Having issues.... U0101 and U0109 Codes
11-01-2016, 02:30 PM
#1
Having issues.... U0101 and U0109 Codes
Well trying to finally get my truck started and it's throwing codes for loss of communication with the TCM and FSCM. Will start for a second then shutdown. The FSCM I checked the fuses and all that and no luck and not sure why it's throwing a loss of communication code for the TCM. I used the PCM of NC conversion kit for the 6l80 to 4l80 and doubled checked all that so not sure why it's putting out that code. I don't have my driveshafts in yet so can drive the truck and check if it even shifts and stuff.
11-01-2016, 03:28 PM
#2
Did you check power and grounds and verify the battery is fully charged? have you double checked othe connections?
Didn't you paint the frame? Is the ground attachment points raw metal? Same goes for block.
https://www.obd-codes.com/u0101
https://www.obd-codes.com/u0109
Didn't you paint the frame? Is the ground attachment points raw metal? Same goes for block.
https://www.obd-codes.com/u0101
https://www.obd-codes.com/u0109
11-01-2016, 04:32 PM
#3
Yeah I verified all the connections, grounds and all that. Painted the frame but cleaned off the parts that the grounds bolt to.
I just tested the fuel pressure and seems like the rail pressure is staying solid 57.8-58psi even when it shuts down. We scaled the injectors but might need to tweak some more as it might be the only thing wrong here. I can keep the truck running a little while longer by messing with the throttle but then it does off. Same solid fuel pressure so I'm thinking right now might just be the tune. When I swapped the TCM my tuner did a vin rewrite on the tune so it matches. Can the TCM throw both these codes or cause issues with both the TCM and FSCM communications link?
I just tested the fuel pressure and seems like the rail pressure is staying solid 57.8-58psi even when it shuts down. We scaled the injectors but might need to tweak some more as it might be the only thing wrong here. I can keep the truck running a little while longer by messing with the throttle but then it does off. Same solid fuel pressure so I'm thinking right now might just be the tune. When I swapped the TCM my tuner did a vin rewrite on the tune so it matches. Can the TCM throw both these codes or cause issues with both the TCM and FSCM communications link?
11-01-2016, 05:15 PM
#4
It's possible. These E38's are a bitch for that.
I bricked 2 in a aftermarket swap after attempting to load a tune that was supplied by a vendor.
Apparently the 6L80E transmission has to match what your flashing. The mail order tune was from a camaro or something but the trans was from a silverado.
No Help from Hp Tuners or the Vendor with the issue. 4 credits down the drain. Had to get a real tuner involved locally.
We had to flash the used ECU with the matching vin from the trans with a Gm calibration first. Then we modified that calibration to match the mail order tune specs.
I bricked 2 in a aftermarket swap after attempting to load a tune that was supplied by a vendor.
Apparently the 6L80E transmission has to match what your flashing. The mail order tune was from a camaro or something but the trans was from a silverado.
No Help from Hp Tuners or the Vendor with the issue. 4 credits down the drain. Had to get a real tuner involved locally.
We had to flash the used ECU with the matching vin from the trans with a Gm calibration first. Then we modified that calibration to match the mail order tune specs.
11-01-2016, 07:59 PM
#5
Its fixed and runs great!!!
Ok heres what the problem was. The codes were permanent DTC codes that display when a loss of communications happens. Basically at some point when I was testing everything prior to start up the ECM had power and I had the TCM and FSCM unplugged. When that happens it puts a "permanent" DTC of Loss of communication to these systems. You can't clear these codes with a scan tool or even HP Tuners. My tuner came by the house today and told me they clear themselves after a few run cycles. As far as the truck starting and shutting off it was a lean issue. We pulled fuel since I went with the big FIC 225lb injectors but pulled too much so it was just too lean. Added fuel to the tune and it started up and idled like a champ. Idle oil pressure was 48 and everything was perfect as far as the new motor goes. Super happy it was a easy fix.
Ok heres what the problem was. The codes were permanent DTC codes that display when a loss of communications happens. Basically at some point when I was testing everything prior to start up the ECM had power and I had the TCM and FSCM unplugged. When that happens it puts a "permanent" DTC of Loss of communication to these systems. You can't clear these codes with a scan tool or even HP Tuners. My tuner came by the house today and told me they clear themselves after a few run cycles. As far as the truck starting and shutting off it was a lean issue. We pulled fuel since I went with the big FIC 225lb injectors but pulled too much so it was just too lean. Added fuel to the tune and it started up and idled like a champ. Idle oil pressure was 48 and everything was perfect as far as the new motor goes. Super happy it was a easy fix.