P0327: Mechanic solutions that really WORKED!

The P0327 code indicates that the knock sensor on Bank 1 is not producing enough voltage. The knock sensor detects engine knocking (unplanned detonations) and sends signals to the ECU to adjust the engine’s timing. If the sensor’s voltage is too low, it may not detect knocking, leading to possible engine damage.

P0327 quick overview

Meaning	P0327: Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor)
Is it serious?	This code should be addressed promptly as it can lead to engine performance issues and potential engine damage if knocking occurs.
Possible causes	-Faulty knock sensor -Damaged or faulty wiring for the knock sensor -Knock sensor harness open or shorted -Faulty Engine Control Module (ECM) (less common)
How to diagnose?	Scan for Additional Codes: Use an OBD2 scanner to check for additional codes and erase P0327 to see if it returns after driving. Inspect Wiring: Perform a visual inspection of the knock sensor wiring and connectors for damage or corrosion. Test Power/Ground: Use a digital multimeter to ensure the knock sensor is receiving the correct voltage. Check Sensor Resistance: Disconnect the sensor and test its resistance; it should be more than 0.5 ohms. Use Oscilloscope: If resistance and wiring are fine, use an oscilloscope to verify the sensor’s response to engine vibrations.

P0327 Case Study – How mechanics fixed it

I looked into P0327 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

P0327 on Chevrolet Tahoe 1997 5.7L

Customer’s complaint: Check engine light (MIL) is ON
Mechanic’s Fix: Only stored code is P0327, the knock sensor’s resistance is slightly off which is setting the code. Fixed by replacing the knock sensor

p0327 on Mercedes-Benz C36 AMG 1996 3.6L

Customer’s complaint: Check engine light (MIL) is ON
Mechanic’s Fix: Only code stored is P0327, the wiring harness was tested and after confirming it is good, the knock sensor was replaced. However, the car was back shortly with the same code + new code for restricted EGR flow. The EGR ports were cleaned, and codes were deleted. The car came back again with code P0327 only, and the fix was done by repairing the shielding around the knock sensor’s wiring harness (even though the wires were intact).

p0327 on Volkswagen CC luxury 2010 2.0L

Customer’s complaint: Check engine light (MIL) is ON after replacing water pump/timing kit
Mechanic’s Fix: After testing the wires, the low voltage was discovered on the computer-sensor wiring. The sensor was probably damaged due to a previous coolant leak and was fixed by replacing the knock sensor.

p0327 on Saturn SL1 1.9L 2001

Customer’s complaint: Reflash newly installed used ECM, P0327 came soon after that
Mechanic’s Fix: After the wiring/sensor test and unplugging various other sensors like TPS, MAP, EGR, and others, it was still a mystery. The mechanic solved it by finding the old ECM which the customer replaced and finding out that the customer’s new ECM wasn’t the right one for the vehicle by checking the part number. Code is solved by using ECM with the right serial number.

p0327 on 2002 Porsche 911 Carrera 3.6L

Customer’s complaint: Low power, P0327 code stored
Mechanic’s Fix: The fix was easily done by repairing damaged wiring, however, the harder part was accessing the sensor which was hidden under the alternator and water coolant hoses.

p0327 on 1999 Chevrolet Lumina 3.1L

Customer’s complaint: MIL Lamp on
Mechanic’s Fix: Stored code P0327. The mechanic replaced the knock sensor, checked the sensor’s electrical circuit multiple times, and even tried to replace ECM, which all failed to fix the problem. After researching data, he read that this code can be created by shorted cam/crank sensor circuits. The cam sensor had a short, after repairing the wiring the problem is fixed.

p0327 on 2004 Nissan 350Z Track 3.5L

Customer’s complaint: MIL Lamp on, car not starting (P0327)
Mechanic’s Fix: The mechanic reported changing the knock sensor, clearing codes, and returning the fixed car to the customer. However, according to other mechanics, the knock sensor wouldn’t cause a no-start condition, as well as trigger the MIL if it is only code stored.

Knock sensor codes are common in Nissan vehicles and they often point out timing issues, which could be possibly the case here (fault in cam/crank sensors), which is more likely to cause no start or harder starting conditions. I am guessing that this repair didn’t last long.

Additional tips from mechanics

• Remove the ECM fuse for 10 minutes if replacing sensors didn’t work
• Use only OEM sensors
• Don’t forget to tighten the sensor to the exact required torque