Resetting PCM and Trans Adapts

[StevePT]

I'm reposting this question per bnaylor's request.

[BNaylor]

Hey StevePT, thanks for re-posting from the Century forum.

On your question about resetting the PCM and clearing TAPS, adaptive shift point data:

The PCM has the capability to re-learn driving habits to include shifting data and then programs the data into cells and it's stored. Its does this over one to two drive cycles. Normally, the TAPS info does not need to be cleared. However, after servicing the 4T65E tranny TAPS info should be cleared out. This includes when replacing the PCS solenoid, a rebuild, total swap out to another, replacing the torque convertor, valve body replacement, etc.

Under most circumstances you have to take your car to a GM dealer and a Tech II machine is used. The dealer may or may not charge you but I've heard of costs up to $80 to do this.

When you disconnect the positive or negative battery terminals there is no guarantee that data stored in the PCM such as DTC error codes will be cleared out. Many codes are stored but do not trigger a SES/CEL light. Tranny error codes such as P1811, etc. (shift error) do not trigger a SES light but stored to be pulled up by a scanner. Disconnecting the battery alone will not clear TAPS info.

The following procedure should clear all DTC error codes stored, clear a SES light, clear TAPS data and force the PCM into a re-learn mode.

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Disconnect the POSITIVE battery terminal.

Insert key into ignition and turn all the way to the engine start postition and hold for minimum of one minute. Of course, engine will not start.

Take key back to off position. Since the positive terminal was disconnected, the key will be stuck and cannot be removed at this time.

Reconnect positive battery terminal. Once battery is re-connected you will now be able to remove the key.

PCM will be in now be in re-learn mode and TAPS data will be cleared.

Re-start engine and it should re-learn and program TAPS info after a drive cycle of up to 200 miles or less.

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On your other question:

I believe the major difference between the 4T65E and 4T60E trannies are the fact that the 4T60E has a vaccum modulator to help control shifting firmness. The 4T65E does not have one and is fully electronic.

Hope the info helps. Good luck!






Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.