A4 Transmission Shifting Problem
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Joined: Apr 2007
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From: Chico California
A4 Transmission Shifting Problem
I recently swapped out a 2.73 differential on my 2004 C5 with an auto transmission to a 3.42 diff. I sent the PCM off on a mail order tune. The tuner over looked the gear scaling by accident.
I took the car home and, not knowing about the scaling, I tested it out WOT to see how my new setup worked. After flooring it the trans dropped all the way down to second and bounced off the rev limiter without shifting back out. Being an auto I had never paid attention to the tach before and didn't realize I was bouncing of the rev limiter. It took me a couple of times to figure out what the hell was going. I thought the rear end might be bad. It seemed to shift okay driving normal. WOT was no good.
The scaling was corrected and the tune was given the green light as okay to go. I'm still having the shifting problem and now from a stop in drive the first 2 shifts are very hard.
Could the WOT with the wrong scaling have damaged my transmission?
What's the best course of diagnostic action from here?
I pulled the Diag Codes and have 2.
A6-SCM-B2606 H C
10-PCM-P0894 C
Any thoughts would be greatly appreciated.
I took the car home and, not knowing about the scaling, I tested it out WOT to see how my new setup worked. After flooring it the trans dropped all the way down to second and bounced off the rev limiter without shifting back out. Being an auto I had never paid attention to the tach before and didn't realize I was bouncing of the rev limiter. It took me a couple of times to figure out what the hell was going. I thought the rear end might be bad. It seemed to shift okay driving normal. WOT was no good.
The scaling was corrected and the tune was given the green light as okay to go. I'm still having the shifting problem and now from a stop in drive the first 2 shifts are very hard.
Could the WOT with the wrong scaling have damaged my transmission?
What's the best course of diagnostic action from here?
I pulled the Diag Codes and have 2.
A6-SCM-B2606 H C
10-PCM-P0894 C
Any thoughts would be greatly appreciated.
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Joined: Aug 2011
Posts: 4,450
Likes: 410
From: Portland OR
Is the trans stock or modified?
Who is doing the tuning?
Perhaps the line pressures were increased too much and the shift times shortened.
Can you ask the tuner how he set all of that up?
Ron
Who is doing the tuning?
Perhaps the line pressures were increased too much and the shift times shortened.
Can you ask the tuner how he set all of that up?
Ron
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Joined: Apr 2007
Posts: 97
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From: Chico California
A local tuner, Mark Romans knew exactly how to fix it. It's dialed in and running like a champ. Here's what he did.
Mail order tune - Mark's adjustments
Rev - Trans = 14.6328 Mark adjusted it to 11.695
Trans Revolution/Mile 2,120.3905 Mark adjusted it to 2,652.8315
I think those 2 are in the TCC Slip Table?
He had to lower the WOT mile per hour settings for 1st to 2nd, 2nd to 3rd, and 3rd to 4th shifts. The gear scaling, they said that was all that was needed, wasn't enough. It was also running too rich and pinging. He said the performance parameters looked stock and not tweaked for higher performance.
He has is it dialed and it's running great. I hope it helps you with your problem.
RonSSNova, thanks for being willing to take a crack at it. I didn't want to come off like I was bad mouthing the mail order tuner, so I wanted to leave their name out of it. They said I could send the PCM back and they would program it back to stock and give me my money back. I didn't want to send it back, so I just ate the fee and moved on. I'm glad I did. Now I have the higher performance parameters set, too.
Sacramento area tuner Mark Romans has a stellar reputation. He absolutely lived up to the billing, and is a hell of a nice guy to boot. Highly recommend.
Mail order tune - Mark's adjustments
Rev - Trans = 14.6328 Mark adjusted it to 11.695
Trans Revolution/Mile 2,120.3905 Mark adjusted it to 2,652.8315
I think those 2 are in the TCC Slip Table?
He had to lower the WOT mile per hour settings for 1st to 2nd, 2nd to 3rd, and 3rd to 4th shifts. The gear scaling, they said that was all that was needed, wasn't enough. It was also running too rich and pinging. He said the performance parameters looked stock and not tweaked for higher performance.
He has is it dialed and it's running great. I hope it helps you with your problem.
RonSSNova, thanks for being willing to take a crack at it. I didn't want to come off like I was bad mouthing the mail order tuner, so I wanted to leave their name out of it. They said I could send the PCM back and they would program it back to stock and give me my money back. I didn't want to send it back, so I just ate the fee and moved on. I'm glad I did. Now I have the higher performance parameters set, too.
Sacramento area tuner Mark Romans has a stellar reputation. He absolutely lived up to the billing, and is a hell of a nice guy to boot. Highly recommend.
