Ecu not communicating with transmission
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From: fbg, tx
Ecu not communicating with transmission Hi i recently upgraded my ecu car, car runs and everything but it seems to start in 3rd gear and wont downshift or upshift on its own have to manually shift thru the gears to get going. I tried using the manual controls on hp tuners to command gears and it wont go into the commanded gears. Like the ecu is not communicating with transmission. Sorry im a bit hungover and am having trouble with the punctuation lol
Last edited by hot98z28; Jun 8, 2025 at 10:34 AM.
Thread Starter
11 Second Club
Joined: Mar 2012
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From: fbg, tx
Yes i did and nothing is coming on, i also added most dtc back since whoever was building something with this ecu had turned off most of the dtc. All gauges work except for fuel and speedo is way off itll jump to 160 going like 5mph and i dont want to drive it because its raking up miles like crazy
Thread Starter
11 Second Club
Joined: Mar 2012
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From: fbg, tx
I did have an extra wire that was not mentioned in the pin out change so i just stuck it in the same spot it was in the 98 ecu. Geez here i go another 4hrs trying to find it. 🤦♂️ actually i think i did mark it i pray to god the label is still on it.
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Thread Starter
11 Second Club
Joined: Mar 2012
Posts: 158
Likes: 15
From: fbg, tx
I added copied the 98 trans file since 00 Camaro ecu came from was manual. Re did my wiring had 2 wires crossed. Car idles good now and speedo is now reading twice the speed i am going. But it takes off in 3rd gear and i have no 1st not even manually. Ill try and upload the tune its been a while
I added copied the 98 trans file since 00 Camaro ecu came from was manual. Re did my wiring had 2 wires crossed. Car idles good now and speedo is now reading twice the speed i am going. But it takes off in 3rd gear and i have no 1st not even manually. Ill try and upload the tune its been a while
That definitely has m6 trans and trans diagnostics segments. You have to remember that there are LOTS of tables that operate in the background that Hptuners does not show us. It would be best to flash in a complete file from an a4, but at the very least you should segment swap the trans segments from an a4 file. A segment swap will not cost you any HP credits.
edit-- To be more specific, you have to open your file, then open the other as a compare file. At that point you can use the segment swapper.
Thread Starter
11 Second Club
Joined: Mar 2012
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From: fbg, tx
Yes, that is exactly what you need. I pulled this one from the hptuner repository. I don't have the factory access to verify it, but it is supposed to be a stock a4 file.
edit-- To be more specific, you have to open your file, then open the other as a compare file. At that point you can use the segment swapper.
edit-- To be more specific, you have to open your file, then open the other as a compare file. At that point you can use the segment swapper.
alright its working as it should, thank you. The fuel gauge is kind of working but its off is there something i need to change?