1987 MAZDA 626 Workshop Manual

TROUBLESHOOTING (G4A-HL) 7B
STEP 2 (ELECTRICAL SYSTEM INSPECTION)
In this step, the function of the electrical control system (Inhibition of OD and lock-up) is checked. The
electrical control system components should be checked to determine if it functions correctly.
76G07B-048
O/D OFF Switch Inhibition Function
1. Warm up the engine and ATF.
2. Check that the D range, OD, and lock-up is
provided.
3. When driving the vehicle with D range, OD, and
lock-up selected, depress the O/D OFF switch and
check that OD and lock-up is cancelled.
4. If not cancelled, check the O/D OFF switch.
5. Release the O/D OFF switch after completion.
Cruise Control Switch Inhibition Function
1. Drive the vehicle in D range, OD, and lock-up
selected again.
2. Depress the Set switch of the cruise control and
check that OD and lock-up is cancelled.
3. If not cancelled, check the cruise control system.
4. Again drive the vehicle in D range, OD, and
lock-up.
5. Turn the Resume switch of the cruise control and
check that OD and lock-up is cancelled.
6. If not cancelled, check the cruise control system.
76G07B-051
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7B TROUBLESHOOTING (G4A-HL)
76G07B-052
Water Temperature Switch Inhibition Function
1. Stop the vehicle.
2. Disconnect the water temperature switch con-
nector.
3. Drive the vehicle in D range selected.
4. Check that OD and lock-up does not operate.
5. If not cancelled, check the wiring harness of the
water temperature switch.
6. Stop the vehicle and reconnect the water temper-
ature switch connector.
Kick-down Switch Inhibition Function
1. Connect the terminals of the kick-down switch con-
nector with a jumper wire.
2. Drive the vehicle in D range selected.
3. Check that the OD and lock-up do not achieve.
4. If not correct, check wiring harness of kick-down
switch.
5. Stop the vehicle and reconnect the connector to
the switch.
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TROUBLESHOOTING (G4A-HL) 7B
STEP 3 (STALL TEST)
This step is performed to determine if there is slippage of the friction elements or malfunction of the
hydraulic components.
Preparation
Check the following items prior to testing:
1. Engine coolant, engine oil and ATF levels.
2. Warm the engine thoroughly to raise the ATF temperature to operating level (50—80°C, 122—176°F).
3. Engage the parking brake and use wheel chocks at the front and rear wheels.
Pull the parking brake Water temperature
ATF
83U07B-038
7B—49

7B TROUBLESHOOTING (G4A-HL)
Procedure
76G07B-054
1. Connect a tachometer to the engine.
2. Shift the selector lever to D range.
3. Depress the brake pedal firmly with the left foot and gradually depress the accelerator pedal with
the right foot.
4. Read and note the engine speed as soon as it becomes constant, then release the accelerator pedal.
Caution
Steps 3 to 4 must be performed within 5 seconds.
5. Shift the selector to N range and run the engine at idle speed for at least one minutes.
Note This one minute idle period is performed to cool the ATF and prevent oil degradation.
6. Perform stall tests for the following ranges in the same manner.
(1) 2 range
(2) 1 range
(3) R range
Standard stall speed:
FE engine F8 engine
D.S.L range 2430—2530 rpm D.S.L range 2180—2280 rpm
R range 2390—2490 rpm R range 2140—2240 rpm
Caution
Always provide adequate cooling time between individual range stall tests.
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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
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7B TROUBLESHOOTING (G4A-HL)
STEP 4 (TIME LAG TEST)
If the selector lever is shifted while the engine is idling, there will be a certain time lapse, or time lag,
before shock is felt. This step checks this time lag for checking the condition of the N-D and N-R ac-
cumulators, forward, reverse and one-way clutches, and low and reverse brake.
Preparation
Perform the preparation procedure shown in the STEP 3 (STALL TEST).
Procedure
1. Start the engine and check that the idle speed is 900 l5o rpm.
2. Shift from N range to D range
3. Measure the time it takes from shifting until shock is felt using a stop watch.
4. Shift the selector to N range and run the engine at idle speed for at least one minute.
5. Perform the test for the shift from N range to R range in the same manner.
Note
Make three measurements for each test and take the average value.
Specified time lag: N -> D range 0.4—1.2 second
N -> R range 0.4—1.5 second
Evaluation
Condition Possible Cause
N D shift
More than specification
Insufficient line pressure
N D shift
More than specification Forward clutch slipping
N D shift
More than specification One-way clutch 1 slipping N D shift
More than specification
One-way clutch 2 slipping N D shift
Less than specification N-D accumulator not operating properly
N D shift
Less than specification Excessive line pressure
N-R shift
More than specification
Insufficient line pressure
N-R shift
More than specification Low & reverse brake slipping
N-R shift
More than specification
Reverse clutch slipping N-R shift
Less than specification N-R accumulator not operating properly
N-R shift
Less than specification Excessive line pressure
76G07B-056
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TROUBLESHOOTING (G4A-HL) 7B
STEP 5 (ROAD TEST)
This step is performed to inspect for problems at the various ranges.
If
these tests show any problems,
adjust or replace by referring to the mechanical sections.
Perform the test at normal ATF operating temperature (50—80°C, 122—176°F).
D Range Test
Shift point, shift pattern, and shift shock
1. Shift the selector lever to D range and depress the OD OFF switch.
2. Accelerate the vehicle with half (4/8) and full (8/8) throttle valve opening.
3. Check that 1-2, 2-3 and 3-OD up-shifts and downshifts and lock-up are obtained. The shift points
must be as shown in the D range shift diagram.
Note
a) Vehicle speed on a chassis roller may not meet the specified shift diagram because of
tire size.
b) There is no lock-up or OD when the coolant temperature is below 72°C (162°F), and when
the OD OFF switch is depressed.
4. Check the up and down shifts for shift shock or slippage.
5. While driving in 3rd (50—60 km/h, 31—37 mph) shift the selector lever to 2 range and check that
3-2 downshift immediately occurs, then decelerate and check that engine braking effect is felt in
2nd gear.
D range shift diagram
FE engine
Caution
8/8 n
-OD
0 20(12) 40(25) 60(37) 80(50) 100(63) 120(74) 140(87)
Vehicle speed km/h (mph)
76GC7B-057
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7B TROUBLESHOOTING (G4A-HL)
Noise and vibration
Drive the vehicle in OD (lock-up), OD (no lock-up), 3rd and check for abnormal noise or vibration.
Note
Abnormal noise and vibration can also be caused by the torque converter, drive shaft, or
differential. Therefore, checking of cause must be made with extreme care.
Kick-down
Drive the vehicle in OD, 3rd and 2nd gears and check that kick-down occurs for OD-*3, OD->2, 3-*2,
3->1, 2-> 1, and the shift points are as shown in the shift diagram.
2 Range Test
Shift pattern
1. Shift the selector lever to 2 range.
2. Accelerate the vehicle in 2 range and check that 2nd gear is held.
Noise and vibration
Drive the vehicle in 2nd gear and check for abnormal noise or vibration.
Note
Abnormal noise and vibration can also be caused by the torque converter, drive shaft or
differential. Therefore, checking of cause must be made with extreme care.
7B—54