code 55

[chap_oner]

hi i have a 92 es 300 im getting a code 55 which is a knock sensor 2. i tried to do everything but i still cant get it to go away. is there any way to bi bass the knock sensors. like shorting them out or grounding them . or if there is someone that has had the same experience please reply and fill me in with some helpfull onfo
thanks

[Brian R.]

Welcome to the AF!

What have you done to try and fix the problem?

If you haven't, replace the wires to the sensors. That is usually the problem. Check the connection between the sensors and the leads, as well as the other end of the leads for good connection.

While you're at it, check for continuity between the sensor contact and the body. There should be no continuity.

[chap_oner]

Originally Posted by Brian R.

Welcome to the AF!

What have you done to try and fix the problem?

If you haven't, replace the wires to the sensors. That is usually the problem. Check the connection between the sensors and the leads, as well as the other end of the leads for good connection.

While you're at it, check for continuity between the sensor contact and the body. There should be no continuity.

at first i thought it would be the ks so i replaced it. 5 min later BAM!!! the cel comes back on. i took off glove box and unplugged 2nd connector on ecu and measured resistance between knk1 and ground and same with knk2 there was no continuity on knk2. so i unplugged the connector that leads under the intale to see if there is resistance again there was none on one of the wires. i have the diagrams to the ks, and it seems like they are grounder somewhere in the harness to the right of intake manifold. i was wondering what it is the ecu reads, is it voltage, resistance. and if so what are the normal values. i wanted to see if i can just solder a resister straight into the ecu terminal knk1 and knk2.

[Brian R.]

The sensors send a pulse of low voltage when the piezoelectric crystal is twinged by a knock at the normal frequency.

See page 32 of http://www.autoshop101.com/forms/h24.pdf

[chap_oner]

WOW so there is no way to replicate that wave form in a manner in which the comp. reads an ok signal huh??? thanks for the info, again. if you know anything else besides changing wiring harness. fill me in dude. thanks

[Brian R.]

No I think not. The ECM constantly advances the timing until ping is detected, or a set value is reached, and then retards it if ping is detected. Over and over. Without feedback, you will have problems associated with retarded timing.

[chap_oner]

thanks for all your help. ill keep you posted once i find out what the prob. was. thanks