jerryp

I have a 1996 300es and I have a PO330 code, I was thinking about jumping to the good sensor. I have found the connector (I think) and I have unpluged it and it has 4 wires on the female end and only two wires on the male end going to the knock sensors. Can you tell me how to make the jumpers and to which pins on the 4 wire plug.

Both P0325 & P0330 are for the absence of a signal from the knock sensors. The knock sensors are a pizo electric crystal, that generate a voltage when mechanically stressed. IE, it picks up vibration, and generates a voltage according to the amount of vibration. Since knocking is just a stronger vibration, it will generate a larger voltage. So with this in mind, you can deduce that there should be a signal any time the engine is running.

So these codes stand for the absence of a signal from one of the sensors. On some cars (such as some of the older chevy v8's), you could test the sensor function by LIGHTLY hitting the block with a hammer, near the sensor, while monitoring the timing. The computer should pick up the hammering and interpret it as knocking, and !Removed! the timing.

Once you have swapped the wires, and determined if the sensor / wire attached to the sensor is bad, you then need to determine if it is worth the hassle to repair it, or just jumper the signal from the good sensor, to both inputs. I know people will have their different opinions, BUT when this problem happens on my car, I assure you that I will install a jumper. Of course some day the other wire/sensor may fail, and then you will need to pull the manifold and repair it.

There is one other thought that I have read about. Some people will just jury rig a bracket on the end of the engine (using one of the engine to trany bolt). And bolt a sensor to this bracket. Since you would assume that any knocking would transmit throughout the entire block, you should still pick up the knocking. I would tend to agree with this logic, but I personally feel that jumping both signals is good enough.