M1097A2

[Chad Lares]

Doing a restoration right now on yet another gov planet purchase. Transmission light comes on after start but I've found posts on here talking about possible fixes for that. Ordered a new TISS and as soon as I find out what relay it is that people are also talking about that sits behind the battery box, I'll order that too.

 

[Mogman]

If you have not read the codes how is it you think you need a TISS or a relay????
One BIG mistake many folks make is just start willy nilly replacing parts, this can and OFTEN leads to multiple issues, troubleshoot the problem and fix it right.
EDIT, there are at least two dozen different things that can cause a transmission trouble light.

 

[Wildland]

I'm new to humvees too, where can I purchase a code reader and where do I connect it to my 07 1097R1? Thank you.

Sent from my SM-A716V using Tapatalk

 

[Chad Lares]

Yea, sounds like I need to buy a code reader too.

 

[Mogman]

You do not need a code reader, the instructions are in the trouble shooting guide I posted above.

 

[Mogman]

Start on page 60

 

[Mogman]

It is still a good idea to wait 90 seconds ANY time the run switch is turned off before turning it back on again, unplugging the glow plug controller is supposed to protect the glow plugs but I would not trust it.
That goes for the entire time you own the HMMWV, ALWAYS wait 90 seconds after turning the run switch off or you can fry your glow plugs.

 

[Westo]

Doing a restoration right now on yet another gov planet purchase. Transmission light comes on after start but I've found posts on here talking about possible fixes for that. Ordered a new TISS and as soon as I find out what relay it is that people are also talking about that sits behind the battery box, I'll order that too.

As far as I understand the relays, the only ways it could fail are stuck on or stuck off. If it were stuck on, the TCM and trans would always be getting power, so the light would be on even when the truck is off. If it were stuck off, there wouldn't be any power going to most of the trans parts even when on, including the lamp.

 

[Chad Lares]

You do not need a code reader, the instructions are in the trouble shooting guide I posted above.

I'd rather have the code reader. What are they 300?

It is still a good idea to wait 90 seconds ANY time the run switch is turned off before turning it back on again, unplugging the glow plug controller is supposed to protect the glow plugs but I would not trust it.
That goes for the entire time you own the HMMWV, ALWAYS wait 90 seconds after turning the run switch off or you can fry your glow plugs.

The book is really cool! Unfortunately, when I see online about how everyone is reading codes after jumping the A & E pin, cool flashing lights from the transmission lights, I still haven't found the part that tells me what all the flashing lights mean. Three flashes + this or whatever, that kind of thing. Probably one of those things that experienced guys take for granted but new guys don't know what you're talking about.

 

[Mogman]

You take the code and look up what it means on the very next page of the troubleshooting guide, page 61 and then that page tells you what page to go to to troubleshoot that code.
They do not make a code reader for this application as it just is not necessary.

 

[Mogman]

Read the troubleshooting guide

 

[Coug]

The book is really cool! Unfortunately, when I see online about how everyone is reading codes after jumping the A & E pin, cool flashing lights from the transmission lights, I still haven't found the part that tells me what all the flashing lights mean. Three flashes + this or whatever, that kind of thing. Probably one of those things that experienced guys take for granted but new guys don't know what you're talking about.

Try looking at page 33 of the troubleshooting guide for what the codes mean, and the pages after that for descriptions of the code s

 

[SmartDrug]

HMMWV transmission code reader:

 

[Chad Lares]

I did that. made a video. No flashing codes at all. Transmission light just stays on.

 

[Chad Lares]

I did that. made a video. No flashing codes at all. Transmission light just stays on.

 

[Mogman]

I did that. made a video. No flashing codes at all. Transmission light just stays on.

OK then it is time to get out the meter and make sure the two sources of power and the grounds are good, if that all checks out and you are positive you are doing the jumper correctly then the TCM is likely bad, you should also inspect and re seat the connectors on the inside and outside of the TCM box.

 

[Mogman]

All the wiring diagrams are in that troubleshooting guide, there is 12V continuous to one pin and switched 12V to a different pin on the TCM
If you have not already done so open the box and make sure there was no water intrusion into the box.

 

[Mogman]

I'm new to humvees too, where can I purchase a code reader and where do I connect it to my 07 1097R1? Thank you.

Sent from my SM-A716V using Tapatalk

If your M1097R1 has a three speed (no park position) then you do not have a TCM, the three speed is all mechanical

 

[REF]

I had a problem with my RPM sensor, My trans light came on when key was on, and stayed on with the engine running. Fixed the RPM sensor wiring and the trans light went off when the engine started. When working correctley the trans light should come on with the ignition and go out when the engine starts.
Note: with the trans light on all the time the trans worked and shifted through the gears but the torque converter would not lock up, Mt trans didn't throw any codes either.
Might be worth a look.

 

[Mogman]

I had a problem with my RPM sensor, My trans light came on when key was on, and stayed on with the engine running. Fixed the RPM sensor wiring and the trans light went off when the engine started. When working correctley the trans light should come on with the ignition and go out when the engine starts.
Note: with the trans light on all the time the trans worked and shifted through the gears but the torque converter would not lock up, Mt trans didn't throw any codes either.
Might be worth a look.

If you cannot read codes then there is no reason to go any farther until you can, if the TCM will not recognize being put into diag mode it will not operate the transmission.
BTW there are many codes that do not illuminate the trans light, if you do not read them you have really no idea if you have any or not, if the transmission is acting up at all one should read the codes.