transaxle MAZDA 626 1987 Repair Manual

7B TROUBLESHOOTING (G4A-EL)
Specified line pressure:
Line pressure kPa, (kg/cm2, psi)
Range DSL R
When idling 353-432 (3.6-4.4, 51-63) 598—942 (6.1-9.6, 87—137)
At stall speed 873-1040 (8.9-10.6, 127-151) 1668-2011 (17.0-20.5, 242-292)
76G07B-032
Evaluation
Line pressure Possible location of problem
Low pressure in every position
Worn oil pump
Fluid leaking from oil pump, control valve body, or transaxle case
Pressure regulator valve sticking
Low pressure in D and S only Fluid leaking from hydraulic circuit of forward clutch
Low pressure in R only Fluid leaking from hydraulic circuit of low and reverse brake
Higher than specification
Throttle valve sticking
Throttle modulator valve sticking
Pressure regulator valve sticking
76G07B-033
7B—32

TROUBLESHOOTING (G4A-HL) 7B
TROUBLESHOOTING (G4A-HL)
GENERAL NOTE
In the event of a problem with the automatic transaxle, the cause may be in the engine, power train,
hydraulic control system, or electrical control system.
When troubleshooting, therefore, it is recommended to begin from those points that can be judged
quickly and easily. The recommended troubleshooting sequence is described below.
STEP 4: TIME LAG TEST
Check time lag of oil pressure supply
STEP 6: OIL PRESSURE TEST Check line, throttle, and governor pressures
This step checks conditions surrounding the automatic
transaxle.
This step checks the electrical control system.
• Function of the electrical control system
• Components
This step checks the power train. • Friction element slipping • Torque converter capacity
This step checks operation of the hydraulic control system. • Accumulators • Friction elements slipping • Regulating valves
This step checks functions of the electric control system and
hydraulic control system.
This step checks major points of the hydraulic control system.
• Oil pump • Line pressure control • Throttle pressure control
• Governer pressure control
STEP 5: ROAD TEST Check items on road test
• Shift point • Shift schedule
• Kick-down • Shift shock • Lock-up and overdrive inhibition
By following the above 6 steps, the cause of the problem should be located.
As another guide to faster location of the causes of problems, the Quick Diagnosis Chart is included
at pages 7B—42, 43.
In this chart, a circle is used to indicate the components that might be the cause of trouble for 20
types of problems. It is only necessary to check those components indicated by circles, at each step
of the troubleshooting process, in order to quickly locate the cause of the problem.
76G07B-040
7B—41

TROUBLESHOOTING (G4A-HL) 7B
-ON VEHICLE-OFF VEHICLE-
Accele-rating
Shifting
Slipping
Inspection point and reference page
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Vehicle does not move in D, 2, 1, or R range
Vehicle moves in N
range
Excessive creep
No creep at all
No shift
Abnormal shift
sequence
Frequent shifting
Excessive high or low shift point
No lock-up
No kick-down
Engine run away or slip when starting vehicle
Engine run away or slip when up- or down-shifting
Excessive N to D or N to R shift shock
Excessive shift shock when upshifting or downshifting
Excessive shift shock when changing range
Transaxle noisy in N or
P range
Transaxle noisy in
D, 2, 1, or R range
No engine braking
Transaxle
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76G07B-042
7B—43

7B TROUBLESHOOTING (G4A-HL)
STEP 1 (PRELIMINARY INSPECTION)
In this step, the fundamental points related to the automatic transaxle are checked. These points must
be kept in the correct condition at all times in order to assure proper operation of the automatic transaxle.
83U07B-025
1. Automatic Transaxle Fluid (ATF)
Check ATF level and condition. (Refer to page
7B-71)
76G07B-043
11
m
0 £
m
0 •
o #
m
Button need not
^ be depressed
Button must be pressed
2. Selector Lever
Check selector lever position and adjust if neces-
sary. (Refer to page 7B—72)
76G07B-044
3. Oil Leakage
Check for oil leakage.
(1) Warm up the ATF.
(2) Apply the parking brake and block the wheels
to prevent the vehicle from rolling.
(3) Shift the selector lever to R range.
(4) Check if oil leaks from the following oil seals
or gaskets.
(5) If oil leaks, replace the oil seal or gasket.
76G07B-215
7B—44

