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G4 knock control input specs.


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I am trying to install a third party knock sensor interface to use the built in knock control facility. The ECU is a G4 plug & play for st185 / MR2 turbo rev 2.

The system currently provides a 0-5V analogue 'knock level' output, as per the spec. for the G4. I now find this facility has been withdrawn in the current firmware.

1. - Are there any plans to re-instate this facility, and if so what are the timescales ?

2. - Alternatively, can you provide a detailed specification of what is required for the digital input - e.g. pulse width, data stream etc. The knock sensor interface does have a micro on board which can procuce such a digital signal if needed.

There is some interest in the G4 as a P&P solution in the MR2 & celica worlds if a low cost knock interface using the standard sensor is available.

Many thanks,


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There is no intention to re-instate the analogue knock system as it did not work well with individual cylinder knock detection due to filtering on the analogue inputs.

We will be introducing onboard knock control as an option.On the G4+ units when released.

If you wish to proceed with making an interface then it needs to provide a 0.2 to 1.2ms low pulse immediately following the end of the knock window output.  0.2ms = 0 knock, 1.2ms = 1000 knock level.

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Thank you for the information on the digital input.

So what are your plans for people out there currently using an analogue knock sensor system who are now unable to upgrade firmware ?

It seems strange removing a facility as part of an upgrade regardless of how well it worked.

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