Hey Hoople, Isn't pin 14 the 5.0V power pin? Will this power pin ring out to ground?
Yes, pin #14 is +5 reference and you do want to ring out that wire to ground. Let me explain.
Lets assume that all bikes (your 2005, OP's 2007 & my 2009) are all the same and pin #14 is the +5 voltage reference (regulated supply voltage by ECM). This +5 voltage reference is generated by the ECM. It is a regulated voltage, meaning it will remain at +5 regardless of battery voltage or what the charging system is putting out. It is a precise, regulated, reference voltage. Note that the "Return" side of this voltage is NOT frame ground. There is also a dedicated return ground reference for the outgoing +5 reference voltage. In my case (2009), it is pin #26. That shows you just how important the return voltage value is to the ECM. The ECM may send out something like 4.95 volts and what comes back may be 3.75 volts, which may equal a value of 197*F of cylinder temperature. A reading of 3.65 volts (1/10 difference) would equal a completely different temp value. Small amounts can make a big difference. Therefore wire resistance itself starts to play an important roll in the readings the ECM sees.
The difference between 11.6 volts and 11.9 volts on a headlight bulb would not really matter in most cases and usually can be overlooked. That is not the case with Map sensors or TPS sensors. A tenth of a volt counts. The wire itself, crimped pins, plug-able connectors, moisture, oxidation, wire splices and leakage to ground all start to play a big roll when it comes to sensor readings which use a reference voltage.
"Ringing out" is term used to verify the quality of the conductor in question. The wire itself and any connectors that begins at pin #14 of the ECM and terminates at the sensor can have issues. It must be checked for both resistance and leakage to frame or reference ground. If either case exists, the ECM will look at that fault and interpret it as just another good sensor reading.
In this case, to ring out (quality check) that all important +5 supply wire,, disconnect it from both ends. Disconnect the ECM plug and disconnect the temp sensor plug. Remember, as in this case, a wire may branch out to other sensors. The +5 reference for my bike feeds 3 sensors. The map, VSS, and engine temp sensors. That means before you can ring out the wire, ALL 3 sensors must be disconnected. Once you have that wire completely floating above the bikes wiring harness, you can check it for integrity. That means NO leakage to ground and VERY low resistance from pin to pin. Readings must read the theoretical limits of your meter. In most cases that will be 20 mega ohms for "infinity" and 1 ohm for a "dead short". A readings of 10, 5, or 22 ohms is Low but it is not ZERO ohms. A reading of 7 mega ohms is High but it is not infinity. The wire must meet the limits of your meter. (20 mega ohms and 1 ohm)
Yes, it's a lot of work but with the OP's thread there was a decision of whether the ECM was going to be replaced ($$),, therefore every other possibility had to be eliminated.
As for your P1353 code. Since combustion efficiency is detected via ION sensing, I would not change or touch anything until I knew what the compression and leakdown was of the engine. Not only the absolute Value, but if the two cylinders are near equal.