Knock Sensor 2 Circuit Low Input (Bank 2)
The powertrain control module has detected a low voltage signal from knock sensor 2 on bank 2.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The engine computer isn't getting the right signal from the knock sensor on one side of the engine, which helps it prevent knocking or pinging while running.
What the computer is actually seeing
The PCM expects to see a voltage that fluctuates based on engine vibrations. When the knock sensor is working, it sends a voltage signal between 0.2V to 4.5V depending on the detected knocking. If this voltage drops below 0.2V, it triggers the code.
What a healthy reading looks like
Normal operational voltage from the knock sensor should range between 0.2V to 4.5V.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Inspect the wiring and connectors to Knock Sensor 2 on Bank 2 for damage or corrosion. Decision Point: Are they intact? If no, repair as needed and retest.
- 22. Measure the voltage at the knock sensor's connector with the engine running. Use a multimeter. Decision Point: Is the voltage between 0.2V and 4.5V? If no, the sensor may be faulty.
- 33. If the voltage is out of range, swap the knock sensor with the one from Bank 1 (if applicable) and retest. Decision Point: Does the code change to Bank 1? If yes, replace the knock sensor. If no, check wiring to the PCM.
- 44. If all sensors and wiring are good, check the PCM for codes or faults. Consider reprogramming or replacing as a last resort.
Common causes
- Faulty knock sensor
- Wiring issues between the sensor and PCM
- Poor engine ground
- Faulty PCM
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's drivable but can lead to performance issues, so fix it soon.
Will this problem return after fixing?
If the cause is resolved (like a bad sensor or wiring), it shouldn't return.
Why does this code pair with P0331?
P0331 is related to the first knock sensor; issues often affect multiple sensors.
Working a real vehicle right now?
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