Hyundai Repair: code 1613 on scan tool, transmission control module, signal measurement

Question
I have a 2001 Tiberon with over 65000 miles. The car has had trouble starting lately. The check engine light came on the other day and I did a check using the OBD2. The result was code 1613. It said it was something to do with the ECM. I called the dealership and they said they didn't believe me because that code did not exsist. Hopefully you have some insight into what this code is and what it means for me....Thanks

Answer
P1613 definitely exists.  When you start the engine, the TCM (transmission control module) sends a test signal along the wire to the ECM (engine control module) it uses to request the check engine lamp.  P1613 indicates that the test signal voltage is more than 120% of battery voltage.

I'd recommend clearing the code to see if it comes back.  It's possible this was a one-time error.  If it does come back, it'll be very difficult to diagnose.  The problems could be:
1.  Improper signal from TCM (defective TCM)
2.  Improper signal measurement in ECM (defective ECM)
3.  Irregular feedback from an actuator that causes bleed-over into this signal circuit in either the ECM or TCM.

The last case of this I recall was a defective TCM.  I don't recall whether I've ever seen a defective ECM with this issue.  

The feedback idea is information that was given to me by a Kia instructor.  What Kia had found was that the idle actuator resistance was low, causing bleedover in the ECM into the engine lamp request circuit.  I presented this idea to a Hyundai instructor or technical assistance representative (can't remember which) and they found the idea intriguing but had no knowledge of such a thing being the case.  Considering the computer on your vehicle is Bosch and the ones on Kias at the time were also Bosch, the similarity is enough to make me suspect the idle actuator.  You may wish to check its resistance since it's easy enough to do.

Hyundai hasn't had any significant problems with this code since about the 1997 or 1998 model year.  My best guess would be a defective TCM, but I still consider that a low percentage guess.