1987 MAZDA 626 check engine

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
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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.
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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
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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
7B-52

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)
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7B—53

TROUBLESHOOTING (G4A-HL) 7B
1 Range Test
Shift pattern
1. Shift the selector lever to 1 range.
2. Accelerate the vehicle with half (4/8) and full (8/8) throttle valve opening.
3. Check that the 1-2 up- and down-shifts are obtained and that no 3rd gear, no OD, and no lock-up
are obtained. The shift points must be as shown in the 1 range shift diagram.
Note
Vehicle speed on a chassis roller may not meet the specified shift diagram because of tire
size.
4. Check the up and down-shifts for shift shock or slippage.
5. Drive in 1st gear then decelerate and check that engine braking effect is felt.
1 range shift diagram
FE engine
8/8-1 i
7/8-
6/8-2
2 CT>
I 4/8-a> a. o a> 3/8-
o
2/8-
1/8-
20 40 60 80 (25) (37) (50)
Vehicle speed km/h (mph)
80 100 120 140 (63) (74) (87) (12)
76G07B-059
7B—55

7B TROUBLESHOOTING (G4A-HL)
F8 engine
8/8-1
7/8-
6/8- O) I
i ! O) Q.
o 3/8- [ ^ I o
jE 2/8-1 I
1/8- |
0/8 ' 1 ' 1 ' 1 1 1 1 1 1— ' l 0 20 40 60 80 100 120 140 (12) (25) (37) (50) (63) (74) (87)
Vehicle speed km/h (mph)
76G07B-060
Noise and vibration
Drive the vehicle in 1st 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.
P Range Test
1. Shift into P range on a gentle slope, release the brake and check that the vehicle does not roll.
2. Shift into P range while driving the vehicle at maximum of 4 km/h (2.5 mph) on a level surface,
and check that the vehicle stops.
Vehicle Speed at Gearshift Table
Range Throttle condition Shifting Vehicle speed km/h (mph) Range Throttle condition Shifting FE engine F8 engine
D
Fully opened 1st ->• 2nd 50-65 (31-40) 47-62 (29-38)
D
Fully opened 2nd - 3rd 100-115 (62-71) 94-109 (58—68)
D
Half throttle (1/2)
1st - 2nd 17-32 (11-20) 16—31 (10—19)
D
Half throttle (1/2) 2nd -> 3rd 42-57 (26-35)
D
Half throttle (1/2) 3rd -> OD 79-94 (49-58) 74-89 (46-55)
D
Half throttle (1/2)
Lock-up 74-89 (46-55) D
Kick-down
OD - 3rd More than 88 (55) More than 82 (51) D
Kick-down
OD -> 2nd 34-103 (21-64) 33-97 (20-60)
D
Kick-down OD - 1st 27-49 (17-30) 26-48 (16-30)
D
Kick-down 3rd - 2nd 34—103 (21-64) 33-97 (20-60)
D
Kick-down
3rd - 1st
11
-49 (7—30) 10-48 (6-30)
D
Kick-down
2nd - 1st
1st - 2nd
4-49 (2-30) 3-48 (2-30)
1
Fully opened
2nd - 1st
1st - 2nd 56-71 (35-44) 52—67 (32—42)
1 Half throttle (1/2) 1st - 2nd 56-71 (35-44) 52-67 (32—42) 1
Kick-down 2nd -> 1st 46-61 (29-38) 43-58 (27-36)
D Fully opened 3rd lock-up 106-121 (66—75) 100-115 (62-71)
7B-56