TROUBLESHOOTING (G4A-HL) 7B
The following figure shows the locations where fluid leakage may possibly occur.
1. Oil pan
2. Control valve body cover
3. Oil pump
4. Inhibitor switch
5. Speedometer driven gear
6. Oil filler tube
7. Throttle cable
8. Governor cover
9. Bearing cover
10. Driveshaft
11. Square head plug
12. Transaxle case
13. Drain plug
14. Oil cooler return pipe
15. Oil cooler outlet pipe
16. Blind plugs
83U07B-028
4. Inhibitor Switch
Check the inhibitor switch for operation. (Refer to
page 7B—65)
76G07B-045
7B—45

TROUBLESHOOTING (G4A-HL) 7B
Evaluation
Condition Possible cause
Above specification
In all ranges Insufficient line pressure
Worn oil pump
Above specification
In all ranges Insufficient line pressure Oil leakage from oil pump, control valve, and/or transaxle case
Stuck pressure regulator valve
Above specification
In D 2, and 1 One-way clutch 1 slipping
Above specification
In D range only One-way clutch 2 slipping
Above specification In 2 range only 2-4 brake slipping Above specification
In R range only
Low and reverse brake slipping
Above specification
In R range only
Reverse clutch slipping
Above specification
In R range only Perform a road test, to determine if this is caused by the low and reverse brake or the reverse clutch, as follows:
a) Effective engine braking in 1 range Front clutch
b) No engine braking in 1 range Low and reverse brake
Within specification All shift control elements within transaxle are functioning
normally.
Below specification
Engine out of tune
Below specification One-way clutch slipping within torque converter
76G07B-055
7B—51

TROUBLESHOOTING (G4A-HL) 7B
Specified Line pressure:
Condition Line pressure kPa (kg/cm2, psi)
Range DSL R
When idling 350-490 (3.6-5.0, 51-71) 600-830 (6.1-8.5, 87-121)
At stall speed 980-1230 (10.0—12.5, 142—178) 1470-1960 (15.0-20.0, 213-284)
76G07B-063
Evaluation
Condition Possible Cause
Below specification
In all ranges
Worn oil pump
Below specification
In all ranges
Fluid leakage from the oil pump, control valve body
and/or transaxle case
Below specification
In all ranges Stuck pressure regulator valve
Below specification
In all ranges
Stuck throttle valve
Below specification
In all ranges
Stuck pressure modulator valve
Below specification
In D, 2 and 1 range
Fluid leakage from the forward clutch hydraulic circuit
Below specification
In D, 2 and 1 range Fluid leakage from the governor valve hydraulic circuit
Below specification
In D, 2 and 1 range
Fluid leakage from the N-R accumulator seal rings
Below specification In D and 1 range Fluid leakage from the 2-3 accumulator seal rings Below specification In D and 1 range Fluid leakage from the 1-2 accumulator seal rings Below specification
In D and R range Fluid leakage from the N-D accumulator seal rings
Below specification
In 2 and 1 range Fluid leakage from the coasting clutch hydraulic circuit
Below specification
In 2 and 1 range Stuck throttle backup valve
Below specification
In R and 1 range Fluid leakage from the low and reverse brake hydraulic
circuit
Below specification
In 2 range only Fluid leakage from 2-4 brake servo hydraulic circuit
Below specification
In 1 range only Stuck low reducing valve
Below specification
In R range only Fluid leakage from reverse clutch hydraulic circuit
Excessive line pressure
Stuck throttle valve
Excessive line pressure Stuck throttle modulator valve Excessive line pressure Stuck pressure regulator valve Excessive line pressure
Stuck throttle backup valve
76G07B-216
7B—59

