1999 HONDA CIVIC troubleshooting

Troubleshooting -'96 - 98 Models
Symptom Chart
NOTE;
. Check the engine coolant level. and allow the engine to warm up before troubleshooting.
. Any abnormality must be corrected before continuing the test.
. Because of the precise measurements needed. use a multimeter when testing.
o Before performing any troubleshooting procedures check:- Fuses No. 41 11.5 Al, No. 55 (40 A) in the under-hood fuse/relay box. and No. 17 (7.5 A) in the under-dash fuse/relay
box- Grounds No. G401, G402- Cleanliness and tightness of all connectors
SymptomRomedy
Hot air flow is low.Blower motor runs. but one or more
speeds are inoperative.
Perform the procedures in the flowchart (see page 21-8).
Blower runs properly.Check for the following:. Clogged heater duct. Clogged heater outlet. Incorrect door position
No hot air flow.Blower motor does not run at all,Perform the procedures in the flowchart (see page 21-10).
Blower motor runs.Check for the following:. Clogged heater duct. Clogged blower outlet. Clogged heater valve. Faultv air mix door. Heater valve cable adjustment (see page 21-44). Air mix control cable adiustment (see page 2'l-441. Faulty cooling system thermostat (see section 10). Clogged evaporator (with air conditioning). Frozen evaporator {with air conditioning)
Mode control motor does not run, or one or more modes
are inooerative.
Perform the procedures in the flowchart (see page 21-13).
Recirculation control door does not chanqe between
FRESH and RECIRCULATE.
Perform the procedu.es in the flowchan (see page 21-16).
Both heater and A,/C do not work.Perform the procedures in the flowchart (see page 21-18),
21-6

Troubleshooting -'96 - 98 Models
Blower Motor Speed
HEATER FAN SWITCH 6P CONNECTOR
Wire side of female terminals
21-a
Blower motor runs. but one orrnore speeds are inoperative,
Chsck for a short or an open inthe wire{s}:Turn the ignition switch ON {ll),and the heater fan switch OFF.
Does the blower motor run?
Check for a shon in th6 wirels):1. Turn the ignition switch OFF.2. Disconnect the blower motor2P connector,3. Remove the center dashboardlower cover (see section 20),and disconnect the heater lanswitch 6P connector,4. Disconnect the blower resistor 4P connector,5. Check for continuity betweenthe No. 2,3, 4 and 5lerminalsof the heater fan switch 6Pconnector and body ground
individually.
ls there continuity?Reolace the heater fan switch,
Repair short in the wire(s)beiween the blower resistor, theheater tan switch and the blowermotor,
To page 21 9

Troubleshooting -'96 - 98 Models
Blower Motor
BLOWER MOTOR 2P CONNECTOR
Wi.e side of fernale terminals
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Fl gr-urwnr
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I
glower motor does not run at all.
Check the No.55 (40A)luse in theunder hood fuse/relay box, andthe No. 17 (7.5 A) luse in theundeFdash luse/relay box.
Repl.ce th. fuse{rl, .nd rochack.
Check the blower motor:1. Connect the No. 2 terminal ofthe blower motor 2P connoctor to body ground with a
lumper wrre.2. Turn the ignition switch ON (ll).
Does the blower motor run?
Chock for an opsn in the wire:1. Disconnect the ,umper wireand the blower motor 2P con-nector,2. Measure the voltage betweenthe No. 1 terminal and bodyground.
ls there battery voltage?
Ch6ck tha blower motor relay:1. Turn the ignition switch OFF.2. Remove the blower motorrelay from the under-hoodfuse/relay box, and test it (see
page 21-49).
Replace tha blower moior reley.
To page 21-11
fo page21'12
21-10

Troubleshooting -'96 - 98 Models
From page 21-10
Check the under-hood fuse/relayDOX:N/leasure the voltage between theNo. 3 terminal of the blowermotor relay 4P socket and bodyground,
ls there baftery voltage?
Check lor an open in th€ wire:1. Turn the ignition switch ON (ll).
2. Measure the voltage betweenthe No. 4 terminal of the blow-er motor relay 4P socket andbody ground.
Repair open in tho wire betweenthe No. 17 fuss and tho blowelmotor rclay,
Check for en opon in the wire:1. Turn the ignition switch OFF.2. Check for continuity betweenthe No. 2 terminal of the blow-er motor relay 4P socket andbody ground.
Check foi an open in the wirebetwe€n the blower motor relavand body glound. lf the wiro isOK, check fo. poor ground atG{01 and G4O2.
ls there continuity?
Repair open in the BLU/WHTwire b€tween the blower motorrelav and the blower motor.
Blower Motor (cont'dl
BLOWER MOTOR RELAY 'P SOCKET
1211
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i
21-12

