Also here is a Bulletin from GM talking about the differences in internal harnesses.
https://static.nhtsa.gov/odi/tsbs/2020/MC-10171294-9999.pdf
Type: Posts; User: blackdog76
Also here is a Bulletin from GM talking about the differences in internal harnesses.
https://static.nhtsa.gov/odi/tsbs/2020/MC-10171294-9999.pdf
I emailed Bill and he said he didn't know what the 81 82 error codes meant. I'm going to try to adjust the shifter and see if anything changes as far as the shifter errors.
I have a 2015 L86 8L90 combo in a swap car. I had to source my ECM and TCM from a 2015 Escalade. After sending them both off to my tuner and getting them tuned (including having the TUN flashed from...
Ok so I might have an idea of what’s going on. The P18C2 is a trans gear position switch code. Apparently there are two different range switch harnesses for the 8L90. A 4 pin and a 10 pin.
Here’s...
Unfortunately not fixed. I added the PRNDL status channel and can see it shifting as I move the floor shifter. When I try to go into drive or beyond I get the message unknown 81 and unknown 82. With...
Also have some codes still. The last one is a range sensor code and will set a P0700 as well when I try to shift. I’m guessing this is because I don’t have the shifter that the system is looking for?...
Ok so I tried to do the fast learn and since I couldn't engine brake the car to heat it up (wouldn't go into drive) achieving 165 degrees took almost an hour! And the engine temps were around the 215...
My tuner told me to add transmission parameters but I’m not that versed with HPT yet.
They are the same. I bought a matched set from a 2015 Escalade with a 6.2 8L90. Then I sent both to my tuner and had him flash the TUN from the sticker on the side of my trans also.
Can someone...
Ok so there is no more communication errors with the TCM but now it won?t move in any selected gear. My gear selector on my Dakota digital gauges is reading correct when I move the shifter and the...
Can HP tuners do that or is that a dealer only thing?
I had to get a T87 separate from the trans for my swap (no ECM or TCM included). Do I need to have the TCM flashed with the TUN on the sticker on the side of the 8L90 or can I just do a fast learn?
I did an idle clean and reset the fuel trims. Runs great now and no more hanging rpms.
will do, thanks
Log File
117437
I have the following hardware installed for an L86 8L90 swap into a 67 Camaro.
L86 with: LT2 intake, Spectre CAI from 2016 SS Camaro, Speed Engineering (short) headers, 3" exhaust with X pipe...
I installed a used TCM from a 2015 that had an 8 speed and no more comm errors.
The TCM was the issue. An Allison TCM doesn’t like to written over apparently.
I think I found the answer. The codes I am getting are Allison trans codes. From what I can find, the 8L90 codes don’t match what I’m getting. Anyone have a T87 from an 8 speed truck they can sell...
In addition to the U0100 U0101 and P0073
I’m also getting some additional codes when I push the pedal and put the trans into gear with the engine running: P0700
P2635
P0657
P0706
P0708
P0751
P0762
P0842
P0843
P0872
I shipped the ECM and TCM back with instructions to flash to the same vin at the dealer and upload the TUN for my transmission to the TCM. I got them back, reinstalled them and same exact issue.
I’m willing to ship my ECM TCM to someone who can do it.
San Francisco area
I spoke with my tuner who said that I need to bring the ECM and TCM into a dealer and flash everything to the same VIN. The closest dealer to me said they can try to program a new vin but it probably...