4-60 FI SYSTEM DIAGNOSIS
“C23” (P1651-H/L) TO SENSOR CIRCUIT MALFUNCTION
INSPECTION
Step 1 (When indicating C23:)
1) Turn the ignition switch to OFF.
2) Lift and support the fuel tank. (
5-3)
3) Check the TO sensor coupler for loose or poor contacts.
If OK, then measure the TO sensor resistance.
4) Disconnect the TO sensor coupler.
5) Measure the resistance between terminal
A
and terminal
C
.
TO sensor resistance: 16.5 – 22.3 k
Ω
(Terminal
A
– Terminal
C
)
09900-25008: Multi-circuit tester set
Tester knob indication: Resistance (
Ω
)
Is the resistance OK?
DETECTED CONDITION
POSSIBLE CAUSE
C23
The sensor voltage should be the follow-
ing for 2 sec. and more, after ignition
switch is turned ON.
0.2 V
Sensor voltage < 4.8 V
• TO sensor circuit open or short
• TO sensor malfunction
• ECM malfunction
P1651
H
Sensor voltage is higher than specified
value.
• TO sensor circuit shorted to VCC or ground circuit
open
• TO sensor circuit open or shorted to ground or
VCC circuit open
L
Sensor voltage is lower than specified
value.
ECM
E2
TOS
R
B/Br
VCC
TO sensor
B
1
YES
Go to Step 2.
NO
Replace the TO sensor with a new one.
1