2000 HONDA CIVIC heater control

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

Troubleshooting -'99 - 00 Models
Recirculation Control Motor (cont'd)
Frcm page 21-27
HEATER CONTROL PANEL 8P CONNECTOR
Check for a short to power in the
1. Turn the ignition switch ON {ll).2. Disconnect the heater controlpanel 8P connector.3. Check for voltage between theNo.2 and No. 3 terminals oftheheater control panel 8P con,nector and body ground individually.
Repair 3hort to powe. in thewire{a) b.tween tho haetor con-trol panel and the recirculationGontrol moto.. This short alsodamagos the heate. controlpanel. Repair the short to powerb€tore .eplecing the h€ater con-trol panel.
ls there any voltage?
Check to. a short to ground:1. Turn the ignition switch OFF.2- Check the same terminals forcontinuity to ground.
Roprir lhon in tho wir.{s) b€tweothe horter control panel and theracircr alion conhol motoa.
Check for an open in the wires:1. Disconnect the recirculationcontrol motor 4P connector.2. Check for continuity betweenthe following terminals of therecirculation control motor 4Pconnector and the heater con,trol panel 8P connector.8P: 4PiNo.2 - No.2No.3 - No.4
Repair open in ths wirolsl betw€€nthe heate. co.rkol panol and therecirculation control motor .
Check lor loo3a wires or pootconn€ctions at the hoater controlpanel 8P connector and at theaecirculation control motor ilPconnector, It tho connections aregood. substitut€ e known-goodheatei control panel, and aecheck.lf th€ symptom/indication goesaway, replace the original hedtercontrcl Danel.
GRN/WHT
I1
GRN/RED
RECIRCULATION CONTROL MOTOR4P CONNECTORWire side of female terminals
21-28

BIower Motor Speed
To page 21 30
NOTE: lf the blower motor does not
run at all, refer to page 21-31.
POWEB TRANSISTOR 3P CONNECTOR
BLK
Wire side ol female terminals
JUMPERWIRE
HEATER CONTROL PANEL 2OP CONNECTOR
Wire side of female terminals
LT GRN/8LK
(cont'd)
21-29
Blower motor only runs on high
speed position; it does not run in
any other speed Positions
Check for an open in lhe wire:
1. Disconnect the power transis
tor 3P connector,2. Check for continuity between
the No. 3 terminal of thepower transistor 3P connector
and body ground.
Check tor an open in the wire
between the Power ttansistor
and body gtound. lf the wire is
OK, check for poor ground at
G401 and G402.
ls there continuity?
Check tor an open in the wire:
1. Connect the No. 1 and No 3
terminals of the Power tran_
sistor 3P connector wlth ajumper wire.2. Turn the ignition switch ON {ll)
Repair open in the wire belweenthe blower motor and the Powettranststor.
Check tor an open in the wire:
1. Turn the ignition switch OFF
2. Disconnect the iumPer wire.
3. Disconnect the heater controlpanel 20P connector.4. Check for continuity between
the No. 1 terminal of the
heater control panel 20P con-
nector and the No. 2 terminal
of the Power transistor 3P
Repair open in the wire between
the heater control Panel and tho
oower transistor,ls there continurty)
3
o

Troubleshooting -'99 - 00 Models
Blower Motor Speed (cont'dl
HEATER CONTROL PANEL 2OP CONNECTOR
Wire side oJ female terminals
Wire side ot female terminals
Frcm page 21.29
LT GRN/BLK
Check tor a short in the wi.a:Check for continuity between theNo. 1 terminal of the heater control panel 20P connector and bodyground.
Repair short in ths wire betwsenthe hoater control panel and theoower transastoa.
Check for an open in the wire:1. Disconnect the heater controlpanel 8P connector,2. Turn the ignjtion switch ON 1ll).3. Measure the voltage betweenthe No. 'l terminal of theheater control panel 8P connector and body ground.
Repeir open in the wiio betweenthe heater control panel and theblower motoa.
Check the power transistor:1. Turn the ignition switch OFF.2. Reconnect the heater controlpanel 8P and 20P connectors.3. Test the power transistor {seepage 21 50).
ls the power transistor OK?
Check for loos€ wiras or poor con-nections at the h€at€r controlpanel 8P and 20P connectols andat th6 power transistor 3P conn€c-tor. lf the connections are good,substituto a known-good hoatercontrol panel, and recheck. It thesymptom/indication goes away,replace the original heater controloanel,
HEATER CONTNOL PANEL 8P CONNECTOR
21-30

