Suzuki sq-416-420-625 Service Manual page 447

TROUBLESHOOTING (DTC P0720)
STEP
1 Was "A/T DIAG. FLOW TABLE" performed?
2 Output speed sensor circuit check:
1) Remove PCM cover.
2) With ignition switch OFF, disconnect PCM
connectors.
3) Check for proper connection to output speed sensor
at C51-1-22 and C51-1-23 terminals for G16/J20
(at C51-1-9 and C51-1-10 terminals for H25).
4) If OK, check resistance of sensor circuit.
Resistance between C51-1-22
and C51-1-23 for G16/J20
(C51-1-9 and C51-1-10 for H25):
Resistance between C51-1-22/
C51-1-23 for G16/J20 (C51-1-9/
C51-1-10 for H25) and ground:
Are check results satisfactory?
3 Output speed sensor check:
1) With ignition switch OFF, disconnect output speed
sensor connector.
2) Check for proper connection to output speed sensor
at each terminals.
3) If OK, then check resistance of output speed sensor.
Are measured values as specified in Step 2?
4 Check visually output speed sensor and sensor rotor
for the followings.
D No damage
D No foreign material attached
D Correct installation
Are they in good condition?
Reference
Oscilloscope waveforms
2 V/Div.
Waveforms at about 25 mph, 40 km / h
ACTION
387 – 473 f at
20 _C, 68 _F
1 Mf or more
Connect oscilloscope between C51-1-23 (+) and C51-1-22 (–) for
G16/J20 (C51-1-10 (+) and C51-1-9 (–) for H25) of PCM connector
connected to PCM and check output speed sensor signal.
5 ms / Div.
AUTOMATIC TRANSMISSION (4 A / T) 7B1-45
YES
Go to Step 2.
Go to Step 4.
"Or" or "W" wire
open or shorted to
ground.
Intermittent trouble
or faulty PCM.
Check for intermittent
referring to
"Intermittent and
Poor Connection" in
Section 0A.
NO
Go to "A/T DIAG.
FLOW TABLE".
Go to Step 3.
Replace output
speed sensor.
Clean, repair or
replace.