2010 Stuttering RXV

nickdalzell1

Danahars i thought i had licked but apparently not.

2010 Freedom RXV came in with a solenoid clicking, as if it were not totally engaging (think car battery died, rapid clicking) and it had one of those tiny hardwired solenoids i thought were unique to the 2008.


After replacing it it powered up fine, and the handheld (i have the Danahar handheld) hooked up i did some diagnostics and wanted to see what errors were thrown recently. I saw quite a few scary ones i normally do not see.

AC Short Circuit
Heat Sink Temp High
DC Bus High--most recent as in same hours as the car is currently reading

Tried to drive it after verifying the batteries tested fine, they are 2018 Trojans.

Car made it just up the road and just shut down, almost throwing me off (has a factory volt gauge, which showed full but during shutdown went straight to zero.


Thought brake failed, but switched off and back to forward, it powers on, as normal, but then it stutters, like motor is trying to go forward and reverse at the same time, similar to how they act when the speed sensor goes bad but this one predates that sensor. I had to put it in tow and push it back. now handheld shows 'SOFTWARE UNKNOWN!' and refuses to read the controller, or shows the menu but every entry shows FAILED TO READ!'


Suspected failed controller from previous errors plus that failed solenoid possibly corrupting data, but rebuilt did the same thing only now the handheld won't even turn on. gets to EZGO and freezes.


Then, like magic, it fixes itself and runs fine. shows zero errors and reads everything normal. I don't believe in magic, and while test drives seem ok, why it acted exactly like it did before and now runs normal i am confused. i will keep driving it but not sure if the old controller is bad now.

I have checked all battery cables, brake, key switch, load tested each battery while in tow, double and triple checked every bolt and wire going into controller.

The new controller came from FSIP. now the car runs but i'm not convinced it will stay fixed. Handheld now reads like nothing is wrong, not even set any code in history during the first drive where it stuttered like the old controller did. During that first drive, however, handheld wouldn't read jack.

BGW

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WalterM6

Basically the same thing happened to me the other day. I couldn't communicate with the controller. Here's what I would do. Get a can of CRC Electronics Spray Cleaner. Disconnect every connection in the path and spray clean them.

Attached Images

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nickdalzell1

we got tons of those cans, they have come through many times when a series TXT has a wonky F/R board, however, the fix is never permenant.

This car has a factory light/brake lamp kit, and a voltage reducer, which did make a big effing spark when i connected it to B+ main, while i was in tow, it might have confused the new controller, but unsure. i still cannot make it fail again. drove it 5 miles up the road no issue.

BobBoyce

I would suspect one or more failing FETs in one or more of the three H-Bridge (AC version of the motor output) assemblies. Causing a short of the AC output as it is generated. It could also be in the motor, if it has been overheated too many times. From the strange fault condition, seems more likely the controller. Don't know why the replacement failed initially, unless the batteries drained from the short earlier.

nickdalzell1

It was heat sink temp high not motor temp high. AC short circuit was 2.5 vehicle hours earlier.

It still hasn't failed and we had others riding it around. Could a loose tow plug cause this? The original controller would run fine but handheld would show no connection or software unknown and soon as it jittered and locked up the handheld would then show the menu but all fields were failed to read.

New controller didn't connect period, which has happened on some FSIP rebuilds, it never communicates for some reason, but it woke up and worked after that initial fault, did not even log the failure as if it never stored it, and still acted as if it were zero hours. no decimals nothing.

I still wonder if the reducer backfed it when it was connected, even though car was in tow.

The original controller read everything fine until it failed that one first time, then refused to read correctly, i noticed though the reading for vehicle hours was 1743.6 and after the fault, when i could read anything at all without getting failed to read, it had gone backwards to 1743.4, it had forgotten .2 hours.

BobBoyce

Heat sink temperature is controller heat sink. More evidence the short was internal to the controller. Yes, a bad connection under the cupholder can cause a read fault at the RXV handset. When in tow mode long term, controller logic is shut down and nothing should affect controller data. It should not be possible for the controllers internal clock to regress. It could have occured during a memory corruption. If you interrupt power during the first 5 seconds of switching the run/tow switch in either direction, it can corrupt memory in some controllers. This is because it initiates a mode change, and the controller needs to finish its shutdown housekeeping prior to losing power. The same at startup, it must load memory from where it was saved during the shutdown housekeeping. Not all controllers do this, only the more sophisticated ones. Older controllers with limited logic abilities did not need to do this.

nickdalzell1

It was odd. This being the original controller not the rebuild (which still works and reads properly).

The hours was 1743.6, which was the exact hour reading as the most recent fault in the history, DC Bus high--Software detected, which i am guessing is when the solenoid was clickety clickety. It would go ka click ka click very fast, as if dropping out, just as soon as the key was switched on.

After replacing the solenoid i had those faults in history--not active. Voltages read normal, i put car in tow, load tested each battery (even with 2018 i do not take chances) and verified cable integrity, etc. the SOC on the handheld then was 100%, 51.2V

Put in run, backed out of the shop, went to forward, made it 100 feet then it just shut down, like someone had switched the key off. It has one of those factory battery fuel gauges, analog, and it went straight to empty, and the red warning light came on. Switched key off, then back to fwd, and it would go 2 feet, slam, 2 feet, jitter, got worse the more gas pedal you used. it just shook like low voltage, even though the handheld, still connected, was showing 97% SOC, 50.4V.

Then the handheld said COMM ERROR and rebooted itself, then said CONNECTING....SOFTWARE UNKNOWN.

Second attempt, CONNECTING...NO CONNECTION! Cart ran again, and soon as the handheld showed a reboot and a menu, slam and jitter and not going anywhere. Each menu, be it DIAG REPORT or PERFORMANCE would show FAILED TO READ! as the value.

Put it in TOW, rolled it back in neutral, so the brake is obviously working fine. Back in the shop, still cannot read the damned thing, FAILED TO READ. When i was reading initially before trying to drive it, i had a hour reading of 1743.6, as that was also the last time the code for DC Bus high flagged itself.

Eventually many key cycles later it came on, but the FAULT HISTORY was blank, and the hour reading under BATTERY/WARRANTY was 1743.4. Literally .2 hours in the past. Still could not make it very far before it would jitter and shake and just not move anywhere, but i never got the shutdown/empty battery guage except that one first time.

Figured controller shot, the old solenoid clicking on/off and so on could not have been good to the memory, so i drug out a rebuild Danahar, which has its own new brake resistor controller mounted on the heat sink on the back, thus eliminating that issue too.

All installed, handheld would power up, display the EZGO logo, and....nothing. not CONNECTING or any error. just frozen at EZGO.

This had happened before regarding rebuilt Danahars, to where we now have FSIP program them for Freedom 19.5 MPH at their end before sending them to us. So i did not assume anything wrong. I was not getting FAILED TO READ or SOFTWARE UNKNOWN, just frozen at the EZGO logo.

Backed out of shop, again, and made it 500 feet this time, then it jittered all over the place until all momentum was gone and all you could do is make the motor jump. Back to TOW, rolled back inside, soon as i am inside i notice the handheld, still plugged in, showing the main menu (in TOW and Neutral, it still reads if possible). Thinking i had better see some fault for sure now, i look at the faults and fault history. blank. Hours reading 0.0, SOC at 95%, volts at 49.4V.

Back to RUN, take it for a drive, everything works fine. noting wrong, cannot reproduce the problem anymore. Your guess is as good as mine.