Here are some basic screen shots of CID and Fuel Delivery Signal. All the images have figure references and a brief comment.

The CID signal appears to be very noisy. Further investigation shows us that there is more to CID than meets the eye. Considering the possibility of current mode logic (perhaps ECL) a 500 ohm resistor was placed in series with PCM CID and IDM CID to create a voltage potential. If the signal is conventional voltage potential then the resistor will not create a substantial voltage drop across the resistor. If the signal is using current then a considerable voltage drop will develop across the resistor giving us a virtual ground and potential point to obtain a signal on scope. Doing this another signal was found on the CID wire. Figure 1-G is a screen shot of the current mode signal.

Study Figure 1-G very closely, then study Figure 1-A. Both of these signals were taken from the same wire with the same divide time. Figure 1-G is not 50% duty cycle as it is in Figure 1-A. This suggests that the resistor did in fact decompose a current mode signal. We do not know the exact nature of this signal as it may be one of any number of current mode topologies(ECL, PECL, PMECL, LVPECL, LVPMECL, DIFF-LVPECL...) For simplicity purposes we will refer to this signal as CML. Our best guess to date is that this CML signal is somehow used to verify PCM-IDM link, or binding. Note the sharp transients in Figure 1-G. These transients are believed to be induced voltage spikes from the fly back of the fuel injectors.

Figure 1-H is a high voltage injector signal. The signal peaks and then slowly drops off as the injector becomes saturated, then it abruptly oscillates prior to the injector switch off. This may be the result of split shot injectors. The injector peaks with voltage, then begins to saturate at some point in the middle of the drive signal (voltage leads current in an inductive circuit), then for a moment the injector mechanically weakens the load in bypassing high pressure oil, as oil pressure builds up once again a load becomes present. And finally the injector is switched off giving up the stored energy in fly-back. Without going into too much theory, the fly back is a negative potential that approaches infinity as an induced magnetic field collapses. Special consideration must be taken in the drive electronics to accommodate such a spike. These considerations can be found else where on this site.

NOTE:

The high voltage drive signal contains a lot of very valuable information regarding the injectors, oil pressure, and reaction time. This is something that deserves more attention.