Legacy SD45 not responding to Bluetooth Direction Commands

Well, you are getting a massive warning sign (blinking cab light) that indicates a stalled drive motor. You MUST drop track power for a few seconds in order to reset this warning and locked out motor drive state.

It's this simple. In RECENT Legacy and Lionchief Plus 2.0 engine using the LCP2 series of boards have stall detection in the servo feedback drive of the main motor. You command an RPM or speed and the motor and tachometer must achieve this speed. If it cannot do that in a certain timeout it thinks or assumes locked motor.

So, check the obvious:

#1 You have a FULL 18V and decent enough power supply on the track.

#2 the gears are not jammed or binding. This is checked by rotating the motor flywheel since these trucks are not typically backdriveable gears (meaning you can turn the wheels by hand and it spins the motor).

Again, once you get the cab blink, you are in a LOCKED state and MUST cycle power.

Where we have seen this is that older models of Legacy did not have this all detection in the motor driver. The thing is, any cruise equipped engine is trying to maintain a given RPM. In order to do that, there is a tachometer on the motor feeding back that information to the motor driver. When the motor speed is slower than commanded speed, the voltage ramps up to the motor trying to make it catch up. However, if say there is too much load, gears are jammed, then the voltage and thus the current to the motor can overheat it. In recognition of this, the newest firmware as loaded into recent 21 and 22 catalog year Legacy using the newer LCP2 electronics has this stall detection to prevent motor or the control board from this runaway condition.

That said, users can accidentally invoke this stall sensing when track voltage is low and yet via bluetooth a faster speed is commanded. This then invokes the safety lockout.

Again, when running in command mode using Bluetooth, universal remote, or TMCC/Legacy, these new engines do not like low or sagging track voltage and can invoke the safety.

Put another way- NEW Legacy (especially 2022 models) are different and respond differently than even slightly older Legacy using RCMC electronics. Apparently users have gotten away with in the past low track voltage and other details and since the older system did not flag this as a safety condition error. This causes them grief when the new engine warns them and they don't understand the problem.

Page 43 of the manual covers this https://www.lionelsupport.com/...d-NonPwd%20Units.pdf

Again, just to cover all bases. You said you ran the engine in conventional. So, from that, we believe the engine is not mechanically jammed or binding. Yes, under conventional the voltage would vary but, that same voltage is what determines the commanded speed, so it's less likely to invoke the safety condition for locked motor and thus cab light blinking.

However, any command mode operation- bluetooth, TMCC, or Legacy, the engine assumes and expects to have plenty of source voltage headroom for the motor to be able to achieve the commanded speed under load. And this is where users can get tripped up. Either just from old engines not complaining in this state or the user just unaware of how and why this could get invoked. The manual warns about too high of voltage (anything over 19V) but doesn't warn users that too low of track voltage or power loss, dips, bad track, could invoke the safety when running in any of the forms of command mode.

@Vernon Barry posted:

Put another way- NEW Legacy (especially 2022 models) are different and respond differently than even slightly older Legacy using RCMC electronics. Apparently users have gotten away with in the past low track voltage and other details and since the older system did not flag this as a safety condition error. This causes them grief when the new engine warns them and they don't understand the problem.

Early Legacy had a limited sensing capability, if the RCMC didn't see the drive motor matching the command speed for a specified period, it would shut down the motor drive.  You'd see that with a total sensor failure, or just unplug the sensor from the board.  The engine will take off for a few feet and then stop.

It's not like the old TMCC Odyssey I that would just take off at full speed until you killed the power or it flew off the tracks!

Nowadays, pretty much all of the RCMC equipped Legacy models had drive motor sensing.  Just a couple of examples, but I can assure you all, or at least most of the RCMC equipped engines have drive motor sensing, look at any later Legacy User's Manual.

The Legacy U28C from 2011.

The Vision Line Big Boy from 2014.

The H-10 from 2018

Thank you everyone for your input, especially Vernon.  The problem was that he had less than 18 volts to the track.  Once power was set at 18 volts, the loco's worked perfectly.

Thanks again!

Stu