• HO2S HEATER TROUBLESHOOTING
DTC 41-2: Abnormal HO2S heater
1) Symptom reproduction test
a. Turn the combination switch OFF. Disconnect the
HO2S 4P connector
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b. Clear the DTC (P. 5-12).
• Continue the procedure when the DTC does not
clear.
c. Start the engine and let it run at 3,000 min
for 5 minutes or more under no load.
d. Check the DTC using the HDS (Dr. H or pocket
tester).
Does the DTC 41-2 appear?
YES - Go to "2) HO2S heater inspection."
NO - Temporary failure (Disappears.)
2) HO2S heater inspection
a. Turn the combination switch OFF and disconnect
the HO2S 4P connector
b. Measure the resistance between the HO2S side
No.3 (White) terminal and the No.4 (White) terminal
of the HO2S 4P connector
HO2S 4P CONNECTOR HO2S SIDE
18
O2HT (White)
VIEWED FROM THE TERMINAL SIDE
5-35
once and connect it again.
-1
(rpm)
.
18
.
18
(White)
430
Is the measurement within 10 - 40 ?
YES - Go to "3) HO2S heater power line open-
circuit inspection."
NO - Replace the HO2S with a new one and
recheck.
3) HO2S heater power line open-circuit inspection
• Turn the combination switch ON. Measure the
voltage between the HO2S 4P connector
wire harness side No.4 (Yellow/Red) terminal and
the engine ground.
HO2S 4P CONNECTOR
MAIN WIRE HARNESS SIDE
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(Yellow/Red)
VIEWED FROM THE TERMINAL SIDE
Is there the battery voltage?
YES - Go to "4) HO2S heater line short-circuit
inspection."
NO - Check the No.5 fuse and the main relay (P.
18-17, 18). If there is no problem, replace the
main wire harness.
main
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