Heating and Air Conditioning
DTC Troubleshooting
DTC 7: An Open in the Air Mix Control Motor
Circuit
1. Test the air mix control motor {see page 2'l-341.
ls the air mix control motor OK?
YES-Go to step 2.
NO-Replace the air mix control motor.l
2. Disconnect the air mix control motor 5P connector.
3. Disconnect heater control panel connectors A {14P)
and B (22P).
4. Check for continuity between the following
terminals of heater control panel connectors A
(14P) and B (22P) and the air mix control motor 5P
connector,
14P: 5P:
No. 1 No.5
No.2 No.4
No.3 No.2
No.9 No. 1
22P: 5P:
No.6 No.3
Wire side ol lem.letehi.6ls
ls there continuity?
YES-Check for loose wires or poor connections at
heater control oanel connectors A (14P) and B (22P)
and at the air mix control motor 5P connector. lf the
connections are good. substitute a known-good air
mix control motor, and recheck, lf the symptom/
indication goes away, replace the original air mix
control motor. lf the symptom/indication continues,
substitute a known-good heater control panel, and
recheck. lf the symptom/indication goes away,
replace the original heater control panel.l
NO Repair any open inthewire(s) ketweenthe
heater control panel and the air mix control
motor.l
21-16
DTC 8: A Short in the Air Mix Control Motor
Circuit
1. Test the air mix control motor(see page 21-341.
ls the ait mix control motor OK?
YES-Go to step 2.
NO-Replace the air mix contorol motor.I
2. Disconnect the air mix control motor 5P connector.
3. Disconnect heater control panel connectors A (14P)
and B (22P).
4. Check for continuity between body ground and
heater control panel connector A (14P) terminals
No. 1, 2, 3, and 9 individually, and between body
ground and heater control panel connector B (22P)
terminal No. 6.
HEATERCONTROL PANEL CONNECTOR A {I4PI
HEATER CONTFOL PANELCONNECTOR B I22P1
ls therc continuity?
YES-Repair any shortto body ground ln the
wire(s) between the heater control panel and the air
mix control motor.l
NO-Go to step 5.
Wire side of female terminals
Wire side oilema e lerminals
Heating and Air Conditioning
Compressor Clutch Circuit
Troubleshooting (cont'dl
16. Check for continuity between the No. lterminal of
the compressor clutch relav 4P socket and the No. l
terminal of the compressor clutch 1P conneclor.
COMPRESSON CLUTCH RELAY 4P SOCKET
COMPRESSOR CLUTCH 1P CONNECTORTerminal side of male terminals
ls therc continuity?
YES-Check the compressor clutch clearance, the
thermal protector, and the compressor clutch field
coil (see page 21-48).I
NO-Repair open in the wire between the
compressor clutch relay and the compressor
clutch.l
21-32
A/C Pressure Switch Circuit
Troubleshooting
'1. Turn the ignition switch ON {ll).
2. Turn the blower switch on, and check for blower
motor operatron.
Does the blower motor run on all speeds?
YES Go to step 3.
NO Troubleshoot the blower motor circuit (see
page 21-20).
3. Turn the ignition switch OFF.
4. Disconnect heater control panel connectorA ('14P).
5. Turn the ignition switch ON (ll).
6. Measure the voltage between the No, 4 terminal of
heater control panel connector A {14P) and body
grou nd.
HEATER CONTROL PANEL CONNECTOR A (I4P}
1.
ls there battety voltage?
YES Go to step 7.
NO-Go to step 9.
Stan the engine.
Wire side of female termina's
Compressor Replacement
1. lf the compressor is marginally operable, run the
engine at idle speed, and let the air conditioning
work for a few minutes, then shut the engine off.
2. Make sure you have the anti-theft code for the radio,
then write down the frequencies for the radio's
preset buttons.
3. Disconnect the negative cable from the battery.
4. Recover the refrigerant with a recovery/recycling/
charging station (see page 21-53).
5. Remove the alternator (see page 4-29).
6. Remove the Ay'C condenser fan assembly (see page
10-10).
7. Disconnectthe compressor clutch connector (A),
remove the bolts, then disconnect the suction line(B) and the discharge line (C)from the compressor.
Plug or cap the lines immediately after
disconnecting them to avoid moisture and dust
contamination.
6 x '1.0 mm9.8 N.m11.0 kgt.m,7.2 tbl.ttl
u1/
(
o
8. Remove the mounting bolts and the compressor.
8 x 1.25 mm22 N.m 12.2 kgf.m.
