1987 MAZDA 626 Workshop Manual

TROUBLESHOOTING (G4A-HL) 7B
Evaluation
Condition Possible Cause
No 1-2 shift
Insufficient governor pressure
No 1-2 shift
Stuck 1 range control valve
No 1-2 shift Stuck 1-2 shift control valve No 1-2 shift
Stuck 1-2 shift valve
No 1-2 shift
No check ball (rubber ball)
No 2-3 shift
Insufficient governor pressure
No 2-3 shift
Stuck 2 range control valve
No 2-3 shift Stuck servo control valve No 2-3 shift
Stuck 2-3 shift valve
No 2-3 shift
No check ball (rubber ball)
No 3-OD shift
Insufficient governor pressure
No 3-OD shift
Excessive throttle pressure
No 3-OD shift Stuck OD release valve No 3-OD shift Stuck needle valve of the OD release solenoid valve No 3-OD shift
Stuck 3-4 shift valve
No 3-OD shift
No check ball (rubber ball)
No. Lock-up (Electric circuit is OK)
Insufficient governor pressure
No. Lock-up (Electric circuit is OK)
Stuck OD release valve
Stuck needle valve of the OD release solenoid valve No. Lock-up (Electric circuit is OK)
Stuck OD lock-up valve
No. Lock-up (Electric circuit is OK)
Stuck lock-up control valve
Shift occurred in 2 range Stuck 1-2 control valve Shift occurred in 2 range Stuck 2 range control valve
No kick-down Stuck throttle valve No kick-down Stuck kick-down valve
Incorrect shift point In D and 1 range
Excessive or insufficient governor pressure
Incorrect shift point In D and 1 range Excessive or insufficient throttle pressure Incorrect shift point In D and 1 range
Excessive or insufficient line pressure Incorrect shift point
In 1 range Stuck 1 range control valve
No engine braking effect
Stuck coasting bypass valve
No engine braking effect Fluid leakage from 2-3 accumulator seal rings No engine braking effect
No check ball (rubber ball)
Shift shock or slippage
In 1-2 and/or 3-OD shift
Fluid leakage from 1-2 accumulator seal rings
Shift shock or slippage
In 1-2 and/or 3-OD shift No check ball (rubber ball) or leakage
Shift shock or slippage
In 1-2 and/or 3-OD shift
No one-way check orifice or leakage
Shift shock or slippage In 2-3 shift
Fluid leakage from 2-3 accumulator seal ring
Shift shock or slippage In 2-3 shift
Stuck bypass valve
Shift shock or slippage In 2-3 shift
Stuck 2-3 timing valve
Shift shock or slippage In 2-3 shift Stuck coast bypass valve Shift shock or slippage In 2-3 shift
Stuck servo control valve Shift shock or slippage In 2-3 shift
No one-way check orifice or leakage
Shift shock or slippage In 2-3 shift
No check ball (rubber ball) or leakage
Shift shock or slippage
In 3-2 shift
Fluid leakage from 1-2 accumulator seal ring
Shift shock or slippage
In 3-2 shift No check ball (rubber ball) or leakage
Shift shock or slippage
In 3-2 shift Stuck 3-2 timing valve
Shift shock or slippage
In 3-2 shift
Stuck 3-2 capacity valve
83U07B-046
7B—57

7B TROUBLESHOOTING (G4A-HL)
Line Pressure Test
Preparation
1. Connect the SST to the line pressure output point
(square head plug L).
2. Connect a tachometer to the engine.
3. Perform the preparation procedure shown in STEP
3 (STALL TEST).
STEP 6 (OIL PRESSURE TEST)
This step checks line, throttle, and governor pressures to check the operation of hydraulic compo-
nents and for oil leakage.
83U07B-047
Procedure
76G07B-062
1. Start the engine and check that the idle speed is 900 rpm.
2. Shift the selector lever to D range.
3. Read the line pressure at idle.
4. Depress the brake pedal firmly with the left foot and gradually depress the accelerator pedal with
the right foot.
5. Read the line pressure as soon as the engine speed becomes constant, then release the accelera-
tor pedal.
Caution
Steps 4 to 5 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—58

