1A-73 Engine General Information and Diagnosis:
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
1) With ignition switch turned OFF, connect scan tool to DLC.
2) Turn ON ignition switch and clear DTC.
3) Start engine and warm up to normal operating temperature.
4) Run engine at idle speed for 1 min. or more.
5) Check DTC and pending DTC.
DTC Troubleshooting
NOTE
Before this trouble shooting is performed, read the precautions for DTC troubleshooting referring to
“Precautions for DTC Troubleshooting”.
DTC detecting condition
Trouble area
DTC P0057 HO2S Heater Control Circuit Low (Sensor-2, Bank-2):
Circuit current of HO2S (bank-2) heater is lower than specification
(0.16 – 0.28 A depending on battery voltage) for more than 1 sec.
continuously while control duty of HO2S sensor heater is ON with
engine running.
(2 driving cycle detection logic)
DTC P0058 HO2S Heater Control Circuit High (Sensor-2, Bank-2):
Circuit current of HO2S sensor (bank-2) heater is higher than 5 A at
ON duty pulse or 0.2 A at OFF duty pulse for more than 1 sec.
continuously while control duty of HO2S sensor heater is ON with
engine running.
(2 driving cycle detection logic)
• HO2S heater circuit
• HO2S
• ECM
Step
Action
Yes
No
1
Was “Engine and Emission Control System Check”
performed?
Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2
A/F sensor DTC check
Are there DTC P0031 and/or P0051?
Go to applicable DTC
flow referring to “DTC
P0031 / P0032: HO2S
Heater Control Circuit
Low / High (Sensor-1,
Bank-1)” and/or “DTC
P0051 / P0052: HO2S
Heater Control Circuit
Low / High (Sensor-1,
Bank-2)”.
Go to Step 3.
3
HO2S heater relay and its circuit check
1) Disconnect connector from HO2S (bank-2) with ignition
switch turned OFF.
2) Check for proper terminal connection to HO2S (bank-2)
connector.
3) If connections are OK, check that HO2S (bank-2) heater
control circuit is as follows.
• Circuit voltage between “Power supply circuit of HO2S
(bank-2) heater” and vehicle body ground is battery
voltage with ignition switch turned ON.
Is it in good condition?
Go to Step 4.
Repair or replace
defective wiring
harness.