9. Installthe compressor in the reverse order of
removal, and note these items:
. Before installing the new compressor, check for
metal or other contamination in the line. Replace
any contaminated parts.. lf you're installing a newcompressor, you must
calculate the amount of refrigerant oil to be
removed from it (see page 21-6).. Replace the O-rings with new ones at each fitting,
and apply a thin coat of refrigerant oil before
installing them. Be sure to use the correct O-rings
for HFC-134a {R-134a) to avoid leakage,. Use refrigerant oil (KElHlN SP-'10) for HFC-134a
KEIHIN spiral type compressor only.. To avoid contaminatlon, do not return the oilto
the container once dispensed, and never mix it
with other refrigerant oils.. lmmediately after using the oil, reinstallthe cap
on the container, and seal it to avoid moisture
absorption.. Do not spill the refrigerant oil on the vehicle; it
may damage the paint. lf the refrlgerant oil
contacts the paint, wash it off immediately.. Charge the system (see page 21-55).. Do the engine control module (ECM) idle learn
procedure (see page 11-'139).. Enter the antitheft code for the radio, then enter
the customer's radio station presets.
21-47
Heating and Air Gonditioning
1.
Compressor Clutch Check
Check the armature plate for discoloration, peeling,
or other damage. lf there is damage, replace the
clutch set (see page 21-49),
Check the rotor pulley bearing play and drag by
rotating the rotor pulley by hand. Beplace the
clutch set with a new one if it is noisy or has
excessive play/drag (see page 21-49).
Measure the clearance between the rotor pulley (A)
and the armature plate (B) all the way around. lf the
clearance is not within specified limits, remove the
armature plate (see page 21-49) and add or remove
shims as needed to increase or decrease clearance.
Clearance: 0.510.15 mm {0.02010.006 in.)
NOTE: The shims are available in four thicknesses:
0.1 mm.0.2 mm,0.4 mm, and 0.5 mm.
21-48
a
4. Release the field coil con nector f rom the holder,
then disconnect it. Check the thermal protector for
continuity. lf there is no continuity, replace the
thermal protector (see page 21-51).
NOTE: The thermal Drotector will have no
continuity above 252to270"F \122lo 132'C). When
the temperature drops below 241 to 219'F (116 to
104'C), the thermal protector will have continuity.
Check resistance of the field coil. lf resistance is not
within specifications, replace the field coil
(see page 21-49).
Field Coil Resistance: 3.05 3.35ohmsat68"F
t20"c)
,\.
Compressor Clutch Overhaul
Special Tool Required
A,/C clutch holder, Robinair 10204. Kent-Moore J37872,
or Honda Tool and Equipment KMT-J33939,
commercially available
1. Remove the center nut (A) while holding the
armature plate with a commercially available A,/C
clutch holder (B).
17.6 N.m{1.8 kgf.m,13 tbt.ft)
Remove the armature plate (A) and shim(s) (B),
taking care not to lose the shim(s). lf the clutch
needs adjustment, increase or decrease the
number and thickness of shims as necessary, then
reinstallthe armature Dlate, and recheck its
clearance (see page 21-481.
NOTE: The shims are available in four thicknesses:
0.1 mm,0.2 mm,0.4 mm, and 0.5 mm.
9-=-g
3. lf you are replacing the field coil, remove the snap
ring (A) with snap ring pliers, then remove the rotor
pulley (B). Be careful not to damage the rotor pulley
or tne compressor.
4. Remove the bolt and holder (A). then disconnect
the field coil connector (B). Loosen the clamp screw(C) to iree the field coil wire. Remove the snap ring
{D)with snap ring pliers, then remove the field coil(E). Be careful not to damage the field coil or the
comoressor.
\ot
-@
/@h"
.ffi
7.4 N.m(0.75 kgf m,5 tbf.ft)---------------- ")
(cont'd)
21-49
System Charging
Air conditioning refrigerant or lubricant vapor
can irritate your eyes, nose, or throat.
Be carefulwhen connecting service equipment.
Do not breathe refrigerant or vapor,
Use only service equipment that is U.L.'listed and is
certified to meet the requirements of SAE J2210 to
remove HFC-134a {R-134a) from the air conditioning
system.
lf accidental system discharge occurs, ventilate the
work area before resuming service
Additional health and safety information may be
obtained from the refrigerant and lubricant
manufacturers.
1. Connect a R-134a refrigerant recovery/recycling/
charging station (A) to the high-pressure service
pon (B) and the low-pressure service port {C), as
shown, following the equipment manufacturer's
instructions.
2.
3.
4.
Evacuate the system (see page 21'54).
Add the same amount of new refrigerant oil to the
system that was removed during recovery. Use
only KEIHIN SP-10 refrigerant oil.
Charge the system with the specified amount of
R-134a refrigerant. Do not overcharge the system;
the compressor will be damaged.
Select the appropriate units of measure for your
refrigerant charging station.
Refrigerant capacity:
500 to 550 g
0.50 to 0.55 kg
1.10 to 1.21 lbs
17.6 to 19.4 oz
Check for refrigerant leaks (see page 21'56).
Check for system performance (see page 21-58).
