4T65E Trans Shift Hard, P1811 DTC

[BNaylor]

Originally Posted by scorp102

You are awesome! Thank you for taking the time to show me! I will gather the parts and and get to work.

Thanks again!

You're welcome. If you need any further assistance including where to get the parts just PM me.

[gjhunter01]

Just wanted to do a follow up to the original problem. I ran the trans tune seafoam in the trans for about 2 weeks, 600 miles, and the trans worked fine. I dropped the pan and changed the oil and it sure looked dirty even though it had only 3k miles, the seafoam did the job. On BNayor's advice, I also installed the ZZPerformance kit with the spacers for the solenoid and put in 8 quarts of Dextron III (could not find Dextron IV). The trans now runs like new and the shifts are hardly noticeable. Thank you BNaylor for your help.

[BNaylor]

You're welcome and thanks for the feedback. Thats Dexron VI which is readily available at any auto parts store but no problems using the Dexron III.

About all I can say in closing is all my test vehicles are working like a champ so far racking up thousands of miles. Statistically give or take about 60% of the harsh shift, launch shudder and P1811 DTC is PCS related the other 40% internal issues such as the second clutch pack, accumulator wear or other fair wear and tear, etc. While the shift kit mod may not be the ultimate fix it sure does help and may save members a lot of money or help get many more useful miles out of the autotransaxle.

[scorp102]

I have purchased the Dexron VI and the trans filter. I ordered the shift kit from ZZP and are awaiting its arival. I tried the Seafoam Trans Tune and it only prolonged the time during an actual drive before the hard shifting returned. (It used to hard shift in about 5 min, now it is around 10min.)


I will install the shift kit as soon as it arrives and report my results from there.


Thanks again for all of your help!

[chris_eitniear]

Not to get OT, but will this mod work on pretty much any 4T65E? I have a 2000 Montana that's doing the same thing.

[BNaylor]

Originally Posted by chris_eitniear

Not to get OT, but will this mod work on pretty much any 4T65E? I have a 2000 Montana that's doing the same thing.

No guarantee the mod will work and there are variables but as far as applying it to see if it makes a difference that is not an issue. The shift kit can be used in any GM vehicle that has the 4T65E autotransaxle with GM RPO code MN3, M15 and MN7. The '00 Montana should have the M15 version of the 4T65E.

What are your specific symptoms and any DTCs stored?

[chris_eitniear]

Originally Posted by BNaylor

No guarantee the mod will work and there are variables but as far as applying it to see if it makes a difference that is not an issue. The shift kit can be used in any GM vehicle that has the 4T65E autotransaxle with GM RPO code MN3, M15 and MN7. The '00 Montana should have the M15 version of the 4T65E.

What are your specific symptoms and any DTCs stored?

Thanks for the reply.

I haven't had it scanned, but after a little stop and go traffic, I get the hard shifting on all three shifts and a whining sound. After letting it cool, its ok until it gets back into stop and go traffic again, so I'm almost sure its the PCS causing the trouble.

I had figured on adding some seafoam for a couple of weeks and then doing a fluid/filter change when I do the oil change. I thought as long as I have the pan off, I might as well try the shift kit as long as it will work with the tranny.

[BNaylor]

Originally Posted by chris_eitniear

Thanks for the reply.

I haven't had it scanned, but after a little stop and go traffic, I get the hard shifting on all three shifts and a whining sound. After letting it cool, its ok until it gets back into stop and go traffic again, so I'm almost sure its the PCS causing the trouble.

I had figured on adding some seafoam for a couple of weeks and then doing a fluid/filter change when I do the oil change. I thought as long as I have the pan off, I might as well try the shift kit as long as it will work with the tranny.

You're welcome.

High probability it is a PCS related issue especially with the combination hard shifts and whining sound. When a P1811 DTC (max adapt, long shift) sets it commands high line pressure (max) and disables shift adapts. As a result you get the hard/harsh shifts and the whining sound from the pump. The DTC sets when the PCM module sees shift timing greater than .65 seconds. What the shift kit does is firm up shifts especially the 1-2 and 2-3 and improves shift timing where the P1811 DTC does not set. As a result no hard shifts and whining sound. Now if the PCS solenoid itself is in really bad shape the mod may not help.

