1987 MAZDA 626 check engine

CRUISE CONTROL SYSTEM 1 5
B.Check Switch
The check switch in the ACC checker is used to
check the actuator operation while the engine is
running. When the check switch is held on after
the engine is started, the engine speed increases
to approximately 2,000 to 3,000 rpm and is main-
tained at that level. When the check switch is
released, the engine speed decreases to idle
speed.
76G15X-073
C.Slide switch
Before using the check switch, first move the slide
switch to the "L" position.
Then use the check switch to increase the engine
rpm.
If the engine rpm stabilizes after increasing to
2,000—3,000 rpm, there is no problem. If there is
no increase at all, or only a slight increase, try again
after setting the slide switch to the "H" position.
If there is still no increase to 2,000—3,000 rpm,
adjust the free play of the actuator inner cable.
76U15X-319
76G15X-074
Preparation
1. ACC checker installation
Depress the lock hook of the harness connector.
Remove the connector from the ACC control unit
after the ignition switch and main switch are turned
off, and then connect the harness connector to the
ACC checker.
2. Checking the free play of the actuator inner
cable
Remove the clip and adjust the nut so that the ac-
tuator control cable play is as follows when the ca-
ble is pressed lightly.
Standard play: 1—3 mm (0.039—0.118 in)
15—85

CRUISE CONTROL SYSTEM 1 5
CHECK LIGHTS (correct response)
ACTUATOR £
5 (O
W X
CHECK ITEMS AND CONDITIONS £ <0 z
VAC
CM I-1-z
Ul * < IE ffl X o V-
z o F < z ta
DC O 1-< DC Ui
TROUBLESHOOTING
(INCORRECT RESPONSE)
< S VAC UJ > < > -1 o o o UJ O
8. START THE ENGINE
• Shift lever to "N" position (A/T) O O O o X
A/T
O M/T X
O or X —
9. ACTUATOR OPERATION: (EGI model only) • After engine is started, set the slide switch "L" or "H". Then turn on check switch (keep in "D" position) Note: Engine speed should in-crease to 2,000—3,000 rpm. If over 4,000 rpm release the switch immediately.
o
X
1
o
X X X
A/T O M/T X
O or X
If engine speed does not come up to and remain
in
the
2,000
to
3,000
rpm. range, check the actuator and as-sociated harness.
10. SPEED SENSOR OUTPUT
Keeping idling condition, drive ve-
hicle slowly. o o 0 o X X 0 1 X
If GENERATOR LIGHT does not flash, trouble may be with speed sensor and associated harness.
76U15X-199
INSPECTION
Actuator
Measure the actuator solenoid resistance by using
an ohmmeter.
Check terminals Resistance
c-d
Approx. 25 to 35 ohms c — a Approx. 25 to 35 ohms
c — b
Approx. 25 to 35 ohms
76G15X-075
Cruise Control Unit
If there is an operation malfunction of the cruise con-
trol system, and no abnormal condition when check-
ing above, replace the cruise control unit and check
system operation.
Clutch Switch, Brake Switch
When removing these switches, turn each of them
so that the corresponding pedal height agrees with
the standard value.
76G15X-076
Brake pedal height: 222 ±1 mm (8.74 1820
Clutch pedal height:
216.5 ±8 mm (8.52 ±820 In)
in)
15-87

1 5 AUTO ADJUSTING SUSPENSION (AAS)
AUTO ADJUSTING SUSPENSION (AAS)
CIRCUIT DIAGRAM
Combination switch iq Speed sensor
M
Panel light
control
AAS control unit
Steering angle sensor
H
N
Check connector
IG IG
Actuator (RR)
-P-Sl
-t-^J
—Pwsl
Actuator (RL)
Actuator (FR) P5fl
+
Actuator (FL)
QO M K GIE C A
ft N J HI F D B
86U15X-151
TROUBLESHOOTING GUIDE
The AAS control unit has a self-diagnosis function detecting the unit itself, electrical parts for AAS sys-
tem, and wiring harness open circuit, to inform mechanics. If it detects their malfunctions, outputs the
output pattern to A (LW) terminal of service connector according to the settled pattern for each mal-
function.
Troubleshooting against AAS system can be conducted by knowing the output pattern (See page 15—96,
97) to detect trouble location. 76gisx-o2o
TROUBLESHOOTING
How To Use Self-Diagnosis System
By using the control unit's self-diagnosis function and
a voltmeter, malfunctions of the system are easily de-
termined. When diagnosing malfunctions, follow the
steps bellow.
1. Connect a voltmeter to A (LW) terminal of the serv-
ice connector in engine room.
2. Read out the output patterns (See page 15—96)
in following condition.
76G15X-079
15—94

