Page 1424 of 2189
Mode Control SwitchPower Transistor
Test -'96 - 98 Models
Check for continuity between the terminals accordinq tothe table below.
Terminal
Position't071
Heato-o
HeaVDefo---o
Defo--o
VentG-o
HeaVVento--o
1
;l t
4
789
21-50
Test -'99 - 00 Models
1. Disconnsct the 3P connector from the oower tran-stsror.
2, Carefully release the lock tab on the No. 2 terminal inthe 3P connector, then remove the terminal and insu-late it from body glound.
Connect a 1.2 - 3.4 W bulb between the No. 1 andthe No. 2 cavity on the 3P connector.
Reconnect the 3P connector to the power translstor.
Turn the ignition switch ON fll), and check that theblower motor runs.
12V 1.2-3,1W
No. 1 laLU/aLK)
Page 1435 of 2189
Check the diode:1. Disconnect the iumPer wire
2. Remove the A/C diode from
the under hood fuse/relaY box
3. Check for current flow in both
directions between the A and
B terminals.
ls there current flow in onlY
one direction?
Chock for an open in the wire:
1. Turn the ignition switch ON(ll).
2. Measure the voltage between
the No. 2 terminal of the AJC
diode 2P socket and body
ground.
Repair opon in the wire betwe€n
the No. 17 luse and the A/c
diode.ls there battery voltage?
B()-=iFA
A/C DIOOE 2P SOCKET
Page 1438 of 2189
![HONDA CIVIC 1999 6.G Workshop Manual Troubleshooting
Compressor lcontdl
COMPRESSOR CLUTCH RELAY4P SOCKET
l--;l
12 |---r--]l.l3 |L-J--J
] BLK/YEL
A(v)
!
ECM/PCM CONNECTOR A I32P}
Wire side of female terminats
*Howto use the backprobe set HONDA CIVIC 1999 6.G Workshop Manual Troubleshooting
Compressor lcontdl
COMPRESSOR CLUTCH RELAY4P SOCKET
l--;l
12 |---r--]l.l3 |L-J--J
] BLK/YEL
A(v)
!
ECM/PCM CONNECTOR A I32P}
Wire side of female terminats
*Howto use the backprobe set](/manual-img/13/6068/w960_6068-1437.png)
Troubleshooting
Compressor lcont'dl
COMPRESSOR CLUTCH RELAY4P SOCKET
l--;l
12 |---r--]l.l3 |L-J--J
] BLK/YEL
A(v)
!
ECM/PCM CONNECTOR A I32P}
Wire side of female terminats
*Howto use the backprobe setsConnect the backprobe adapters to the stackang patch cords, andconnect the cords to a multimeter. Using the wire insulation as aguide for the contoured tip of the backprobe adapter, gently slidethe tip into the connector from the wire side until it comes in con-tact with the terminalend ofthe wire (see section 11).
Frcm page 22-12
To page 22-15
Check Ior an open in the wire;1. Disconnecl the jumper wire.2. Turn the ignition swatch ON (ll).
3. l\4easure the voltage betweenthe No. 4 terminal of the com-pressor clutch relay 4P socketand body ground.
Repair open in the wire betw€enthe No. 17 fuso and the compres-sor clutch relav.
Check for an open in the wira:1. Turn the ignition switch OFF,then reinstall the compressorclutch relay.2. Make sure the A/C switch isOFF, then turn the ignitionswitch ON (ll).
3. Using a *Backprobe Set (T/N07SAZ 0010004), measurethe voltage between the No.17 terminal oI the ECM/PCMconnector A (32P) and bodyground with the ECM/PCMconnectors connected.
Repair open in the wirc betweonthe compressor clutch relay andthe ECM/PCtvt.
ls there battery voltage?
Page 1439 of 2189
Frcm page 22-14
Check lor an open in the wire:1. Turn the ignition switch OFF.
2. Disconnect the A/C pressure
switch 2P connector.3. Turn th ignition switch ON lll).4. Measure the voltage between
the No. 1 terminal of the AJCpressure switch 2P conneclorand body ground.
Check the A/C pressure switch:1. Turn the ignition switch OFF.
2. Check for continuity between
the No. 1 and No. 2 terminalsof the Ay'C pressure switch.
ls there continuity?
Check for A/C system ptessure.
ls the pressure within sPeci_f cations?Repair the A/C pressure Problem
A/C PRESSURE SWITCH 2P CONNECTOR
ls there battery voltage?
wire side of {emale terminals
A/C PRESSURE SWITCH
Repair open in the wire between
the condenser fan relay tnd the
A/C oressure switch.
1o page 22-16
(cont'd)
22-15
Page 1440 of 2189

