‘01 Stop/neutral TCM Update

[cham]

Want to thank everyone who has helped me so far. I recently just figured out the reason for a delay in engagement when pulling away from a stop light. I thought it was brakes not lifting-off for a while, but I found out about the Stop/neutral function on ‘01 P2 cars.

Currently have the vehicle at a dealer trying to get the update and I’ve been told twice now they can’t update the car because it’s old or they don’t know what I’m talking about. I also asked for them to do any latest TCM updates if it hasn’t had it along with the stop/neutral. Getting the cold shoulder.

I’m curious if anyone might know the latest part numbers so I can steer them in the right direction. Is the stop/neutral function delete within the latest TCM update?

I found one forum claiming the stop/neutral removal software is P/N: 30646691 while the TCM latest software is P/N: 30677036. This was a post from 2013 though, and seems to be a UK forum. I’ve also seen posts claiming the most recent TCM update contains the stop/neutral removal software within it. Any ideas?

[dikidera]

while I do not have a old TCM dump, it really is down to 1 byte configuration change to disable Neutral Control.

You change one byte from a 1 to a 0. And that is it. The problem of course is flashing it.

[cham]

That is very funny that is literally all it takes. Contacted another dealer outside of my town and they gave me the correct info. Turns out that TJ 16761 is the PDF/Document outlining the software, and P/N 30677036 is the correct TCM update which includes the stop/neutral control fix. Just providing this info for anybody in the future. Unfortunately the dealer was not able to figure it out by the end of the day so I have to bring it back; I'm just glad I have a heading now.

[cham]

Just an update for the update; the dealership ended up doing instead what's called a Service 2.0 software update. This apparently includes the P/N 30677036 Neutral/Control software, along with anything else it might need. This includes updates for other modules like the ECM or ETM if your car needs them. It's free but 1 hour of labor still applies.

Car is back and problem solved, no more delay in engagement when pulling away from a stop light. Surprised the transmission survived this long with the issue. Vibrations at a stop light are no worse either, which makes me wonder why Volvo included this feature to begin with.

[dikidera]

Just an update for the update; the dealership ended up doing instead what's called a Service 2.0 software update. This apparently includes the P/N 30677036 Neutral/Control software, along with anything else it might need. This includes updates for other modules like the ECM or ETM if your car needs them. It's free but 1 hour of labor still applies.

Car is back and problem solved, no more delay in engagement when pulling away from a stop light. Surprised the transmission survived this long with the issue. Vibrations at a stop light are no worse either, which makes me wonder why Volvo included this feature to begin with.

I can help answer why they did it. It's in the patent files



They did it for a 1.5% improvement in fuel economy. They also introduced slip lockup for a 3.5% improvement in economy. All these stuff as you saw only backfired with the neutral control having issues and slip lockup wearing away at the TC, introducing metal dust in the transmission oil which likely lead to sticking solenoids.

[cham]

@dikidera What is the function and purpose of the Slip Lockup you are referring to? Does the update I just received also remove that? I had this funny symptom when pulling away from a stop, even after Drive would re-engage out of Neutral, the car would kind of pulsate forward a little before fully engaging. This only happened when the car had been driving for 30 minutes or more though weirdly enough.

Haven't been able to drive the car this long yet to see if it's gone, but the neutral/control at least is definitely gone.

[abscate]

Just an update for the update; the dealership ended up doing instead what's called a Service 2.0 software update. This apparently includes the P/N 30677036 Neutral/Control software, along with anything else it might need. This includes updates for other modules like the ECM or ETM if your car needs them. It's free but 1 hour of labor still applies.

Car is back and problem solved, no more delay in engagement when pulling away from a stop light. Surprised the transmission survived this long with the issue. Vibrations at a stop light are no worse either, which makes me wonder why Volvo included this feature to begin with.

I can help answer why they did it. It's in the patent files



They did it for a 1.5% improvement in fuel economy. They also introduced slip lockup for a 3.5% improvement in economy. All these stuff as you saw only backfired with the neutral control having issues and slip lockup wearing away at the TC, introducing metal dust in the transmission oil which likely lead to sticking solenoids.

I think I’m going to add this to my lecture on how not to visualize data

[dikidera]

@dikidera What is the function and purpose of the Slip Lockup you are referring to? Does the update I just received also remove that? I had this funny symptom when pulling away from a stop, even after Drive would re-engage out of Neutral, the car would kind of pulsate forward a little before fully engaging. This only happened when the car had been driving for 30 minutes or more though weirdly enough.

Haven't been able to drive the car this long yet to see if it's gone, but the neutral/control at least is definitely gone.

Slip lockup is the intentional slipping of the torque converter in urban driving between 50 and 200 rpm or so. This means it's not fully locked, nor is it fully unlocked. In manual transmissions terms it's like pressing the clutch slightly while driving(or resting your foot on the clutch pedal). If it's bad for a manual it's sure as hell bad for an auto.

In automatic transmissions an issue you would see with a worn torque converter(in Volvos especially) is the RPM oscillating, jumping up and down by 50-200rpm in city driving(like cruising) but usually no such symptom above 50-60mph(when torque converter is fully locked).

[abscate]

I’m not exactly sure how a torque converter clutch works. Is it a friction disc like a msnusl or a fluid clutch of some kind? If it’s fluid, slipping won’t be bad for longevity

[dikidera]

There is a frictional disc, it's metal surface of some sort. Fluid(pressure) is applied on the clutch, pushing against the metal surface(the equivalent of say the flywheel).