Suzuki Wagon R Manual page 743

7B-32 AUTOMATIC TRANSMISSION (4 A / T)
DTC 21 – SHIFT SOLENOID NO.1
23 – SHIFT SOLENOID NO.2
25 – LOCK-UP SOLENOID
(SHIFT SOLENOID OUTPUT VOLTAGE TOO HIGH EVEN THOUGH
TCM ORDERS SHIFT SOLENOID TO TURN OFF)
STEP
1 1) Turn ignition switch OFF and disconnect
shift solenoid coupler.
2) Measure the resistance between each
solenoid terminal of the solenoid coupler
and transmission ground.
(See chart and figure below.)
Is it about 12 Ω?
2 1) Connect shift solenoid coupler then
disconnect TCM couplers.
2) Measure the resistance between each
solenoid terminal of the disconnected
harness side TCM coupler and body
ground. (See chart and figure below.)
Is it about 12 Ω?
3 Turn ignition switch ON then measure voltage
between terminal "A4", "A17" or "A18" of
disconnected harness side TCM coupler and
body ground.
Is it about 0 V?
Solenoid
Shift solenoid No.1
Shift solenoid No.2
Lock-up solenoid
ACTION
Terminal Number
YES
Go to Step 2.
Go to Step 3.
Poor connection at terminal "A4",
"A17" or "A18"of TCM.
If all the above are in good
condition, the cause can be a
"temporary malfunction" of the
TCM.
A4
A17
A18
1. Shift solenoid No.1
2. Shift solenoid No.2
3. Lock-up solenoid
4. Solenoid coupler
5. TCM coupler
(viewed from harness side)
NO
D Broken solenoid
lead wire.
D Malfunction of
solenoid valve.
Broken "Br", "B/R"
or "B/O" wire or
poor connection of
solenoid coupler.
"Br", "B/R" or
"B/O" wire or
solenoid lead wire
shorted to power
source circuit.
Lead Wire Color
(between TCM and
solenoid coupler)
B/R
B/O
Br