Suzuki Wagon R Manual page 752

STEP
6 While ignition switch ON, check voltage between
terminal "B14" and "A25" of disconnected harness
side TCM coupler.
Is it 10 – 14 V at "L" range and 0 V at other range?
7 Check shift switch referring in this section.
Is it OK?
ACTION
AUTOMATIC TRANSMISSION (4 A / T) 7B-41
YES
Intermittent trouble or
faulty TCM.
Check for intermittent
trouble referring to
"Intermittent troubles"
in Section 0B.
Shift switch wire
shorted.
If wire harnesses are
OK, substitute a
known-good TCM and
recheck.
NO
Go to Step 7.
Replace shift switch.