SenderGreen

Slows2k, will having the knock sensor DTC on an S2000 put it into "gimp" mode? Are there different degrees/types of "gimp" mode? What is the RPM limited to in "gimp" mode? Do you know if anything other than the RPM is affected in "gimp" (does it run rich?)? What DTC's can induce "gimp" mode, what are the most common? What the hell is the correct technical term for "gimp" mode?

Slows2k

On other Honda models a P0325 will put the PCM into a backup or limp mode. I haven't dealt with a S2k with a broken knock sensor, and I'm not about to break mine to find out.

Without the knock sensor the PCM can't modify the timing maps, which it does all the time. As far as running rich in backup, I'd be guessing at a AF ratio. the car is barely driveable when you can't get over 3K RPM.

The times my car has made it into backup has been when the Vortech timing controller wiring had a loose ground. RPM limit at 3K, untill the PCM had been powered down then stored the history DTC. I could cycle the key and continue on with the CEL on, but no 3K rev limit. This was an intermittent fault, which would only act up once every 3 months.

Any TDC or CKP code, Any MAP voltage over BARO volts as well as the prevously mentioned P0325. I'm sure there are other DTC's that I haven't come accross that will send the PCM into backup.

SenderGreen

Weird, so it only went into limp mode initially, then kept the CEL on along with a stored DTC, but removed the 3000 RPM limit on the next startup.

Thanks again for the info and answering my 20 questions.

Slows2k

Yup, the PCM was loosing the TDC sensor signal after it was allready running. The PCM pretty much freaks completely out, as TDC input is used for injector and ignition timing.

It wasn't a hard failure all the time, which is why at the next startup it came out of backup.