In your situation it won't hurt to try it since you plan on running the Seafoam and doing a pan drop service. All accumulators where the spacers are applied in any 4T65E autotransaxle are the same so there is no reason why it cannot be applied in yours.

[scorp102]

Well, I have excellent news to report! I installed the shift kit, flushed and replaced the fluid with the Dexron VI, and installed a new fluid filter. The car is shifting and running like a champ! It was ungodly the amount of gunk I cleaned out of the tranny. I am assuming the Sea Foam got most of it loose for me.

You were right about it being a DIY job even for beginners. I must admit I was alittle nervious at first, but when I got the kit, read the instructions and went to town it was much easier than I anticipated. It took me about 3 1/2 hours to do.

But I tell ya, so far smooth as a bell. So far...lol I am afraid that after I write this post Murphys Law will kick me in the rear. I feel like its almost too good to be true.

I cant tell you enough how much I appreciate your time and your help with this situation. You saved me a ton of money and a lot of hassel. Hopefully it will last a long time.


Thanks again!

[WOODS GTP]

WHAT IS A accumulator shift mod & HOW DOES IT WORK THANKS

[BNaylor]

Originally Posted by WOODS GTP

WHAT IS A accumulator shift mod & HOW DOES IT WORK

Welcome to AF.

See my posts #7 and #14 at this thread.

Basically it firms up or improves upshifts in automatic to improve shift timing to preclude the P1811 DTC from setting and the PCM module commanding high line pressure which causes the hard upshifts or even an annoying whining sound.

Also, see link below.

Click here

[Cocopelle]

Hey BNaylor,

If a person installed the ZZP shift kit simply to fix the P1811 code on an Olds Intrigue, which of the 4 shift firmness options would you recommend? (This is a daily driver with no other modifications, and not driven aggressively).

Thanks!
Cocopelle

[BNaylor]

Originally Posted by Cocopelle

Hey BNaylor,

If a person installed the ZZP shift kit simply to fix the P1811 code on an Olds Intrigue, which of the 4 shift firmness options would you recommend? (This is a daily driver with no other modifications, and not driven aggressively).

Thanks!
Cocopelle

Welcome to AF.

I would go with normal or I think number 2. Whatever the ZZP instruction sheet says or recommends. That is what I used on all GM cars modded.

[Cocopelle]

Originally Posted by Cocopelle

Hey BNaylor,

If a person installed the ZZP shift kit simply to fix the P1811 code on an Olds Intrigue, which of the 4 shift firmness options would you recommend? (This is a daily driver with no other modifications, and not driven aggressively).

Thanks!
Cocopelle

Hi BNaylor,

1st of all Thanks for your help. Here's an update on my experience. I dropped the pan and accumulator and found a broken 1-2 accumulator spring. I replaced it and also installed the ZZP shift kit with the recommended spacers. Also installed a new filter, pan gasket and Dextron VI. Things seemed great for a while. But now, I've noticed that the hard shifting will return if the car is driven enough to get hot. Any advice for me? Does the shift kit essentially override the PCS function? Is it possible that replacing the PCS might fix the problem or am I looking at something more? The 2001 Olds Intrigue has 70K miles and has never been driven hard.

Thanks again for your help.

[BNaylor]

Originally Posted by Cocopelle

Hi BNaylor,

1st of all Thanks for your help. Here's an update on my experience. I dropped the pan and accumulator and found a broken 1-2 accumulator spring. I replaced it and also installed the ZZP shift kit with the recommended spacers. Also installed a new filter, pan gasket and Dextron VI. Things seemed great for a while. But now, I've noticed that the hard shifting will return if the car is driven enough to get hot. Any advice for me? Does the shift kit essentially override the PCS function? Is it possible that replacing the PCS might fix the problem or am I looking at something more? The 2001 Olds Intrigue has 70K miles and has never been driven hard.

Thanks again for your help.

Did you get it scanned with a trans capable scan tool/scanner? See if a P1811 DTC is stored.

If the PCS is in bad shape the shift kit may not help and may not compensate for a serious PCS issue. All the shift kit does is improve shift timing to reduce or preclude the possibility of a P1811 DTC setting causing high line pressure and the hard shifts. Mainly due to slippage or minor mechanical wear. if the PCS is confirmed bad then it is best to replace it.