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Check engine light is too sensitive to knock output
Posted: Sat Apr 01, 2017 5:40 pm
by forhome
I have set the check engine light output when knocking is detected. It has been coming on even the knock sensor value doesn't exceed the engine noise level. is there anyway to adjust the sensitivity on the light output. the engine was not knocking according to the datalog. Thanks.
Re: Check engine light is too sensitive to knock output
Posted: Sat Apr 01, 2017 6:38 pm
by roquete
Are you shure the check engine is just reporting knock?
You seem to have at that position some lambda trouble.
Also you can check with "check error code" log parameter.
Re: Check engine light is too sensitive to knock output
Posted: Sat Apr 01, 2017 10:46 pm
by forhome
Here is a graph when the check engine light came on. I thought it was knock at first but the knock sensor input is saying otherwise. I am still working on the ve map that's why the lambda is off.
Re: Check engine light is too sensitive to knock output
Posted: Sat Apr 01, 2017 10:57 pm
by roquete
You are right, it should't throw knock code with that sensor level, either is a bug or some spike of voltage not shown on log.
Are you using shielded wire for knock sensor?
Also try to upgrade to latest version.
Re: Check engine light is too sensitive to knock output
Posted: Sun Apr 02, 2017 4:58 pm
by forhome
I am using a shielded wire for the knock sensor as instructed in the manual. I will try dialing my timing back at that area from 15 to 12 to see if it helps.
Re: Check engine light is too sensitive to knock output
Posted: Mon Apr 03, 2017 5:43 pm
by forhome
It turns out that the check engine light will trigger whenever there's voltage spike regardless of the voltage or the engine noise threshold. Can someone tell me what's a real pinging/knocking in voltage should look like? I am picking up voltage spike around 1.2v that would trigger the check engine light. Thanks.
Re: Check engine light is too sensitive to knock output
Posted: Mon Apr 03, 2017 6:01 pm
by roquete
If its just a voltage spike there is nothing you can do on the ecu, you have to check wiring, ground signals and the knock sensor itself.
Re: Check engine light is too sensitive to knock output
Posted: Tue Apr 04, 2017 8:35 pm
by forhome
Thanks for the reply. I have checked my wiring yesterday to verify everything wired up correctly. Everything is wired up as described in the manual with signal going into knock input, ground going into sensor ground pin at the ecu and everything has been shielded at grounded at one end. Maybe my sensor parameter has been configured incorrectly? My knock frequency is set at 6.64khz for a 86mm bore 4 cylinder engine, the Gain is set at 0.2 and the integrator is set at 240uSec.
Re: Check engine light is too sensitive to knock output
Posted: Wed Apr 05, 2017 9:32 pm
by forhome
It turns out that adjusting the gain will change the check engine light sensitive and using the 2nd harmonic on the frequency help filter out a lot of engine noises. It now just triggers the engine check light when at wot low rpm in 5th which I would say it's legitimate. Hopefully it will help others in the same situation.