TROUBLESHOOTING (G4A-HL) 7B
Specified Line pressure:
Condition Line pressure kPa (kg/cm2, psi)
Range DSL R
When idling 350-490 (3.6-5.0, 51-71) 600-830 (6.1-8.5, 87-121)
At stall speed 980-1230 (10.0—12.5, 142—178) 1470-1960 (15.0-20.0, 213-284)
76G07B-063
Evaluation
Condition Possible Cause
Below specification
In all ranges
Worn oil pump
Below specification
In all ranges
Fluid leakage from the oil pump, control valve body
and/or transaxle case
Below specification
In all ranges Stuck pressure regulator valve
Below specification
In all ranges
Stuck throttle valve
Below specification
In all ranges
Stuck pressure modulator valve
Below specification
In D, 2 and 1 range
Fluid leakage from the forward clutch hydraulic circuit
Below specification
In D, 2 and 1 range Fluid leakage from the governor valve hydraulic circuit
Below specification
In D, 2 and 1 range
Fluid leakage from the N-R accumulator seal rings
Below specification In D and 1 range Fluid leakage from the 2-3 accumulator seal rings Below specification In D and 1 range Fluid leakage from the 1-2 accumulator seal rings Below specification
In D and R range Fluid leakage from the N-D accumulator seal rings
Below specification
In 2 and 1 range Fluid leakage from the coasting clutch hydraulic circuit
Below specification
In 2 and 1 range Stuck throttle backup valve
Below specification
In R and 1 range Fluid leakage from the low and reverse brake hydraulic
circuit
Below specification
In 2 range only Fluid leakage from 2-4 brake servo hydraulic circuit
Below specification
In 1 range only Stuck low reducing valve
Below specification
In R range only Fluid leakage from reverse clutch hydraulic circuit
Excessive line pressure
Stuck throttle valve
Excessive line pressure Stuck throttle modulator valve Excessive line pressure Stuck pressure regulator valve Excessive line pressure
Stuck throttle backup valve
76G07B-216
7B—59

7B TROUBLESHOOTING (G4A-HL)
Throttle Pressure Test
Preparation
1. Connect the SST to the throttle pressure output
point (Square head plug T).
2. Connect a tachometer to the engine.
3. Perform the preparation procedure shown in STEP
3 (STALL TEST).
83U07B-052
Procedure
76G07B-064
1. Start the engine and check that the idle speed is 900 _5o rpm.
2. Shift the selector to D range.
3. Read the throttle pressure at idle.
4. Depress the brake pedal firmly with the left foot and gradually depress the accelerator pedal with
the right foot.
5. Read the throttle pressure as soon as the engine speed becomes constant, then release the ac-
celerator pedal.
Caution
Steps 4 to 5 must be performed within 5 seconds.
7B-60

TROUBLESHOOTING (G4A-HL) 7B
Specified throttle pressure:
Condition Throttle pressure kPa (kg/cm2, psi)
When idling 83-113 (0.85-1.15, 12-16)
At stall speed 540-610 (5.5-6.2, 78-88)
Evaluation
Condition Possible Cause
Stuck throttle valve
Not within specification Stuck pressure regulator valve
Improper adjustment of throttle cable
7B-61

7B TROUBLESHOOTING (G4A-HL)
Governor Pressure Test
Preparation
1. Connect the SST to the governor pressure output
point.
2. Place the pressure gauge inside the vehicle.
3. Warm up ATF and check ATF level.
83U07B-054
Procedure
76G07B-065
1. Drive the vehicle in D range.
2. Read the governor pressure at the speeds listed in the table below.
Specified governor pressure:
Vehicle Speed km/h (mph) Governor Pressure kPa (kg/cm2, psi) Vehicle Speed km/h (mph) FE engine F8 engine
30 (19) 79-114 (0.81-1.16, 12-16) 82-117 (0.84-1.19, 12-17)
55 (34) 146-190 (1.49-1.94, 21-28) 157-201 (1.60-2.05, 23-29)
85 (53) 276-339 (2.81-3.46, 40-49) 302-366 (3.08-3.73, 44-53)
Evaluation
Condition Possible Cause
Not within specification
Fluid leakage from the line pressure hydraulic circuit
Not within specification Fluid leakage from the governor pressure hydraulic circuit Not within specification
Defective or stuck governor valve
7B-62