7B ELECTRICAL SYSTEM COMPONENTS
76G07B-079
76G07B-080
76G07B-081
PULSE GENERATOR (G4A-EL)
Inspection
1. Disconnect the pulse generator connector.
2. Check for continuity between the terminals, if
necessary replace the pulse generator.
Resistance: 200—400fl
VEHICLE SPEED SENSOR (G4A-EL)
Inspection of voltage
1. Connect a voltmeter between the 1Q terminal of
the EC-AT control unit and ground as shown.
2. Turn the ignition switch ON.
3. Remove the speedometer cable from the transaxle.
4. Slowly turn the speedometer cable one turn.
5. Check that approx. 4.5V is shown 4 times.
6. If not correct, check the combination meter.
CRUISE CONTROL SWITCH (CRUISE CONTROL
UNIT)
Refer to Section 15.
IDLE SWITCH AND THROTTLE SENSOR
(G4A-EL)
Refer to Section 4A.
OD RELEASE SOLENOID VALVE (G4A-HL)
Inspection of Resistance
1. Disconnect the solenoid valve connector.
2. Check resistance between the terminals.
Resistance: 13—27 ft
3. If not correct, replace the solenoid valve.
76G07B-082
7B-68

ON-VEHICLE MAINTENANCE 7B
ON-VEHICLE MAINTENANCE
AUTOMATIC TRANSAXLE FLUID (ATF)
Inspection for Fluid Leaks
Check for fluid leaks; the following figure shows the locations where fluid leakage may possibly occur.
1. Oil pan
2. Control valve body cover
3. Oil pump
4. Inhibitor switch
5. Speedometer driven gear
6. Pulse generator (G4A-EL)
7. Oil filler tube
8. Throttle cable
9. Bearing cover
76G07B-085
10. Driveshaft
11. Square head plug
12. Transaxle case
13. Drain plug
14. Oil cooler return pipe
15. Oil cooler outlet pipe
16. Fluid temperature switch (G4A-EL)
17. Blind plugs
18. Governor cover (G4A-HL)
Inspection of Level
1. Apply the parking brake and position wheel chocks
to prevent the car from rolling forward.
Note
Place the car on a flat, level surface.
2. Run the engine so that the automatic transaxle fluid
reaches specified temperature.
3. While the engine is idling, shift the select lever from
P to L or P to 1 and back again.
4. Let the engine idle.
5. Shift the select lever to P.
76G07B-086
7B—71

7B ON-VEHICLE MAINTENANCE
86U07B-064
86U07B-065
t «
•A
0 0
0 »
LX] O 9
m
(2)

(1)

Button need not
be depressed
Button must be pressed
76F07B-022
6. Ensure that the ATF level is between the F and L
marks. Add ATF to specification, if necessary.
Low temperature scale:
20°C (68°F)
High temperature scale:
65°C (149°F)
ATF type:
Dexron II or M HI
Inspection of Condition
1. Check the ATF for discoloration.
2. Check the ATF for any unusual smell.
Note
Determine whether or not the automatic trans-
mission should be disassembled by observ-
ing the condition of fluid carefully.
If the fluid is muddy and varnished, it indicates
burned drive plates.
SELECTOR LEVER
Inspection
1. Check that the selector lever can only be shifted
as shown in the figure.
2. Make sure there is a click at each range when shift-
ed from P <-> L or P <-» 1 range.
3. Check that the position of the selector lever and
the indicator are exact.
4. Check that the button returns smoothly when used
to shift the selector.
Adjustment
1. Loosen locknuts A, B, and lockbolt C.
2. Shift the selector lever to P range.
3. Shift the transaxle to P range by moving the man-
ual shaft of the transaxle.
4. While holding the selector lever forward in P range,
tighten lockbolt C to the specified torque.
Tightening torque:
8—11 N-m (80—110 cm-kg, 67—95 in-lb)
76F07B-023
7B—72