papanots

I have a 2002 Impala LS with 61,000 miles on it. During the last month the transmission has not been shifting smooth as usual. After driving for about 20 minutes, the shifting gets pretty brutal. From 1-2 it gives a jolt and 2-3 as well but not as bad. Sometimes, it even jolts when downshifting on deceleration. When I turn off the car and start it up 10 - 15 minutes later, the shifting returns to normal. But inevitably, the harsh shifting comes back. I had the fluid and filter changed at 52,000 miles just as recommended by GM. The fluid is red and no burned smell or particles are present on the dipstick. Naturally my warranty has already run out and the car is paid for!!

Anyone experience these symptoms?

maxwedge

Should be scanned with a trans function scanner for trans codes and to check operation of solenoids, it is possible the pressure control solenoid is going bad, a common issue on those trans.

BNaylor

I agree with MAX. Look for a P1811 DTC error code after scanning. (Maximum Adaft & Long Shift). This error code will support a bad PCS solenoid and commands maximum line pressure which causes the harsh shifting. Very common problem on a 4T65E tranny. It is a class "D" error code and does not trigger the SES light, however, will store for retrieval.

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'08 Pontiac Grand Prix GXP (Dark Slate Metallic) - LS4 5.3L V8
'08 Pontiac Grand Prix GXP (Liquid Silver Metallic) - LS4 5.3L V8
'02 Oldsmobile Alero GL2 - LA1 3400 V6
'99 Buick Regal LS - L36 Series II 3800 V6
'03 Honda CR250R MX - 2 Stroke 250cc
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Timeslip 08/12/06

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papanots

Thank you both for the precious information. I take it the solenoid is in the tranny? To the best of your knowledge, will it require a complete overhaul to get at the solenoid? Thanks again.

BNaylor

Needless to say yes and it is located in a bad spot. Access is very difficult. The PCS is located on the left hand side of the valve body underneath the side cover assembly which is on the driver's side of the car.

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'08 Pontiac Grand Prix GXP (Dark Slate Metallic) - LS4 5.3L V8
'08 Pontiac Grand Prix GXP (Liquid Silver Metallic) - LS4 5.3L V8
'02 Oldsmobile Alero GL2 - LA1 3400 V6
'99 Buick Regal LS - L36 Series II 3800 V6
'03 Honda CR250R MX - 2 Stroke 250cc
'97 Pontiac Grand Prix GTP - L67 Series II 3800 V6 Supercharged
Timeslip 08/12/06

AF Community Guidelines

ronvb

Guys,
My Impala is showing the same code.It has only acted up 2 times so far-as irregular shifting.
My question is: does this do harm to the trans if continued driving for a while or is it just a pressure issue?
thanks,
ronvb

micali

can this be done by an individual? Is there instructions on this?

troy1

Harmfull yes, it can bust the 2nd drum and do other things

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tractorboy

is it possible to just adjust the FM current, that's what it sounds like, it is only happening at a certain temp, a harsh or firm shift



across the top is the % of line pressure, down the side is trans temp and this is from a 4T65E
The higher the current the softer the shift, that's why at 100% line pressure it is max current.

troy1

Where did you get that ^^^???

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