O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 2)
The oxygen sensor heater on the exhaust side of your catalytic converter (Bank 2, Sensor 2) isn't working properly, so it can't warm up fast enough to send accurate readings to the engine computer. Think of it like a cold thermometer that gives wrong readings until it warms up.
The ECU monitors the heater circuit resistance and current draw during the first few seconds after engine start. The heater should reach operating temperature within 10-30 seconds, allowing the O2 sensor to produce accurate voltage signals. If resistance is too high or current draw is abnormal, the ECU detects a malfunction.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Heater Circuit Voltage | 12-14V supply with 0.5-2.5A current draw | No voltage, excessive current, or open circuit detected |
| Heater Response Time | Sensor reaches ~0.5V within 10-30 seconds | Sensor remains unresponsive or voltage rises too slowly |
Code P0162 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P0162 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.