OUTLINE 16
TROUBLESHOOTING GUIDE
Problem Probable cause Remedy Reference page
No blower
1. Main fuse (30
A) is
open Replace
operation
2 Malfunction
of
the blower motor Replace 3. Faulty resistor Replace 4. Malfunction
of
the blower switch Replace 5. Open
or
loose connection
in an
electrical circuit Repair 16—6,
7
Insufficient
1. Obstruction
in
the inlet
of
the blower unit Remove the obstruction 16-26
air
2. Clogged evaporator Clean the evaporator
with compressed
air
16-27 3. Frosted evaporator Check the thermostat 16-30 4. Air leakage Check for leakage
at
16-26 both sides
of
the cool-
ing unit

Compressor
1. Malfunction
of
the A/C relay Check operation 16—30
does not run,
2. Malfunction
of
the thermostat Check operation 16—30
or runs
3. Malfunction
of
the refrigerant-pressure switch Check operation 16—31
insufficiently
4.
Air
conditioner fuse (15
A)
failure Replace 5. Compressor drive belt
is
loose Readjust 16—23
6. Internal problem
of
the compressor Repair
or
replace
the
16—13
compressor 7. Battery voltage too low Recharge the battery 8. Layer short
in
the magnet coil Replace 9. Clutch face dirty with
oil
Clean
or
replace the 16-13
clutch 10. Excessive gap between the drive plate and
the
Adjust the gap 16-13
pulley
11. Open circuit
in
the magnet coil Replace 16—13
12 Open circuit Repair 16-6,
7
Refrigeration
Normal pressures are:

pressure is
High pressure
1472—1765 kPa
abnormal (15—18 kg/cm2, 214—255 psi)
Low pressure
197—294 kPa
(2—3 kg/cm2, 29—42 psi)
when: ambient temperature 35°C (95°F)
engine speed 1,500
rpm
Low pressure
1. Internal malfunction
of
the compressor Repair
or
replace the 16-13

is too high
compressor
2. Faulty contact
of
the sensing bulb
of
the expan-Repair 16-26
sion valve 3. Faulty insulation
of
the sensing bulb
of
the expan-Repair 16—26
sion valve
4. Expansion valve open too much Replace 16—26

Low pressure
1. Insufficient refrigerant Charge with refrigerant 16-8

is too low
2. Receiver-drier
is
clogged Replace 16-25
3. Expansion valve
is
clogged Replace 16-26
4. Faulty thermostat Check operation 16-30 5. Frosted piping Clean
or
replace the 16—29
piping

High pres-
1. Poor cooling
of
condenser Check and clean 16-24

sure is too
2. Loose cooling fan drive belt Readjust 16—23

high
3. Too much refrigerant Discharge the excess 16-8
refrigerant 4.
Air in
the system Evacuate and charge 16-8
the system

High pres-
1. Insufficient refrigerant Charge with refrigerant 16-8
sure is too
2. Internal malfunction
of
the compressor Repair
or
replace the 16-13

low
compressor

76G16X-004
16—5

16 OUTLINE
Sight glass
REFRIGERATION SYSTEM
Checking the Refrigerant Charge
1. Run the engine at idle.
2. Operate the air conditioner at maximum cooling
for a few minutes.
3. Check the amount of refrigerant by observing the
sight glass on the receiver-drier. (Refer to follow-
ing table.)
76G16X-005
Item Symptom Amount of refrigerant Remedy

1 Bubbles present
in
sight glass. Insufficient refrigerant. Check
for
leakage with
a gas

leak tester.
2 No bubbles present
in
sight
glass.
No
(or
insufficient) refrigerant. Refer
to
items
3
and
4.

3 No temperature difference
be-
tween compressor inlet and outlet.
System
is
empty
or
nearly empty. Evacuate and charge the sys-tem. Then check
for
leakage with
a
gas leak tester.
4 Temperature between compres-sor inlet and outlet
is
noticeably different.
Proper amount
of (or
too much) refrigerant. Refer
to
items
5
and
6.

5 Immediately after the
air
condi-tioner
is
turned off, refrigerant
in
sight glass stays clear.
Too much refrigerant. Discharge the excess refrigerant
(to the specified amount).
6 When the
air
conditioner
is

turned off, refrigerant foams and
then stays clear.
Proper amount
of
refrigerant. Refrigerant amount
is
normal.

