Wire Fox
Well-known member
- 1,252
- 161
- 63
- Location
- Indianapolis, Indiana
I'm in the parts manual right now and I've noticed this notation in two separate wiring diagrams... It looks like the wiring diagram shows the TCM having a constant 12V feed through the circuit breaker, before the relay. The transmission itself isn't powered on until the relay is closed by having a running signal. While I can see clear merit to having the TCM initialized prior to the transmission being powered-up, I have my hesitations about having the TCM stay powered at all times due to parasitic draw.
For those following along, it's pin Z on the TCM harness that goes direct to the circuit breaker, which goes direct to one battery + via 12 AWG. My best guess to explain why this would be correct is if there is an internal relay/transistor in the TCM that won't draw power until pin i receives a 12V signal from the relay being closed.
EDIT: Sorry about the hopeless schematic image size. Though, I think if you've got the knowledge of the wiring of the TCM, you probably already have this schematic readily available in the TM... I'm going to bed now, so maybe I'll put a bigger one up in the morning if it's needed.
For those following along, it's pin Z on the TCM harness that goes direct to the circuit breaker, which goes direct to one battery + via 12 AWG. My best guess to explain why this would be correct is if there is an internal relay/transistor in the TCM that won't draw power until pin i receives a 12V signal from the relay being closed.
EDIT: Sorry about the hopeless schematic image size. Though, I think if you've got the knowledge of the wiring of the TCM, you probably already have this schematic readily available in the TM... I'm going to bed now, so maybe I'll put a bigger one up in the morning if it's needed.
Last edited:
