1987 MAZDA 626 torque

TROUBLESHOOTING (G4A-EL) 7B
7. Perform the stall test for the following ranges in the same manner.
(1) D range (4) L range
(2) D range (Hold) (5) L range (Hold)
(3) S range (Hold)
Caution
Be sure to allow sufficient cooling time between each stall test.
Engine stall speed: D.S.L range 2170—2270 rpm
R range 2130—2230 rpm
Note
The stall test can be performed with the EC-AT Tester in place of a tachometer.
Drum stall speed indication: 0 rpm
76G0/B-029
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 transmission case
Stuck pressure regulator valve
Above specification
In forward ranges Forward clutch slipping One-way clutch 1 slipping
Above specification
In D range One-way clutch 2 slipping
Above specification
In S (Hold) and L (Hold) ranges Coasting clutch slipping
Above specification In D (Hold) and S (Hold) ranges 2-4 brake band slipping Above specification
In R, L and L (Hold) ranges Low and reverse brake slipping
Above specification
In R range
Low and reverse brake slipping Reverse cluch slipping Perform road test to determine whether problem is low and reverse brake or reverse clutch
a) Engine brake applied in 1st ...Reverse clutch
b) Engine brake not applied in 1st ...Low and reverse brake
Within specification All shift control elements within transmission are func-
tioning normally.
Below specification
Engine out of tune
Below specification One-way clutch slipping within torque converter
86U07B-036
7B-29

7B TROUBLESHOOTING (G4A-EL)
Evaluation
Condition Possible Cause
No 1-2 up- or down-shift Stuck 1-2 shift solenoid valve
Stuck
1
-2 shift valve
No 2-3 up- or down-shift Stuck 2-3 shift solenoid valve Stuck 2-3 shift valve
No 3-OD up- or down-shift Stuck 3-4 shift solenoid valve Stuck 3-4 shift valve
No lock-up shift Stuck lock-up control solenoid valve Stuck lock-up control valve
Incorrect shift point Mis-adjusted throttle sensor Sticking shift valves
Excessive shift shock or slippage
Excessive shift shock Stuck accumulators Stuck or no one-way check orifice
Worn clutches, brakes, or one-way clutch
No engine braking effect Worn clutches or brakes
76G07B-035
Noise and vibration
Drive the vehicle in OD (lock-up), OD (no lock-up), 3rd (Hold) 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, OD->1,
3->2, 3-+1, 2-> 1, and the shift points are as shown in the shift diagram.
S Range Test
Shift pattern
1. Shift the selector lever to S range and select the Economy mode.
2. Accelerate the vehicle and check that 1-2 and 2-3 up-shifts and down-shifts are obtained, and that
no overdrive and no lock-up are obtained.
Note
a) Inspections of shift shock and shift point are not necessary because these are the same
as those of the D Range Test.
b)ln S range, the shift patterns for Economy and Power modes are the same.
c) Shift points are the same as those of the D range (Power) shift diagram.
3. While driving in S range (Economy mode) and 3rd gear, select the Hold mode and check that 3rd
gear is held until the 3-2 down-shift point as shown in the S range (Hold) shift diagram is achieved.
4. Accelerate the vehicle with S range (Hold mode) and check that 2nd gear is held.
7B i—36

TROUBLESHOOTING (G4A-EL) 7B
76G07B-036
Noise and vibration
Drive the vehicle in 2nd gear (Hold mode) 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.
L Range Test
Shift pattern
1. Shift the selector lever to L range and select the mode.
2. Accelerate the vehicle and check that the 1-2 up- and down-shiftings are obtained and that no 3rd
gear, no OD, and no lock-up are obtained.
Note
Inspection of shift shock and shift point are not necessary because these are the same
as those of the D Range Test.
3. Drive in 1st gear then decelerate and check that engine braking effect is felt.
Note
a) In L range, the shift patterns for Economy and Power modes are the same.
b) Shift points are the same as those of the D range (Power) shift diagram.
4. While driving in S range (Hold mode) and 2nd gear, shift the selector lever to L range and check
that 2nd gear is held until the 2-1 down-shift point as shown in the L range (Hold) shift diagram
is achieved.
5. Accelerate the vehicle in L range (Hold mode) and check that 1st gear is held.
7B—37

7B TROUBLESHOOTING (G4A-EL)
86U07B-044
Noise and vibration
Drive the vehicle in 1st gear (Hold mode) 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.
7B-38

7B TROUBLESHOOTING (G4A-EL)
Slippage Test
This step is performed to inspect slippage of the friction elements.
Preparation 1. Perform the preparation procedure shown in STEP 4 (STALL TEST). 2. Connect a tachometer to the engine and set it in the cabin.
3. Connect the EC-AT Tester and the adaptor harness between the EC-AT control unit and wiring
harness.
Procedure
Drive the vehicle in each of the gears indicated below and check whether the vehicle speed or engine
speed is above or below specification excessively as shown by the drum speed.
Driving condition
Speed
Drum speed (rpm)
No. Gears Other condition Speed
1,000 2,000 3,000 4,000
1 1st L range, Hold mode 11 (7) 22 (14) 33 (20) 44 (27)
2 1st D range, Economy mode 11 (7) 22 (14) 33 (20) 44 (27)
3 2nd S range, Hold mode Vehicle speed km/h (mph) 20 (12) 40 (25) 60 (37) 80 (50)
4 3rd D range, Hold mode 31 (19) 61 (38) 92 (57) 123 (76)
5 OD D range, Economy
mode 44 (27) 88 (55) 131 (81) 173 (107)
6 OD D range, Economy mode, Lock-up Engine speed (rpm) 1,000 2,000 3,000 4,000
76G07B-038
Evaluation
When there is no malfunction in the electrical system or hydraulic system, but vehicle speed or engine
speed is below specification, the problem can be attributed to slippage of the friction elements.
Driving conditions below specification Possible Cause
No.1 condition only Low and reverse brake
No.2 condition only One-way clutch
No.3 condition only 2-4 brake band
No.4 condition only Coasting clutch
No.5 condition only 3-4 clutch
No.1-No,5 conditions Forward clutch
No.6 condition only Lock-up piston (in torque converter)
76G07B-039
7B—40

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
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

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