1999 HONDA CIVIC ect

Troubleshooting -'99 - 00 Models
Symptom
Mode control motor does not run, or one or more modes are inoperat've'
Recirculation control door does not change between Fresh and Recirculate'
Blower motor only runs on high speed position; it does not run in any other speed positions
Blower motor does not run at all.
Both heater and Ay'C do not work
See pags
a1_tq
21-21
21-29
21-31
21 35
Symptom Chart
For electrical malfunctions which are indicated by the self-diagnostic system, refer to self-diagnosis function (see next
page).
Note these items before troubleshooting a symptom'
. Check the engine coolant level, and allow the engine to warm up before troubleshooting'
. Any abnormality must be corrected before continuing the test
.Becauseoftheprec|semeasurementsneeded,UseadigitaImu|timeterwithanoutputoflmAor|essatthe20ko
range when testing
. Before performing any troubleshooting procedures check:
- Fuses No. 41 115 Al, No 55 (40 A)]n the under-hood fuse/relay box' and No 17 (7 5 A) in the under-dash fuse/relav
box- Grounds No. G401, G402
- Cleanliness and tightness of all connectors
21-19

Air Mix Gontrol Motor
Recirculation indicator light indicates Diagnostic Trouble code (DTC) 1l A problem in the air mix control linkage, door and
motor.
The air mix control motor regulates the mixture of cool/hot air according to outputs from the heater control panel'
Self-diagnosis circuit check indi'
cates a Problem in the air mix
conlrol motor circuit,
Check th6 aii mix conirol 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 lor smooth
movement.
ls the air mix control motor OK?
Do the air mix control linkage and
doors move smoolhlY?
R€olace the air mix control motor'
Check tor a short in the wiles:
1. Disconnect the heater controlpanel 20P connector-2. Check for continuitY between
body ground and the heater
control panel 20P connector
terminals No.3 and 4 individ'
uaIY.
Ropair any short in th€ wire{s}
betweon the heater control Paneland the air mix control motor'
HEATER CONTROL PANEL 2OP CONNECTOR
RED/WHTRED/YEL
Wire side ot female terminals
(cont'd)
fo page 21-22
21-21

Troubleshooting -'gg - 00 Models
Air Mix Control Motor (cont'dl
Frcm page21-21
AIR MIX CONTROL MOTOR5P CONNECTORWire side ot female terminals
Check fo..n open in the wires:Check for continuity between lol-lowing terminals of the heatercontrol panel 20P connector andthe air mix control motor 5P con-
20P: 5P:No3 _ No. 1No.4 - No.5
Repair any open in the wiro(s)bdtwoon tha hoator control panaland air mix control motor.
Check for loo3e wires or poorconneclions at the heater controlpanol 20P connoctor and at theair mix control motor 5P connoc-to.. It the connections .rc good,substitute a known-good hoaiercontrol panel, and rech6ck. lf thesymptom/indicrtion goes away,replac6 the original heater con-trol panel.
21-22

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

Troubleshooting -'99 - 00 Models
Check tor a short to power:
Check the same terminals forvoltage.
Rapair short to pow6r in thewirelsl botween the heater con-trol panel and the ai. mix controlmolor. This short also damag.sthe heater control panel. Ropairthe short to power betoro replac-ing the heater control panel.
ls there any voltage?
Check for an open in the wire3:Check for continuity between following terminals of the heatercontrol panel 20P connector andthe air max control motor 5P connector.20Pt 5P:No3 _ No. 1No 4 _ No. 5No_ 12 - No. 2No. 15 - No.4No 20 - No.3
Bepair any open in the wire(s)between the heator control paneland air mix control motor,
Check tor loose wires or poorconnections at the heator controloanel 20P connector and at th.air mix control motor 5P connec-tor, ll the connections rre good,substitute a known-good heatercontrol oanel. and recheck. lf thesymptom/indication goes awry,replace the original heater con-trol oanel,
Air Mix Control Motor (cont'dl
From page 21-23HEATER CONTROL PANEL 2OP CONNECTOR
AIR MIX CONTROL MOTOR5P CONNECTORWire side of lemale terminals
Wire side of female terminals
21-24

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

Troubleshooting -'gg - 00 Models
Mode Gontrol Motor (cont'dl
From page 21-25
MODE CONTROL MOTOR ?P CONNECTORWire sade of lemale terminals
Chock tor a short to ground:1. Turn the ignition switch OFF.2. Check the same terminals forcontinuity to body ground.
Repair any 3hort in the wirelslbetween the heater control paneland ihe mode control motor.
ls there continuity?
Check lor.n open in tho wires:1, Disconnect the mode controlmotor 7P connector.2. Check for continuity betweenthe following terminals of theheater control panel 20P connector and the mode controlmotor 7P connector.2OP: lPiNo.2 - No.7No.5- No.2No.6- No.6No.7 - No.5No.8- No.4No.I - No.3
Repair any opon in the wire(s)t€tween the h€ater control paneland tha modc contol motor.
ls there continuity?
Check for loose wiaes or ooorconnections at the heater controlpanel 20P connector rnd at themode control motor 7P connec-toa, lf the connoctions ere good,substitute a known-good heatercontrol panol, and recheck. lf thesyfiptom/indication goes away,replac€ the original hoater controlpanel.
HEATER CONTROL PANEL 2OP CONNECTOR
Wire side of female terminals
21-26

Recirculation control door does
not chango betwe€n Fresh and
Recirculate.
Check the No. l7 (7.5 A) fuse an the
underdash fuse/relay box.
Replace the fuse, and recheck.
Check lor an oPen in the wite:
1. Disconnect the recirculation
control motor 4P connector.
2. Turn the ignition switch ON (ll)
3. Measure the voltage between
the No. 1 terminal of the recir
culation control motor 4P
connector and body ground.
Repair open in the wire between
the No. 17 luse and lhe recircula-
tion control motor.ls there battery voltage?
Check the rccirculation control
motorr'] Turn the ignition switch OFF.
2. Test the recirculation control
motor (see Page 21 48i
Check the recirculation control
linkage and door:1. Remove the recirculation con_
trol motor lsee Page 2l 48).
2. Check the recirculation control
linkage and door for smooth
movement.
Reoair the recirculation conlrol
linkag€ or door.Do the recirculation control link_
age and door move smoothlY?
CONTROL MOTOR
side of temale terminals
RECIRCULATION CONTRC,lP CONNECTOR
q-?--T--T--T-|1l2l/l1l
f BLK/YEt(v)
!
page
(cont'd)