Humvee / HMMWV - 4L80-E TCM Diagnostic Code Retrieval (using a jumper wire)

Quick video to show how to retrieval diagnostic codes from the TCM of the 4L80-E transmission that 4 speed Humvees use.
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[@scottspencer3024]

Thanks for the helpful video. I'm going to use it to inspect a M1097A2 that I'm hoping to buy.

[@Subgunman]

Thanks for the info! Trying to learn as much as possible before investing in the ultimate truck!

[@class3333]

That was a very helpful and also straight to the point video - thanks for posting

[@BMD11000]

I appreciate that! It was my pleasure posting it.

[@cruiez2008]

Thanks for sharing

[@BMD11000]

My pleasure!

[@mw2584]

I've got an M1165 that won't go over 30mph. So followed all your steps exactly. My wait light doesn't flash. My trans light doesn't blink. Instead I get the regular routine of the wait light being solid for a couple seconds as if it's running the glow plugs, and the trans light never turns on/blinks at all. So I'm not sure how to troubleshoot from there with the jumper cable in slots A & E. I tried this by keeping that TCM box plugged in like you did, and also tried it with the main cable unplugged to that TCM box. I get the same results trying both. Any suggestions? It's in park, with parking break on, & tried various jump cables, no luck. I really don't understand why the glow plug wait light isn't flashing with that glow plug controller disconnected under the hood???

[@BMD11000]

I wish I knew more and could help but I really don't know what to suggest.

[@oscarvazquez-od5gd]

check if the trans circuit breaker is tripped (under/behind passenger seat near battery box) if not check the resistance on the circuit breaker. if thats good check the wires for ohms and voltage then go from there

[@skmrinc4247]

How do you clear the codes? Can you disconnect / reconnect TCM or simply disconnect batteries? Or do you need scan tool?

[@BMD11000]

Fortunately, I didn't have to get that far, so I'm unsure of the answer. I found some great information though on the GearReport site. Maybe the answer can be found there.