Troubleshooting
Gompressor (cont'dl
'96 -98 models:
ECM/PCM CONNECTOR C 13lPI
Wire side ot female terminals
'9!t - 00 mod.bi
ECM/PCM CONNECTOR A I32P)
Wire side ot female terminals
*How to use the backprobe setsConnect the backprobe adapters to the stacking patch cords, andconnect the cords to a multimeter. Using the wire insulation as aguide for the contoured tip of the backprobe adapter, gently slidethe tip into the connector from the wire side until it comes in con-tact with the terminal end ofthe wire {see section 11}.
From page 22-15
Check for an open in thg wire:'1. Reconnect the A"/C pressure
switch 2P connector.2. Make sure the A/C switch isOFF, then turn the ignitionswitch ON (ll).
3. Using a *Backprobe Set {T/N07SAZ - 001000A), measurethe voltage between the No. 5terminal of the ECM/PCM con-nector C (31P) and bodyground with the EcM/PcMconnectors connected ('96 -
98 models), or between theNo. 27 terminal of theECM/PCM connector A (32P)
and body ground with theECM/PCM connectors connected ('99 - 00 models).
Rapdir open in tho wi?e botwaonthe A/C pr..-ruro lwitch rnd th.ECM/PCM.
Check lor loo3e wires or ooolconnections at the ECM/PCMconnectoB A l32P) and at the A/Cpressure switch 2P connector, lfthe connections are good, substi-tute a known-good ECM/PCM,and recheck. lf the svmptom/indication goos away, repbce theoriginal ECM/PCM.
31501E91011
tat6l11E1921222321
BLU/RED
22-16
Page 1441 of 2189
A/C System
CONDENSER FAN RELAY 4P SOCKET
A/C system does not come on
{comDressor and fan).
Check the No. 56 fuse in theunder'hood fuse/relay box andthe No. 17 fuse in the under-dashfuse/relay box.
ReDlace the fus6{s}, and recheck.
Check for tn open in the wire:
1. Remove the condenser lanrelay from the u nderhood
luse/relay box.2. Turn the ignition switch ON {lli.3- Measure the voltage betweenthe No. 4 terminal of the condenser fan relav 4P socketand body ground.
Repair open in the wire between
the No. 17 fuse and the con-denser fan r6lay,
Check the under-hood fus€/r6laybox:Measure the voltage between the
No. 2 terminal of the condenser
fan relay 4P socket and bodyground,
YES
Io page 22-18
(cont'd)
Page 1442 of 2189

Troubleshooting
A/C System (cont'd)
From page 22-11
. _Ff,, __
I11213[
,r,il*"-T",-.r-'..owrRE I
To page 22-19 1'96 - 98 models)
A/C THERMOSTAT 3P CONNECTOR
Wire side oI female terminals
Check tor an open in the wire:1. Turn the ignition switch OFF.2. Disconnect the A/C thermostat 3P connector.3. Turn the ignition switch ON (ll).
4. Measure the voltage betweenthe No. 3 terminal of the Ay'Cthermostat 3P connector andbody ground.
Repai. open in the wire betweentho No. 17 tuso and the A/C the.-mostat.
Check loi an open in the wi.e:Measure the voltage between theNo. 1 terminal of the A,/C thermostat 3P connector and bodyground,
Ropair open in the wire betwoenthe condedlo. lan rolay and theA/C thormostat.
ls there battery voltage?
Check the A/C th6rmostat:1. Turn the ignition switch OFF.2. Reconnect the A,/C thermostat3P connector.3. Connect the No. 2 terminal toground with a iumperwire.4. Start the engine.
Do the fan run and the com-pressor clutch engage?
To page 22-20 ('99 - 00 models)
22-18
Page 1443 of 2189

Ftom page 22 18
Check tor an open in the wire:1. Turn the ignition switch OFF,then disconnect the iu mper
2. Remove the center dashboardlower cover lsee section 20),
and disconnect the heater con'
trol panel 14P connector.
3. Turn the ignition switch ON (ll).
4. Measure the voltage betweenthe No. 11 terminal and bodyground.
Repair op6n in the wire bstween
the A/C th€rmostat and th6 hoater
control panel.
Check lor an open in the wire:
1. Turn the ignition switch OFF.2. Disconnect the heater Ian
switch 6P connector,3. Check for continuity between
the No. 14 terminal of theheater control panel 14P con_nector and the No.6 terminalof the heater fan switch 6P con-nector.
Repair open in the wiro betweGnthe heal.r control Panel and theheater fan switch.
Check for an open in thG wire:Check for continuity between theNo. 1 terminal of the heater lanswatch 6P connector and bodYground.
Chock tor an open in tho wir€
between the heater lan switch
and body ground. lf the wire is OK,check for poor ground at G401 sndG402.
ls there continu;ty?
ReDlace the heater tan switch.ls the heater fan switch OK?
Check for loose wiaes or poor
connections at the heater controloanel 14P connoctor and hoetertan 3witch 5P conn€clor and atthe A/C thermostet 3P connec-tor. ll the connections are good,
raplace the heator control Panel.
r'oA - qe m^.lalal
HEATER CONTROL PANEL lilP CONNECTOR
tra6
7II'o lx't1121314
BLU/RED
Wire side of female terminals
HEATER CONTROL PANEL 1'P CONNECTOR
Wire side of female terrninals
HEATER FAN SW]TCH 6P CONNECTOR
Wire side of female terminals
(cont'd)
12;--?45
7I10X'll121314
GRN
123
a56GRN
22-19