2003 throwing P2810

[Dallas S]

Just bought the truck, dont know much about it. tranny is built with altos, transgo, cutback, triple disk. but I believe the tranny is an 01, with 03 bellhousing for the oil lines.

truck runs and has all gears, but wont rev over 2-2200rpm.

from what I can gather the G soleniod isnt factory till lly's? any ideas?

 

[Mike L.]

Just bought the truck, dont know much about it. tranny is built with altos, transgo, cutback, triple disk. but I believe the tranny is an 01, with 03 bellhousing for the oil lines.

truck runs and has all gears, but wont rev over 2-2200rpm.

from what I can gather the G soleniod isnt factory till lly's? any ideas?

Sounds like someone flashed an '04/'05 operating system in your TCM. TCM is looking for a G solenoid and doesn't see it.

 

[Dallas S]

yup, LLY operating system. from the limited info about this code I kinda gathered it was a operating system deal, but I kept thinking the rev limit had to do with the codes being thrown-in ben's TCC unlock switch thread he mentioned this code wouldnt hinder performance tho so I was confused. and secondly, the previous owner had EFI live, wonder what the idea was behind the LLY flash

and the rev problem....... :rofl: stupid hi idle switch..... silly LB7's :spit:

 

[Dallas S]

thanks once again Mike!

 

[Mike L.]

This code will affect engine performance and give you a rough idle. I've played with this and know. Don't know the thinking behind it.

 

[Mike L.]

This code will affect engine performance and give you a rough idle. I've played with this and know. Don't know the thinking behind it.

What you can do is install a G solenoid internal harness and plug in a G solenoid and zip tie it to the pipe on valve body. This will satisfy the TCM and eliminate the code.

 

[Dallas S]

forgot about this thread. I simply reflashed an 03 operating system into the tcm. Works great now.

thanks again Mike!

 

[majateck]

I've got a similar problem. As far as I can tell the truck is completely stock. Codes are P0700, P2810 and has a lot of trouble shifting into gears. I have to really floor it to get it to shift hard into gears. I'm guessing this is limp mode?

 

[Mike L.]

Something is not stock. Without any info we have no idea.

 

[majateck]

Something is not stock. Without any info we have no idea.

Thanks for the quick reply. I'll take a look to see if I can find whatever is not stock. :thumb:

 

[majateck]

Finally got around to checking on the transmission and did some troubleshooting. I have another same year truck in the back that is just an upgraded model from this one I'm troubleshooting, so I tried swapping the (same PN) TCMs and no-go. Next I dropped the XMSN pan and cleaned all connectors, no-go. Next a performed a continuity test on the internal harness, no-go. Removed solenoid G measured resistance to be 22.9 ohms. 22-24.5 is normal so it was within specs. applied 12V and the solenoid actuated.

Still getting P0700 and P2810. My Modis Ultra shows "P2810 is set when the TCM detects an open circuit, short to ground, or short to power at solenoid G circuit for greater than 2 seconds" Also, under possible causes it shows "Open or short in circuit" or "Faulty TCM". I've ruled out the faulty TCM and contacted the previous owner who is the only previous owner. Unfortunately it was someone who owned a business and his employees worked this truck hard. No modifications were made though according to him. I guess I've got not choice but to chase down some wires.


Are there any fuses directly involved with the TCM or grounding points? If anyone has any suggestions I'm all ears.

 

[Mike L.]

On the Red connector on the TCM; check wires 29-grnd, 30-grnd, and 32-12V. These wires run from the TCM to the G and F trim solenoids. You will find your problem there.

 

[majateck]

Upon checking the wiring for the truck I found a difference in the external connector and the bulkhead plug from the internal wiring harness on pins R and S. On the trans pin R and S lead up to solenoid G. On the external connector only pin S is occupied.

I'm starting to think the TCM is programmed for this transmission. However, the truck's wiring harness was not.

Or... I just have the wrong TCM on the truck. I know there was an overlap in production with these transmissions with the solenoid G. I'm going to call a local allison shop first thing monday morning to confirm my thoughts on this.
Anyone else got any input?

 

[Mike L.]

All the '04's and some very late '03's were wired for the G solenoid. Difference was in the programming in the TCM. Only the LLY's and 8.1's were lit up. The LB7's were not. I tested this stuff 10 years ago.

 

[majateck]

My truck is an 04. Shouldn't there be 2 wires on the connector that correspond to the 2 wires on the bulkhead connector? I'm thinking about running a wire direct from the tcm to the pin on the bulkhead to see if it satisfies the TCM. Only problem I'm running into is that I don't have a diagram of the connectors on the tcm that will show me where to pin it. Do you have one available Mike?

 

[majateck]

I think I figure out the problem. I think I have a truck that was not wired for this G solenoid. Not sure. I checked wire 30 as you said Mike on the red connector to the TCM. There is no wire. Can I just run a wire to satisfy the TCM or would it possibly cause any adverse effects? I'm thinking the only thing that may have changed between these different models would be the color of the wiring and not the pinout. At least I hope so...

 

[majateck]

I finally got it guys! Ran a wire from the G solenoid (brown wire) direct to the TCM pin 30 (red C2 connector) and cleared the code P2810. Checked again to see active codes and saw this page. :thumb:

 

[Mike L.]

I think I figure out the problem. I think I have a truck that was not wired for this G solenoid. Not sure. I checked wire 30 as you said Mike on the red connector to the TCM. There is no wire. Can I just run a wire to satisfy the TCM or would it possibly cause any adverse effects? I'm thinking the only thing that may have changed between these different models would be the color of the wiring and not the pinout. At least I hope so...

We are in Ben's territory now. I think if you install the wire and make sure you have the proper internal harness, you need to make sure you have the correct TCM program.