Mitsubishi MOTORS Space Runner 1998, Workshop Manual

Page: 479 / 1164

AUTOMATIC TRANSMISSION -
Troubleshooting
23-19
Code No. 42 2nd gear ratio does not meet the specification Probable cause
If the output from the output shaft speed sensor multiplied by the 2nd gear ratio
is not the same as the output from the input shaft speed sensor after shifting to
2nd gear has been completed, diagnosis code No. 42 is output. If diagnosis code
No. 42 is output four times, the transmission is locked into 3rd gear as a fail-safe
measure, and the N range lamp flashes at a frequency of 1 Hz.
D Malfunction of the input shaft speed sensor
D Malfunction of the output shaft speed sensor
D Malfunction of the underdrive clutch retainer
D Malfunction of the transfer drive gear or driven gear
D Malfunction of the second brake system
D Malfunction of the underdrive clutch system
D Noise generated
L
: Refer to the Transmission Workshop Manual.
MUT-
II
Self-Diag code
Is the diagnosis code No. 22 output?
Yes
Code No. 22 Input shaft speed sensor system check
(Refer to P.23-14.)
No
MUT-
II
Self-Diag code
Is the diagnosis code No. 23 output?
Yes
Code No. 23 Output shaft speed sensor system check
(Refer to P.23-15.)
No
Measure output waveform from the input shaft speed sensor. (using
an oscilloscope)
D Connect the connector A-90 and measure voltage between
31 and 43 at the A/T-ECU.
D Engine: 2,000 r/min (approx. 50 km/h)
D Selector lever position: 3
(Voltage)
OK:
A waveform such as theone shown on P.23-43 (Inspection
Procedure Using an Oscilloscope) is output (flashing be-
tween 0 ¨ 5V) and there is no noise appearing in
the waveform.
NG
Replace the input shaft speed sensor.
Check the trouble symptoms.
NG
A/T overhaul L
D Replace the underdrive clutch retainer.
Check the trouble symptoms.
NG
Eliminate the cause of the noise.
OK
Measure output waveform from the output shaft speed sensor.
(using an oscilloscope)
D Connect the connector A-82 and measure voltage between
32 and 43 at the A/T-ECU.
D Engine: 2,000 r/min (approx. 50 km/h)
D Selector lever position: 3
(Voltage)
OK:
A waveform such as theone shown on P.23-43 (Inspection
Procedure Using an Oscilloscope) is output (flashing be-
tween 0 ¨ 5V) and there is no noise appearing in
the waveform.
NG
Replace the output shaft speed sensor.
Check the trouble symptoms.
NG
A/T overhaul L
D Replace the transfer drive gear and driven gear.
Check the trouble symptoms.
NG
Eliminate the cause of the noise.
OK
A/T overhaul L
D Underdrive clutch system check
(No. 41, No. 43, or no diagnosis code is output).
D Second brake system check
(No. 44 or no diagnosis code is output).