I know this post is ultra-old, but I wanted to add some info based on an experience I had with my '92 Toyota Pickup.
Here it is in a nutshell...you'll see how it applies to the Honda Odyssey after reading the whole post here.
SYMPTOM: Difficult starting
After literally having my dashboard pulled completely out to facilitate checking every applicable circuit and wire, here's where I discovered my problem...
PERTINENT TEST PERFORMED: Ohmed the positive battery cable, and it had acceptable resistance. I had already done this several times mind you. Also keep in mind the battery cable was at ambient temperature, and the ballast resistor in the digital multi meter (by its very purpose) causes the DMM to send only a very small current through the wire being tested so as not to affect the measurement. Both the temperature issue and the "small measuring current" issue become important next...
FINAL RESOLUTION: I deduced finally that the battery cable must be bad. I opened up the red PVC insulation on the battery cable and discovered very heavy green-colored corrosion all along the length of the cable. Green-colored corrosion, which I assume was some type of oxidized copper compound (likely copper sulfate, with the sulfate being provided by the sulfuric acid in the battery) had wicked its way in between the void spaces of the stranded 00 gauge wire. I couldn't see the corrosion due to the insulation covering the wire. I replaced the battery cable and the problem was resolved.
COMMENTS: I wasn't able to determine the cable was bad using the DMM because (1) the battery cable was not at operating temperature, and (2) the measuring current did not accurately replicate the high current that flows in this cable during starting. At operating temperature under the hood, the resistance values are much higher, since resistance is typically proportional to temperature usually according to a temperature-dependence law such as R(T) = R(0)*[1 + alpha*(T - T0)], where:
R(T) = The resistance of the wire (in Ohms) at the desired operating temperature.
R(0) = The resistance of the wire (in Ohms) at a specific reference temperature.
alpha = The temperature coefficient of resistance (in units of inverse temperature).
T = The desired operating temperature (in either degrees C or Kelvin).
T0 = The specific reference temperature (in either degrees C or Kelvin).
You can only get away with using degrees C in this case (if you choose) because it is a temperature DIFFERENCE, not a ratio. If you always use Kelvin, you will NEVER get the problem incorrect, so I recommend using Kelvin.
For (2), there is a similar relationship for how resistance in a resistor (my battery cable was a resistor essentially) changes with current; however, it is a NONLINEAR relationship. P = I^2*R or R = P / I^2. The power (P) in this case is the thermal (a combination of conductive, convective, and radiative) energy dissipated from the battery cable as it heats up due to high current flow (called Joule heating).
APPLIED TO THE HONDA COIL: (1) Resistance measurements at ambient (room) temperature from a "bad" coil may reveal good readings. The coil needs to be measured for resistance at the operating temperature--the best way to do this is to run the vehicle (if you can) until the coolant fan (not the A/C fan) cycles three times. This will ensure the engine is at full operating temperature. Also, leave the hood (aka bonnet) closed during this engine warm-up. Turn the engine off, open the hood, unplug the coil connector, and measure the resistance. I don't believe there is likely any corrosion inside the coil since it is a sealed unit. The more likely scenario is a broken primary or secondary winding that makes good contact at room temperature, but spreads apart due to thermal expansion at operating temperature--unless the windings are shellacked or otherwise insulated from each other, the primary or secondary coil is probably taking a 'shortcut' when the wire break spreads apart at operating temperature.
This is a frustrating thing on these Odyssey's--I've replaced three of the them now. I will perform a careful failure analysis on the next failed coil to determine the source of these failures. I will report out what I find.
Also check your associated ground connections! On the 2009 Odyssey, there is a thermal connection (which I assume means a soldered connection) directly underneath the throttle body--it is denoted S1. If you get an entire bank of coils (the rear one which is cylinders 1, 2, and 3) failing the drop cylinder test, but all three in the front bank are passing, it is likely S1 or G101, since they both feed just the rear bank of coil packs. Study the electrical schematic--it reveals a LOT.
A little off the subject, but I also discovered that if you don't clip the red positive terminal cover over the battery's positive terminal, you will get arcing from the positive battery terminal to the underside of the hood. The telltale for this is if you smell ozone.
I keep learning more and more about these finicky minivans.