MAZDA 626 1987 Workshop Manual

TROUBLESHOOTING (G4A-EL) 7B
Item Indication Condition Possible cause
BRAKE LIGHT SW ON Brake pedal depressed Brake light switch or
wiring BRAKE LIGHT SW
OFF Brake pedal released
Brake light switch or
wiring
WATER TEMP SW ON Coolant temperature 72°C (162°F) or above Water temp switch or wiring WATER TEMP SW
OFF Coolant temperature lower than 65°C (149°F)
Water temp switch or wiring
ATF TEMP SW ON ATF temperature 150°C (302°F) or above Fluid temperature switch or wiring ATF TEMP SW
OFF ATF temperature lower than 143°C (289°F)
Fluid temperature switch or wiring
CRUISE CONTROL SW Not used — —
Input (Digital display)
THROTTLE SENSOR
EC-AT control unit terminal voltage All the time Throttle sensor, idle switch or wirings
VEHICLE SPEED*
Vehicle speed calculated from speed sensor signal
All the time Vehicle speed sensor, speedometer cable, or wiring
DRUM SPEED* Drum speed All the time Pulse generator or wirings
Output (Light)
1-2 SOLENOID VALVE*
ON
Refer to page 7B—26 solenoid valve operation table
Control unit, 1-2 shift sol., or wiring 1-2 SOLENOID VALVE* OFF
Refer to page 7B—26 solenoid valve operation table
Control unit, 1-2 shift sol., or wiring
2-3 SOLENOID VALVE*
ON Refer to page 7B—26 solenoid valve operation table Control unit, 2-3 shift sol., or wiring 2-3 SOLENOID VALVE* OFF
Refer to page 7B—26 solenoid valve operation table Control unit, 2-3 shift sol., or wiring
3-4 SOLENOID VALVE*
ON
Refer to page 7B—26 solenoid valve operation table
Control unit, 3-4 shift sol., or wiring 3-4 SOLENOID VALVE* OFF
Refer to page 7B—26 solenoid valve operation table
Control unit, 3-4 shift sol., or wiring
LOCK-UP SOLE-NOID VALVE*
ON Lock-up condition Control unit, lock-up sol., or wiring LOCK-UP SOLE-NOID VALVE* OFF Non-lock-up condition
Control unit, lock-up sol., or wiring
HOLD INDICATOR ON Hold mode Control unit, Hold switch, or wiring HOLD INDICATOR OFF Other modes
Control unit, Hold switch, or wiring
MODE INDICATOR ON Power or economy mode Control unit, hold switch, mode switch, or wiring MODE INDICATOR
OFF Hold mode
Control unit, hold switch, mode switch, or wiring
NO LOAD SIGNAL Not used — —
76G07B-028
7B-25

7B TROUBLESHOOTING (G4A-EL)
Item Indication Condition
OUTPUT (Digital display)
1
1
st gear position
GEAR* 2 2nd gear position GEAR*
3 3rd gear position
4 Overdrive (OD) gear position
86U07B-033
Note
a) The back-up condition is as following condition
S range, hold mode, and the accelerator pedal depressed fully.
b)The * marked items should be checked during the engine running or driving.
Comprehensive Usage
The EC-AT Tester can be used to inspect slippage of friction elements, shift points, and shift sequence
during the road test.
The inspection procedure is shown in STEP 7 (ROAD TEST).
Solenoid valve operation table
RANGE GEAR SOLENOID VALVES RANGE GEAR 1-2 2-3 3-4 Lock-up
P Non ON
R Reverse ON
N Below aDDrox. 18 km/h (11 mDh) ON N Above approx. 18 km/h (11 mph) ON
1st ON ON
2nd ON ON ON
Below approx. 40 km/h (25 mph)
D 3rd Above approx. 40 km/h (25 mph)
Lock-uo OFF ON Above approx. 40 km/h (25 mph) Lock-up ON ON ON
OD Lock-up OFF ON ON OD Lock-uo ON ON ON ON
1st ON ON
S 2nd ON ON ON S
3rd Below approx. 40 km/h (25 mph) 3rd Above approx. 40 km/h (25 mph) ON
1st ON ON
L 2nd Below approx. 110 km/h (68 mph) ON ON 2nd Above approx. 110 km/h (68 moh) ON
2nd ON ON ON
D 3rd Below approx. 40 km/h (25 moh) 3rd Above approx. 40 km/h (25 moh) ON
2nd ON ON
HOLD S 3rd Below approx. 40 km/h (25 mph) 3rd Above approx. 40 km/h (25 mph) ON
1st ON
L 2nd Below approx. 110 km/h (68 mph) ON ON 2nd Above approx. 110 km/h (68 mph) ON
7B—26

TROUBLESHOOTING (G4A-EL) 7B
STEP 4 (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
79G07C-084
7B-27

7B TROUBLESHOOTING (G4A-EL)
Procedure
86U07B-034
1. Block the wheels and apply the parking brake.
2. Connect a tachometer to the engine.
3. Shift the selector lever to R.
4. Firmly depress the foot brake with the left foot, and gently depress the accelerator pedal with the right.
5. When the engine speed no longer increases, quickly read the engine speed and release the ac-
celerator.
Caution
Steps 4 ->• 5 must be done within 5 seconds.
6. Move the selector lever to N and let the engine idle for at least one minute.
Caution
The reason for idling for at least one minute is to cool the ATF and to prevent deterioration
of the fluid.
7B-28

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)
STEP 5 (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 condition of the 1-2, N-R, and N-D
accumulators, forward, and one-way clutches, 2-4 brake band, and low and reverse brake.
Preparation
76G07B-030
Procedure
1. Start the engine and check the idle speed in P range.
Idle speed: 900 ±58 rpm
2. Shift from N range to D range
3. Measure the time it takes from shifting until shock is felt, with 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 following shifts in the same manner.
(1) N D range (Hold mode)
(2) N -» R range
Note
Make three measurements for each test and take the average value.
Specified time lag: N -> D range
N -»• R range
Evaluation
Condition Possible Cause
N D (Economy) shifting
More than specification
Insufficient line pressure Forward clutch slipping One-way clutch 1 slipping One-way clutch 2 slipping N D (Economy) shifting
Less than specification N-D accumulator not operating properly
Excessive line pressure
N-D (Hold) shifting
More than specification
Insufficient line pressure Forward clutch slipping 2-4 brake band slipping One-way clutch 1 slipping N-D (Hold) shifting
Less than specification 1-2 accumulator not operating properly
Excessive line pressure
N R shifting
More than specification
Insufficient line pressure Low and reverse brake slipping Revese clutch slipping N R shifting
Less than specification N-R accumulator not operating properly
Excessive line pressure
86U07B-038
0.5—1.0 second
0.5—1.0 second
7B-30

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