PCM/ECM sets DTC P0031 if the PCM/ECM detects that the front HO2S heater control circuit is short to ground.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Electrical Check | 1. Related fuse blown or missing 2. Open or short to ground in power supply or control harness 3. Poor connection or damaged harness 4. Faulty HO2S |
Enable Conditions |
•
No relevant failure
•
10V< Battery voltage <16V
•
3.5%< O2 sensor heater control duty <96.5% | |
Threshold Value |
•
HO2S Heater Output < Lower Threshold | |
Diagnostic Time |
•
10 sec. | |
Mil On Condition |
•
2 Driving Cycles |
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Electrical Check | 1. Related fuse blown or missing 2. Open or short to ground in power circuit 3. Short to ground in control circuit 4. Poor connection or damaged harness 5. Faulty HO2S |
Enable Conditions |
•
10V < Battery voltage < 16V
•
1.5% < Heater power < 98.5%
•
Exhaust gas Temp. > 300°C (572℉) | |
Threshold Value |
•
Short to ground | |
Diagnostic Time |
•
1sec. | |
Mil On Condition |
•
2 Driving Cycles |
