA CIVIC 1999 6.G Workshop Manual Mode control motor does not run.
or one or more modes arc inope]a-
tive.
Check the No. 17 (7.5 A) fuse in
the under-dash fuse/relay box.
Replace the Iuse. and recheck.
Check for an open in the wire:
1](/manual-img/13/6068/w960_6068-1398.png)
Mode control motor does not run.
or one or more modes arc inope]a-
tive.
Check the No. 17 (7.5 A) fuse in
the under-dash fuse/relay box.
Replace the Iuse. and recheck.
Check for an open in the wire:
1. Disconnect the mode control
motor 7P connector,
2. Turn the ignition switch ON (ll)-
3. MeasLrre the voltage between
the No. 1 terminal of themode control motor 7P con
nector and body ground
Repair open in the wire between
the No. 17 luse and lhe mode
control motor.ls there battery voltage?
Check the mode control motor:
1- Turn the ignition switch OFF
2, Test the mode control motor(see page 21 47).Check lhe mode control linkage
and doors:1. Remove the mode controlmotor (see page 21 47).
2. Check the mode control linkage
and doors for smooth move
ls the mode control motor OK?
Do the mode control linkage
and doors move smoothlY?
ReDlace the mode control motor'
Check for a short to Power in the
wires:1. Iurn the,gnitjon switch ON(ll).
2, Disconnect the heater controlpanel20P connector.3. Check for voltage betweenthe No. 2, 5, 6, 7, I and 9 ter'minals of the heater controlpanel 20P connector andbody ground individuallY.Repair shorl to power in the
wire{sl between the heater con-
trol oanel and the mode controlmotor. This short also damagesthe heater control Pan6l. RePair
the short to power before replac'ing the heater control Panel
ls lhere any voltage?
MODE CONTROL MOTOR 7P CONNECTOR
t2315
BLK/YEL
Wire side of female terminals
HEATER CONIROL PANEL 2OP CONNECTOR
Wire side of female terminals
NO
(cont'd)
21-25Io page 21 26

Function Test
CAUTION: Be careful not to damage the mirror switch
or the dashboard drivel's lower covel when prying the
swhch out.
Withoui defogger:
1. Pry the switch out of the driver's dashboard lower
cover.
2. Disconnect the 10P connector from the switch.
lOP CONNECTOR
BLU/WHT
YEL/RED
BLK/YELBLK
4
568
YEL/BLK
POWER MIRRORswtTcH
\:/"*jgil*-(
Wire side of female termanals
Mirror Test
Both inoperative:
1. check for voltage between the No. 2 (BLVYEL) ter
minal and body ground with the ignition switch ON
0 r).
There should be batterY voltage
. If there is no voltage, check for:
- blown No. 17 (7 5 A) fuse in the under-dash
tuse/relay box- an open in the BLK'/YEL wire.
o lf there is battery voltage, go to step 2.
2. Check for continuity between the No 4 (BLK) termi-
nal and body ground.
There should be continuity.
. lf there is no continuity, check for:
- an open in the BLK wire.
- poor ground (G551).
Left mirror inoporalive:
connect the No. 2 {BLK/YEL) terminal of the 10P connec-
tor to the No. 3 (YEURED) terminal and the No 5 (or No
6) terminal to body ground with jumper wires The left
mirror should tilt down (or swing left) when the ignition
switch is turned ON (ll)
. lf the mirror does not tilt down (or does not swing left),
remove the left door panel. and check for an open in
the BLU/WHT (or BLU/BLK) wire between the left
power mirror and the switch
- lf the wire is OK. check the left power mirror actua-
tor.
lf the mirror neither tilts down nor swings left. repair
the YEURED wire.
lf the mirror operates properly, check the mirror switch'
Right mirror inoperative:
Connect the No. 2 (BLK /EL) terminal of the 10P connector
to the No. 3 (YEURED) terminal and the No. 9 (or No 8)
terminal to body ground with jumper wires The right mir-
ror should tilt down (or swing left) when the ignition
switch is turned ON (ll).
. lf the mirror does not tilt down (or does not swlng
left), remove the right door panel. and check for an
open in the GRN/WHT (or YEUBLK) wire between the
right power mirror and the switch.
- lf the wire is OK, check the right power marror actu-
ator.
. lf the mirror neither tilts down nor swings left. repair
the YEURED wire
. lf the mirror operates properly, check the mirror
switch.
(cont'd)
23-209