1987 MAZDA 626 Workshop Manual

TROUBLESHOOTING (G4A-EL) 7B
STEP 6 (OIL PRESSURE TEST)
This step checks line pressures for checking the hydraulic components and for oil leakage.
Line Pressure Test
Preparation
1. Perform the preparation procedure shown in STEP 4 (STALL TEST).
2. Connect a tachometer to the engine.
3. Connect the SST to the line pressure inspection hole (square head plug L)
Procedure
76G07B-031
1. Start the engine and check the idle speed in P range
Idle speed: 900 -so rpm
2. Shift the selector lever to D range and read the line pressure at idle.
3. Depress the brake pedal firmly with the left foot and gradually depress the accelerator pedal with
the right foot.
4. Read the line pressure as soon as the engine speed becomes constant, then release the accelera-
tor pedal.
Caution
Steps 3 to 4 must be performed within 5 seconds.
5. Shift the selector lever to N range and run the engine at idle for at least one minute.
6. Read the line pressure at idle and engine stall speeds for each range in the same manner.
7B—31

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-EL) 7B
Throttle Pressure Test
This step checks line pressure for checking the hydraulic components and for improper adjustment
of throttle cable.
Preparation
1. Perform the preparation procedure shown in STEP 4 (STALL TEST).
2. Connect a tachometer to the engine.
3. Connect the SST to the throttle pressure inspection hole (square head plug T).
Procedure
76G07B-034
1. Start the engine and check the idle speed in P range.
Idle speed: 900 _5o rpm
2. Shift the selector lever to D range and read the throttle pressure at idle.
3. Depress the brake pedal firmly with the left foot and gradually depress the accelerator pedal with
the right foot.
4. Read the throttle pressure as soon as the engine speed becomes constant, then release the ac-
celerator pedal.
Caution
Steps 3 to 4 must be performed within 5 seconds.
Specified throttle pressure:
Throttle pressure kPa (kg/cm2, psi)
When idling 39-88 (0.4—0.9, 6—13)
At stall speed 471—589 (4.8—6.0, 68—85)
Evaluation
Throttle pressure Possible location of problem
Not within specification
Throttle valve sticking Pressure regulator valve sticking Improper adjustment of throttle cable
7B—33

7B TROUBLESHOOTING (G4A-EL)
STEP 7 (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 electronic system component or mechanical sections.
Caution
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 select the Power mode.
2. Accelerate the vehicle with half and full throttle valve opening.
Note
Throttle sensor voltage of the EC-AT Tester represents the 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 (Power) shift diagram.
Note
a) Drum speed (rpm) of the EC-AT Tester represents the shift point.
b) Vehicle speed of the EC-AT Tester and speedometer and vehicle speed on a chassis
roller may not meet the specified shift pattern because of tire size. Therefore, check
the shift points with the Drum speed.
c) There is no lock-up when the coolant temperature is below 72°C (162°F).
d) There is no overdrive when the cruise control is operating and there is a 3 km/h (1.9
mph) difference between the pre-set cruise speed and vehicle speed, or set or resume
switch is ON.
e) There is no lock-up when the brake pedal is depressed.
4. Check the up-shifts for shift shock or slippage in the same manner.
5. While driving in OD, shift the selector lever to S range and check that 4-3 downshift immediately
occurs, then decelerate and check that engine braking effect is felt in only 3rd gear.
7B—34

TROUBLESHOOTING (G4A-EL) 7B
Economy
4.3 (8/8)
3.8-(11/8)
3.4-I .^(6/8)
& c 2.9 5 8.(5/8) - °
S 5 2.4H 1 -i (4/8) « >
0) 1.0-(1/8)
05 A
(0/8)
0
i
Lock-up OFF
40 (25) 60 (37) 80 (50) 100 (63) 120 (74) 140 (87) 160 (99)
Vehicle speed km/h (mph)
6. Select D range (Hold mode).
7. Accelerate the vehicle and check 2-3 up- and down-shifts, no 1st, and no OD is obtained and that
the 2-3 shift points are as shown in the D range (Hold) shift diagram.
79G07C-094
7B—35

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