Troubleshooting -'96 - 98 Models
Mode Control Motor lcont'dl
From page 2l-13HEATER CONTROL PANEL lilP CONNECTOR
Wire side of lemaie terminals
Check tor a short in the wi.e(s):1. Remove the center dashboardlower cover (see section 20),and disconnect the heater con-trol panel 14P connector.2. Check for continuity betweenthe No. 1, 4, 7, 8 and 9 termi-nals and body ground individ-
Raprir.ny short in the wire(s)betw€en the mode control motorand the heater control panel.
Check for a shon to power:
Check the same wires {or voltage.
Repair short to pow6r in thewiro(3) betwoen the mode con-lrol motor .nd tha heate. controlprnel, This short also damag.stho heater cont.ol prnel. Repailthe short to power b€{ore replac-ing the heeter conlrol pan6l.
ls there any voltage?
To page 21 15
21-14

Troubleshooting -'96 - 98 Models
Recirculation Control Motor
Becirculation control door doesnot change between FRESH andRECIBCULATE.
check the No- 17 (7.5 A) fuse inthe under-dash fuse/relay box.
Reolace the tuse. and recheck.
Check for an open in the wire:1. 0isconnect the recirculationcontrol motor 4P connector.2. Tu.n the ignition switch ON (ll).
3. Measure the voltage betweenthe No. l terminal and bodyground.
Repair open in the wir6 betweenthe No. 17Iuse and the recircula-lion conlrol motor.ls there battery voltage?
Check lhe recirculation control
1. Turn the ignition switch OFF.2. Test the recirculation controlmotor {see page 21 48).
Check the recirculation controllinkage and door:1. Remove the recirculation con'trol motor {see page 21 48}.2. Check the recirculation controllinkage and door for smooth
Do the recirculation control linkage and door move smoothly?Reoair the r€circulation controllinkage or door.
RECIRCULATION CONTROL MOTOR4P CONNECTOR
BLK/YEI-
Wire side of temale terminals
Io page 21 17
21-16

Troubleshooting -'96 - 98 Models
Both heater and A/C do not work.
Check the No. 17 {7.5 A) fuse in theunderdash fuse/relay box, and theNo. 47 (7.5 A) fuse in the underhood fuse/relay box.
R.phce the fuso{s), .nd rccheck.
Chack tor an open in the wi.e:1. Remove the center dashboardlower cover (see section 20),and disconnect the heatercontrol panel 14P connector.2. Torn the ignition switch ON {ll).3. Measure the voltage betweenthe No. 2 terminal of theheater control panel 14P con-nector and body ground.
Rcpair opGn in th€ wiro betwoonthe No. 17 tuse and the hoatclcontrol panel.
ls there baftery voltage?
Check for an opon in the wiro:1. Turn the ignition switch OFF.2. Measure the voitage betweenthe No. 3 terminal of theheater control panel 14P con-nector and body ground.
Rgprii open in th6 wira b€twacnthe No. il7 tui. and the heat.tcont.ol p.nal.
ls there battery voltage?
Check foi an open in the wi.e:Check for continuity between theNo. 10 terminal ot the heater con-trol panel 14P connector andbody ground.
Check lor an opon in tho wireb€{w6on the hoator control oaneland body ground. lI the wirc isOK, check tor poor ground atG401 .nd G4O2.
Check for looae wiaos or ooolconnections at the hoater controlpanol 14P connector. lf the con-nactions dre good. 3ubstitute tknown-9ood heater controlpanel, and rech6ck. It tho symp-tom/indication 9oe3 .wry,replace the original heatel con-trol oanol.
Heater Control Panel
HEATER CONTROL PANEL 1,lP CONNECTOR
Wire side of female terminals
21-18

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