Troubleshooting -'99 - 00 Models
Blower Motor {cont'dl
BLOWER MOTOR HIGH RELAY 4P CONNECTORWire side of female terminals
BLU/BLK
BLU/ALK
HEATER OONTROL PANEL 8P CONNECTORwir€ sido ot f€male torminals
HEATER CONTROL PANCL 2OP CONNECTORWire side of female terminals
From page 21-33
Check tor an opgn in the wiro:1. Disconnect the heater controlpanel 8P connector.2. Check lor continuity betweenthe No. 1 terminal of theheater control panel 8P con-nector and the No. 1 terminalot the blower motor highrelay 4P connector.
Repsi. op€n in the wir. betw.enthe h..t.r contrcl p.ncl .nd thoblowar motor high rahy.
Ch€ck for an opon in the wir6:1. Disconnect the heater controlpanel 20P connector.2. Check for continuity betweenthe No. 13 terminal of theheater control panel 20P con-nector and the No. 4 terminalof the blower motor highrelay 4P connector.
Ropair opon in tho wiro botwoontha hartor cor rol pangl rnd thablower motor high .elay.
Ch.ck for looso wiros or poor
conn€dions at th6 heato. controlpanel 8P and 20P connectoB andat the blowol motor high relty4P connoctor. It tho connoctionsare good, substitute a known-good heatcr control panel, andrecheck. It the symptom/indica-tion goos away, rgplaco the oiigi-nal heater control oanol.
2
34
o
t2
a568
I23a5078I10
11121315,/1,/1,/m
ORN/WHT
o
12
34
OBN/WHT
21-34

Both heater and A/C do nol work.
checkthe No.47 (7.5 A)fuse in the
under-hood fuse/relay box, and theNo. 17 {7.5 A) fuse in the under-
dash fuse/relay box.
ReDlace the tuse{s), and recheck.
Check lor an open in the wire:
1. Disconnect the heater controlpanel 8P connector,2. Turn the ignition switch ON (ll).
3. Measure the voltage between
the No. I terminal of the
heater control panel 8P con-
nector and body ground.
Repair open in the wire betweenthe No. '17 luse and th6 heatercontrol oanel,ls there battery voltage?
Check for an open in the wire:
1. Turn the ignition switch OFF.
2. Disconnect the heater controlpanel20P connector.3. Measure the voltage lletweenthe No. 10 terminal of theheater control Panel 20P con-nector and body ground.
Repair op6n in the wir€ between
the No. il7 tuse and the heater
controloanel,ls there battery voltage?
Check for an open in the wite:Check for continuity between theNo. 6 terminal of the heater con
trol panel 8P connector and bodyground.
Ch6ck tor an open in lhe wire
betwoen the heator control Paneland bodv ground. lf the wire isOK, check for poor ground atG401 and G402.
ls there continuity?
Check for looso wires or Poolconneciions at the heater controloanel 8P and 20P connectors. lf
the connections are good, substi'
tute a known-good heat€r con-trol Danel, and recheck. lI thesymptom/indication goes awaY,r6place the original h€ater con-troloanel.
HEATER CONTROL PANEL 8P CONNECTOR
BLK/YEL
Wire side of female terminals
HEATER CONTROL PANEL 2OP CONNECTOR
Wire side of temale terminals
I2
1578
BLK
o
1
4I
v