Dtc P0031 / P0032: Ho2S Heater Control Circuit Low / High (Sensor-1) - Suzuki GRAND VITARA Owner's Manual

1A-65 Engine General Information and Diagnosis:
DTC Troubleshooting
NOTE
Before this trouble shooting is performed, read the precautions for DTC troubleshooting referring to
"Precautions For DTC Troubleshooting: ".
Step
1 Was "Engine and Emission Control System Check"
performed?
2 DTC check
Is there any DTC(s) other than P0030?
3 Sensor circuit check
1) Disconnect connectors from A/F sensor and ECM with
ignition switch turned OFF.
2) Check for proper connection to A/F sensor terminals and
ECM terminals.
3) If wire and connection are OK, measure each wire
resistance of A/F sensor circuit (sensor and heater)
between A/F sensor connector and ECM connector.
Is each measured wire resistance lower than 1
4 Sensor circuit insulation check
1) Measure resistance between wire and wire at sensor
circuit terminals of A/F sensor connector (no continuity
check).
Is measured resistance infinity?

DTC P0031 / P0032: HO2S Heater Control Circuit Low / High (Sensor-1)

Wiring Diagram
Refer to "DTC P0030: HO2S Heater Control Circuit (Sensor-1): ".
A/F Sensor Description
Refer to "A/F Sensor Description: ".
DTC Detecting Condition and Trouble Area
DTC detecting condition
P0031:
Heater control circuit voltage of A/F sensor is lower than
specification for more than specified time continuously even
though control duty ratio of A/F sensor heater is less than 90%
with engine running. (Heater control duty pulse is not detected
in its circuit of ECM)
(2 driving cycle detection logic)
P0032:
Heater control circuit voltage of A/F sensor is higher than
specification for more than specified time continuously even
though control duty ratio of A/F sensor heater is more than 10%
with engine running. (Heater control duty pulse is not detected
in its circuit of ECM)
(2 driving cycle detection logic)
Action
Ω
?
Yes
Go to Step 2.
Go to applicable DTC
diag. flow.
Go to Step 4.
Substitute a known
good A/F sensor and
recheck.
Trouble area
• A/F sensor heater circuit
• A/F sensor heater
• ECM
No
Go to "Engine and
Emission Control
System Check: ".
Go to Step 3.
Repair or replace
defective wire circuit.
Repair or replace
defective circuit.
S5JB0A1104015