Technical Description of OBD-II Trouble Code
High Input in Knock Sensor 2 Circuit (Bank 2)
What does that signify?
This diagnostic trouble code (DTC) is a generic powertrain code that is applicable to vehicles equipped with OBD-II. Although it is a generic code, the specific repair steps may vary depending on the make and model of the vehicle.
Knock sensors are utilized to detect engine pre-detonation, also known as engine knock or ping.
The knock sensor (KS) is typically a two-wire sensor. The sensor receives a 5-volt reference and sends a signal back to the PCM (powertrain control module). The sensor signal wire informs the PCM about the occurrence and severity of a knock. The PCM will adjust the spark timing to prevent pre-detonation. Most PCMs can learn spark knock trends during normal engine operation.
A P0333 code is a generic DTC that applies to all vehicle makes. It indicates a high output voltage from the knock sensor. In many cases, this means the voltage is above 4.5V, but the specific value depends on the make and model of the vehicle. This code refers to the sensor on bank #2, which is the side of the engine that does not contain cylinder #1.
Symptoms
The symptoms of a P0333 DTC may include:
Causes
Possible causes of a P0333 code include:
Possible Solutions
If you can hear engine knock (detonation), first address the mechanical problem and then retest. Ensure that the correct octane fuel is being used (some engines require premium fuel, so check the owner’s manual). Apart from that, for this code, the problem is most likely either with the knock sensor itself or with the wiring and connectors between the sensor and the PCM.
For DIY vehicle owners, the recommended next steps are to measure the resistance between the two knock sensor wire terminals where they connect to the PCM. Also, check the voltage of the same terminals. Compare these values to the manufacturer’s specifications. Additionally, inspect all wiring and connectors that lead from the knock sensor to the PCM. Furthermore, use a Digital Volt Ohm Meter (DVOM) to measure the resistance of the knock sensor itself and compare it to the vehicle manufacturer’s specification. If the knock sensor resistance value is out of spec, it needs to be replaced.
Other knock sensor DTCs include P0324, P0325, P0326, P0327, P0329, P0330, P0331, P0332, P0333, P0334
