Toyota Camry Knock Sensor Problem The top of the radiator on my 1993 3.0 lt Toyota Camry V6, 3VZ FE engine split some months back and it overheated. I have since sorted out the head gaskets and it seems to be running okay. However the check engine light comes on once the engine warms up. Previously this light was coming on soon after the engine overheated, but I thought that it would go away once the repairs had been done. When checking the fault code it comes up that there is a fault with the ?right bank knock control system in ECM? (code 55). Due to the difficult access to this sensor, under the inlet manifold, is there a good way of testing this sensor without pulling the manifold off. Should I assume maybe that there is an actual problem i.e. incorrect cam timing or something else of that nature?

SOURCE: Toyota Camry Knock Sensor Problem

Hello. You have posted an excellent question.

The code 55 you are getting, in Toyota terms, as as follows:

"No number one knock sensor signal to the ECU fo four crank revulutions under these 2 conditions: Coolant temperature 140 degrees F or more; Engine speed between 1600 and 5200 RPM."

This indicates a failed (or a loose) knock sensor on the Right Bank of the engine. Since the knock sensor is basically a piezo-electric crystal, not continuity test can be performed with the intake manifold installed.

You can check the continuity form the Knock Sensor wires to the ECM, but, this may not prove useful to you.

Unfortunately, you are going to have to pull the intake, and check the knock sensor wiring integrity. If the connector is good, and the sensor is tight, I would suggest replacing the sensor. Actually, if you were in my shop, I would suggest replacing them both, as the whole intake will have to come off if the other sensor fails. Better to replace them both at once, than to pull the intake again.

We here at FixYa hope that this helps you out, and saves you some future reoair dollars. Thanks for choosing FixYa for advice.