21-55
A/C System Tests
Pressure Test
Test resultssvmotom3DGaUSeDischarge (high)pressureabnormally high
After stopping compressor, pressure
drops quickly, and then continues toAir in systemRecover, evacuate (see page 21-54),and recharge with specified amount{see oaoe 21 55).
Beduced or no air flow throughcondenserClogged condenser or radiatorfinsCondenser or radiator fan not
CleanCheck fan voltage and rpm.Check fan direction.
Line to condenser is excessively hot.Restricted flow of refrigerant inReplace restricted lines.
Discharge pressureHigh and low pressures are balancedsoon after stopping compressor, Lowside is hioherthan normal.
. Faulty compressor dischargevalve. Faultv comoressor seal
Beplace the compressor.
Outlet of expansion valve is notfrosted, low pressure gauge indicatesFaulty expansion valveMoisture in system
. Replace the expansion valve.. Recover, evacuate for at least30 minutes, and recharge withsDecified amount.
Suction (low)pressureabnormally low
Expansion valve is not frosted, andlow-pressure line is not cold. Lowpressure gauge indicates vacuum,
' Frozen expansion valve(Moisture in system). Faulty expansion valve
Recover, evacuate for at least30 minutes, and recharge withspecified amount.Beplace the expansion valve.
Discharge temperature is low, and theair flow from vents is restricted.Frozen evaporatorRun the fan with compressor off, thencheck evaooratot temoerature sensor.
Exoansion valve is frosted.ean or reolace,
Receivetdryer outlet is cool, and inletis warm (should be warm duringooeralton),
Clogged receiver/dryerReplace receaver/dryer.
Suction pressureabnormally highLow pressure hose and check joint arecooler than the temperature aroundevaoorator,
Expansion valve open too longBepair or replace.
Suction pressure is lowered when..nrlenser is cooled bv water.Excessive refrigerant in systemRecover, evacuate, and recharge withqnp.ifie.lamo'rnr
High and low pressure are equalizedas soon asthecompressor is stopped,and both gauges fluctuate while
Faulty gasketFaulty high pressure valveForeign panicle stuck in high
Replace the compressor.
Suction anddaschargepressuresabnormallv hioh
Reduced air flow through condenser.. Clogged condenser or radiatorfins' Condenser or radiator fan notworkino orooerlv
CleanCheck voltage and fan rpm.Check fan direction.
Suction anddischarge pressureabnormally low
Low-pressure hose and metalendareas are coolerthan evaoorator,Clogged or kinked low-pressurehose oartsRepair or replace.
Temperature around expansion valveis too low compared with that aroundClogged high-pressure lineRepair or replace,
Fefrigerant leaks:omoressor clulch is dirtv.:omoressor shaft seal leakinqReolace the comDressor,
lomoressor bolt(s) are dirtv.no around bolt(s)Tiohten bolt{s) ot reolace comDressor,
;omDressor oasket is wet with oil.ietnoace the comoressor.
(cont'd)
21-57
Gauges
Self-diagnostic Procedure
The gauge assembly has a self-diagnosis function.. The Beeper Drive Circuit Check. The Indicator Drive Circuit ChecL. The LCD Segments Check. The Gauges Drive Circuit Check (Speedometer, Tachometer, Fuel gauge, Coolant temperature gauge). The Communication Line Check (the coolanttemperature signal line between the gauge and ECM)
NOTE: Indicators are also controlled via the communication line.
Entering the self-diagnosis f unction:
Before doing the self-diagnosis function, check the No. 9 (10A) fuse in the under-hood fuse/relay box and No. 10 {7.5A)fuse in the under'dash fuse/relay box.
1. Push and hold the trip/reset button.
2. Turn the lighting switch ON.
3. Turn the ignition switch ON (ll).
4. Within 5 sec., turn the lighting switch OFF, then ON and OFF again.5. Within 5 sec., release the trip/reset button, then push and release the button four times reDeatedlv.
NOTE:. While in the self-diagnosis mode, the dash lights brightness controller operates normally.'Whileintheself-diagnosismode,thetrip/resetbuttonisusedtostartthebeeperdrivecircuitcheckandthegauge
drive cicuit check.. lf the vehicle speed exceeds 1.2 mph 12 km/h) orthe ignition switch is tu rned OFF, the self,diag nosis mode ends.
oN flrl
lgnition
Switch
Lighting
Switch
Trip/Reset
Switch-> Move to selt-diagnosis mode.
5 sec.5 sec.
The Beeper Drive Circuit Check:
When entering the self-diagnosis mode, the beeper sounds five times
The Indicator Drive Circuit Check:
When entering the self-diagnosis mode, the following indicators blink.
Seat belt indicator, Door/hatch indicator, Brake system, Lowfuel indicator, Maintenance required indicator (USA),
Washer fluid level indicator (Canada), Oil pressure light.
v
OFF
22-56