Installation of the Manifold Gauge Set
Note:
Fittings for attaching the manifold gauge set
are on the high and low pressure pipes.
1. Close both hand valves of the manifold gauge set.
2. Install the charging hoses in the gauge set to the
fittings.
Connect the low-pressure hose to the low-pressure
gauge fitting and the high-pressure hose to the
high-pressure gauge fitting.
Tighten the hose nuts by hand.
69G16X-017
16-8

OUTLINE 16
Leak-Testing the System
After finishing the evacuation of the system, check
it for leaks.
1. Install the refrigerant container valve.
2. Open the high-pressure manual valve to charge
the system with refrigerant gas.
3. When the low-pressure gauge reads 98.1 kPa (1
kg/cm2, 14.2 psi), close the high-pressure man-
ual valve.
4. Using a halide gas leak detector, propane torch,
or electric leak detector, check the system for leaks.
If a leak is found, repair the faulty component or
connection, then evacuate the system.
76G16X-632
Charging the System
1. Close both the high- and low-pressure manual
valves completely after the system is evacuated.
2. Install the refrigerant container service valve.
3. Open the low-pressure manual valve and charge
the system with refrigerant gas.
4. When charging the system becomes difficult, run
the engine at fast idle and operate the air condi-
tioner.
Caution
Be sure to keep the container in the upright
position to prevent liquid refrigerant from be-
ing charged into the system through the suc-
tion side and possibly damaging the
compressor.
5. Charge the system to the specified amount, then
close the low-pressure manual valve.
Specified amount: 800 g (28.24 oz)
Note:
If the sight glass on the receiver-drier is free
of bubbles, the system is fully charged.
6. Close the low-pressure manual valve and the ser-
vice valve of the refrigerant container.
7. Stop the air conditioner and the engine.
8. Quickly disconnect both hoses from the gauge
fittings.
9. Put the cap nuts on the gauge fittings.
16—11

COMPRESSOR 16
69G16X-026
M10X1.25^45
Low-pressure x pressure
hose hose Compressor
COMPRESSOR
ON-VEHICLE INSPECTION
1. Connect the manifold gauge set.
2. Run the engine at 1,500 rpm.
3. Check the compressor flow:
a) High pressure is not low and low pressure is not
higher than normal.
b) Metallic sound.
c) Check to be sure that the high-pressure and low-
pressure gauges show the same value immedi-
ately after the air conditioner is switched OFF.
If both gauges show the same value immediate-
ly, it can be assumed that the gasket or the valve
inside the compressor is damaged.
4. Stop the engine.
5. Check the shaft seal and others for leakage.
6. Inspect the drive plate pulley magnetic clutch for
signs of oil.
7. Check the clearance between the drive plate and
pulley. (Refer to page 16—21.)
If any of the above checks reveal faults, repair the
compressor or magnetic clutch.
76G16X-635
Bracket No.2 Adjusting Bolt Bracket

, ,shaft

' stay _ M8XI. 25^20 MIO X 1.25 Compressor
69G16X-028
REMOVAL OF COMPRESSOR
1. Perform the Oil Return Operation. (See below.)
2. Disconnect the battery ground cable.
3. Disconnect the clutch lead wire from the wiring
harness.
4. Discharge the refrigerant from the refrigeration
system.
5. Disconnect the two flexible hoses. Plug the open
fittings immediately to keep moisture out of the
system.
6. Loosen the drive belt.
7. Remove the compressor mounting bolts and the
compressor.
Bracket No.1 M
to* 1.25

^Compressor
MIOxl. 25^110 MIOxl. 25^125
Oil Return Operation
1. If the refrigerant level is low, charge the system to
the specified amount.
2. Run the engine and air conditioner at idle and at
maximum cooling for at least 20 minutes.
76G16X-636
16—13

RECEIVER-DRIER 16
RECEIVER-DRIER
ON-VEHICLE INSPECTION
1. Use a leak detector to check the sight glass, the
fusible plug, and the fittings for leakage.
Repair or replace, if necessary.
2. Check the receiver-drier for clogging.
a) Run the engine at fast idle with the air conditioner
on.
b) Check both inlet and outlet temperatures.
If there is a great difference between the two tem-
peratures, replace the receiver-drier.
76G16X-622
Receiver-drier
Condenser bolt
76G16X-638
REMOVAL OF RECEIVER-DRIER
1. Discharge the air conditioning system.
(Refer to page 16—9)
2. Disconnect the two liquid line pipes from the
receiver-drier.
Note:
Plug the open fittings immediately to keep
moisture out of the system.
3. Remove the receiver-drier from the bracket.
INSTALLATION OF RECEIVER-DRIER
1. Install the receiver-drier onto the bracket.
Note:
Do not remove the blind plugs until ready for
connection.
2. Connect the two liquid line pipes to the
receiver-drier.
Tightening torque:
15—25 N m (1.5—2.5 m-kg, 11—18 ft-lb)
3.
If
the receiver-drier is replaced with a new one, add
compressor oil to the compressor.
Compressor oil: 10 cc (0.61 cu in)
16-25