P0162 OBD2 Code Guide
P0162 is a powertrain diagnostic trouble code. Use this hub to understand the plain meaning, the first checks to run, and which vehicle-specific guides may be more useful before replacing parts.
O2 Sensor Circuit Malfunction (Bank 2, Sensor 3)
Code P0162 indicates that the Powertrain Control Module (PCM) has detected an electrical circuit malfunction in the third oxygen sensor (post-catalytic converter) on Bank 2. Bank 2 refers to the engine side that does not contain cylinder #1. Sensor 3 is typically a downstream sensor, responsible for monitoring the efficiency of the catalytic converter. A "circuit malfunction" means the PCM is not receiving the expected voltage signal or activity from the sensor, or it detects an open or short circuit within the sensor's wiring or the sensor itself. This could be due to a faulty sensor, damaged wiring, a poor connection, or an issue with the sensor's heater circuit.
Code verification standard
P0162 is published with SAE J2012 / ISO 15031-6 code structure plus OBD2 P0162 diagnostic context.
First checks
- - Read all stored and pending codes before clearing anything.
- - Save freeze-frame data so you know speed, load and temperature when the code set.
- - Inspect wiring, connectors, fuses, hoses and obvious leaks tied to the named system.
- - Compare live data against realistic values before buying sensors or modules.
- - Clear the code only after repair and complete a drive cycle to confirm it does not return.
P0162 diagnostic path
- 1Connect an OBD-II scanner to verify the P0162 code and check for any other related codes (e.g., heater circuit codes). Visually inspect the Bank 2 Sensor 3 and its wiring harness for any obvious damage, fraying, burns, or loose connections. Check for exhaust leaks near the sensor, which can affect its readings.
- 2With the engine at operating temperature, use a scan tool to monitor the live data for Bank 2 Sensor 3. Observe its voltage readings. A healthy post-catalytic converter O2 sensor should show a relatively steady voltage, typically between 0.4V and 0.9V, indicating the catalytic converter is functioning. If the voltage is stuck low (near 0V), stuck high (near 1V), or shows no activity, it confirms a circuit issue. Also, check the heater circuit status if available.
- 3Disconnect the Bank 2 Sensor 3 connector. Using a multimeter, test the resistance of the sensor's heater element (usually two white wires). Compare to manufacturer specifications (typically 2-10 ohms). Test for continuity in the sensor's signal and ground wires back to the PCM connector, and check for any shorts to ground or power. Also, verify power and ground supply to the sensor's heater circuit from the vehicle harness side.
- 4With the ignition ON (engine OFF), use a multimeter to check for 12V power supply to the heater circuit wires at the sensor connector (vehicle side). Also, verify a good ground connection for the heater circuit. A lack of power or ground to the heater circuit can cause a "circuit malfunction" code even if the sensor itself is otherwise functional.
- 5If all sensor and wiring tests prove inconclusive, it may be necessary to perform pin-out tests at the PCM connector to verify the signal input from the O2 sensor and the heater circuit control output. This step helps rule out an internal PCM fault, though it's less common for this specific code.
Verify before repair
- - Replace the faulty Bank 2, Sensor 3 oxygen sensor.
- - Repair or replace damaged, corroded, or shorted wiring and connectors leading to Bank 2, Sensor 3.
- - Inspect and replace any blown fuses related to the O2 sensor heater circuit.
- - Repair any exhaust leaks located upstream or directly at the Bank 2, Sensor 3 mounting point.
Vehicle-specific pages to check next
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