Need assistance have a M1097 A2 in Limp mode

[Mfoley]

Purchased this one knowing it was not running and had been pretty well cannibalized. I have gotten it back together and it is now running and moving well just 2nd gear. I realized I am not getting ignition power to the trans or the TCM. I replaced the transmission relay and now have power at 291C with the ignition on. I also have power at the brake switch and trans lamp. However the trans lamp is not coming on. No power on transmission J1 -E (290D) or TCM- J (291-D). I do have 12v battery on 537-D at TCM .
I have traced the wiring harness and cannot find any points that look damaged/ ripped or disconnected. The wiring diagram shows power for these 4 connections are coming from lead 3 at the trans relay and split off somewhere in the wiring harness… I’m assuming. Or do they connected somewher? What am I missing? I downloaded the transmission troubleshooting guide and tried jumping the test port on the TCM to get the trans light to come on But without ignition power does this test work?
I definitely would appreciate any help. Thanks Matt

 

[Mogman]

If you do not have a trans light then going into diag mode will not make any difference.
Unhook the batteries then remove the main harness connector at the TCM box, reconnect the batteries turn the run switch on (you should have the TSU disconnected while you are working on electrical issues)
With the run switch on short pin U in the connector to ground, if the MIL light does not come on you have ether no power to the light or the wire is bad to pin U or a bad light.
If the light works then you likely still have a power issue to the TCM, there is switched and non switched 12V going to the TCM.
You should have a MIL light when the run switch is on and the engine is not running, you need to figure out why first as it is the most important diag tool you have for this trans.

 

[Mfoley]

Hi Mogman,
Thanks for the help! I will post my results as soon as I get a chance to do this.

 

[Mfoley]

finally got a chance to work on this.

Grounding the TCM at U turns on the mil light. I have 12v battery at Z but nothing on J with ignition on. Ground on a & b are good.
Im assuming my next step is figuring why I don’t have ignition 12v on J but I do have it coming out of the trans relay?
Thanks for your help!

 

[Mogman]

finally got a chance to work on this.

Grounding the TCM at U turns on the mil light. I have 12v battery at Z but nothing on J with ignition on. Ground on a & b are good.
Im assuming my next step is figuring why I don’t have ignition 12v on J but I do have it coming out of the trans relay?
Thanks for your help!

Check the wire numbers connected to the relay, someone may have plugged in the wrong wire.

 

[Mfoley]

290B/291B Go to 4. 290C/291C. Go to 3

 

[Mfoley]

Mogman
I have looked over the wiring harness and cannot find any points that look damage. the wiring diagram on pg 114 of the manual shows the 12v power on 291c coming together at some point. Since I have power at the bake switch and the trans light but not at the trans and TCM where should I start looking for a problem? Could this be at the glow plug controller? Or could I be missing a componet that was canabolized?
thanks for your help
Matt

 

[Mogman]

Check continuity from the 290C/291C at the relay and the 290C/291C at the TCM plug, I had one trans that the wire was severed.
There should not be any more components involved.

 

[Mogman]

Mogman
I have looked over the wiring harness and cannot find any points that look damage. the wiring diagram on pg 114 of the manual shows the 12v power on 291c coming together at some point. Since I have power at the bake switch and the trans light but not at the trans and TCM where should I start looking for a problem? Could this be at the glow plug controller? Or could I be missing a componet that was canabolized?
thanks for your help
Matt

You meant page 141 yes, just want to make sure we are looking at the same TM

 

[Mfoley]

Yes, sorry.
No continuity from trans relay to TCM plug or to the trans connetion. I will check from TCM plug to transmission connection and see if they have continuity.
Thanks again for your help

 

[Mfoley]

Ok. Did a lot checking today. I went over the entire wiring harness and there is no damage /kinks or nicks. Everything is plugged in with good connections. So I went back to the TM (pg 141). and looked for power First on TCM plug J1. I found ingition power on j . I was looking at J before. (I’m getting old). Now at the transmission plug I still don’t have 12v on E but I found 12v on L. This is with the TCM J1 unplugged. Power should only flow between the two?
I checked continuity And found it from the transmission plug E to TCM e………and from L to j
It appears that my transmission plug E and L are switched. Does this make any sense?

Thanks again
Matt

 

[Mogman]

Look for wire tag 291 in the bundle at the TCM plug and see if it is in fact miss wired.
You may need to cut back the loom a little bit to get enough wire to manage.
Use your VOM lead to pierce the insulation and check continuity with the plug removed from the TCM

 

[Mfoley]

Will do

 

[Mfoley]

Definitely missed wired. 290D is plugged to L and 923 is in E. I’ll get that repinned and see if it will shift!

Thanks for your assistance

 

[Mogman]

Definitely missed wired. 290D is plugged to L and 923 is in E. I’ll get that repinned and see if it will shift!

Thanks for your assistance

It does not appear L is even supposed to be in use.