2001 accord EX 2.3l ULEV Originally threw P0325 and found old sensor fell apart and plastic was broken free from metal housing. Changed sensor with one from Ebay and light came right on. Checked wiring per service manual and is good. Ordered another sensor off of Amazon. Still throwing p0325, Now I don't want to buy a $130 sensor from Honda because I do not think it is the sensor at this point. could it be ECU? Should I run a new wire to ensure everything is OK.

What should reading be from sensor when car is running? Do you need an oscillascope to read?

Car runs fine but will need to fix so I can pass emissions.

 

P0325 indicates an electrical fault (short or open) in the wiring from sensor to ECM. Are you absolutely sure there is no fault in sensor (seems unlikely) and wiring (Have you checked wiring from ECM connector to knock sensor?)?

If you're convinced wiring and sensor are good, the ECM fault is likely.

good luck

 

Checked wiring to ECM from sensor for short and open per factory workshop manual, with no faults found. find it hard to believe ECM is bad because I originally found sensor plastic had separated from metal base. anything is possible, but what sort of signal does sensor give while car is running, ac, doc, can it be checked with multimeter? Could connection be bad?

what is torque value for sensor. Nothing listed in manual.

 

As previously stated; generally, the code can be due to the sensor, wiring, wiring connections, or ECM/PCM.

The knock sensor has a piezo ceramic element that creates its own voltage signal/pulse in response to vibrations which may be caused by detonation. The ECM/PCM will set the trouble code if the knock sensor voltage pulses are not appropriate.

Part of the wiring for the knock sensor going to the ECM/PCM is shielded with braided wire. This is to shield the knock sensor voltage signal from interference from noise created from the ignition system. The shielding is braided around the outside of the signal wire; the braided wire is connected to a Brn/Blk wire, which connects to a Blk wire, which eventually leads to ground location G101. The shielding picks up noise like an antenna and channel it to ground instead of to the ECM/PCM as a noisy signal. Visually check the shielded Red/Blu wire leading to the ECM/PCM for any signs of damaged. In addition, there is a 14P gray junction connector above the knock sensor, check that the wiring and connector is okay there (clean, wiring and connector secure, etc.); as the Brn/Blk wires and Blk wires there provide the ground path for the braided shield wire leading to ground G101. Examine the knock sensor harness connector, etc.