AUTOMATIC TRANSMISSION (4 A/T) 7B-17
Trouble Diagnosis Table
Trouble diagnosis table-1
Electrical Repair
NOTE:
For the inspection of throttle position sensor, refer to “TP SENSOR” in Section 6E.
Condition Possible Cause Correction
No up-shift
1st → 2nd
2nd → 3rd
• Output shaft speed sensor or its circuit faulty Inspect output shaft speed sen-
sor.
• Shift solenoid -D (No.4) (1st → 2nd), -A
(No.1) (1st → 3rd), -E (No.5) (2nd → 3rd),
and/or its circuit faulty
Repair or replace.
• Throttle position sensor or its circuit faulty Inspect TP sensor.
• TCM faulty Replace TCM.
3rd → 4th • Output shaft speed sensor or its circuit faulty Inspect output shaft speed sen-
sor.
• Shift solenoid -B (No.2), -C (No.3) or its cir-
cuit faulty
Repair or replace.
• O/D CUT switch circuit faulty Refer to “O/D OFF SWITCH” in
this section and/or inspect its cir-
cuit.
• Throttle position sensor or its circuit faulty Inspect TP sensor.
• TCM faulty Replace TCM.
No down-shift
4th → 3rd
3rd → 2nd
2nd →1st
• Shift solenoid -C (No.3) (4th → 3rd), -D
(No.4) (2nd → 1st), -A (No.1) (3rd → 2nd), -B
(No.2) (4th → 3rd), -E (No.5) (3rd → 2nd) or
its circuit faulty
Repair or replace.
• Throttle position sensor or its circuit faulty Inspect TP sensor.
•TCM fault Replace TCM.
Shift point too high or
too low
• Throttle position sensor, output shaft speed
sensor or its circuit faulty
Inspect TP sensor and/or output
shaft speed sensor.
Vehicle does not move • Shift solenoid -A (No.1), -C (No.3), -D (No.4)
or its circuit faulty
Repair or replace.
Excessive slip • Shift solenoid -A (No.1) to -E (No.5) or its cir-
cuit faulty
Repair or replace.
Excessive shock at
N → D or N → R
• Shift solenoid -A (No.1), -D (No.4), -E (No.5)
or its circuit faulty
Repair or replace.
• ISC circuit Inspect ISC circuit.
No lock-up or
No lock-up OFF
• TCC (lock-up) solenoid valve or its circuit
faulty
Repair or replace.
• Throttle position sensor or its circuit faulty Refer to “THROTTLE POSITION
SENSOR” in Section 6E.
• Input shaft speed and/or output shaft speed
sensor or its circuit faulty.
Refer to “ECT SENSOR” in Sec-
tion 6E.
• Abnormal engine rev. signal or its circuit. Repair or replace.
• ECM faulty Inspect ECM.