Precedent won't run when batteries are full

[WalterM6]

The only clue I see in all this writing is. " sometimes it might jump but then thats it." To me that means the solenoid is not making contact and it's trying to run through the pre-charge resistor.

[Jmt553]

Originally Posted by Sergio

Unfortunately things are a little more complex in the Precedent and there is a proper sequence that needs to take place before the Controller will activate the Solenoid.

Tow/Run and Key switch need to be ON and FNR needs to be in F or R.

The micro-switch inside the MCOR (pedal) needs to close.

The voltage signal from the MCOR needs to be above a certain level (pedal pressed).

If all that happens in that sequence, the Controller completes the solenoid coil circuit to the negative side.

If the Solenoid fails to close, there should have been a "fault code" logged in the Controller memory and the shop should have seen it.

Pressing the pedal several times can sometimes help (temporarily) with either the micro-switch or signal track of the MCOR.

While the OBC does disable the Controller when the charger is plugged, it also prevents the reverse buzzer from making any sounds, so since you can hear the buzzer when the cart is not working, it is not an OBC issue.

First 6 of SN is PQ0843. Now that I’m home, the cart still won’t move. Tried pumping the pedal 30 times, still nothing. The only thing it managed to do was make a faint click and I could hear that high pitched noise it makes when the electric motor tries to engage. Another random try, the cart attempted to drive forward MAYBE 1 inch and then power was again cut. Is there a way to post a short video?

[Jmt553]

Since I’m out here messing around on it....i pressed the pedal and it acted like it was going to go then power was cut and then suddenly it lurched foward like normal and about threw me off the thing. What gives?! I just put a meter on the batteries, they are at about 12.6 volts each and 51.1 volts total.

[Raystar57]

Originally Posted by Jmt553

Since I’m out here messing around on it....i pressed the pedal and it acted like it was going to go then power was cut and then suddenly it lurched foward like normal and about threw me off the thing. What gives?! I just put a meter on the batteries, they are at about 12.6 volts each and 51.1 volts total.

While you are diagnosing this erratic problem please put the cart on jacks stands for safety!

The experts here will help you, I am far from that.
Just want you to be safe!

This could be some intermittent thing in a connector or wiring harness sonic weld issue.

MCOR could be a problem and I would have thought the solenoid also but that seems to not be the case at this point.

Batteries appear to be be good.

[Sergio]

The small movement caused by "filter capacitors" discharging (no solenoid closure) is a Series drive symptom, not Sepex.

You may have a Controller issue.

When the cart "looses power" does it coast freely or "beeps" until stopped?

The times you said you had to "push home" or load in the trailer, did the cart just roll or You had to put in Tow to overcome the "walk away brake"?

Depending on the answers above You can run some tests on the MCOR output, but beyond that it will involve getting into the Controller area which is not a lot of fun in your 2008.5 Precedent (electronics behind the battery).

[Jmt553]

During the time that it looses power it doesn’t coast but uses the motor to brake and it beeps. When I pushed it home I had to put it in tow

[Sergio]

That sounds like a Solenoid drop-out, but it should have definitely shown on the fault history log when the dealer accessed the controller.

Assuming the key switch was indeed defective, there is a good possibility the solenoid contacts were damaged if the Solenoid coil lost power while under heavy load.

There are other possibilities like HPD (High Pedal Detect) caused by signals from the MCOR bouncing out of sequence or SRO (Static Return to OFF) caused by they key switch power circuit (not just the key switch itself), but it does not seem it would have the prolonged OFF behaviour You are experiencing.

I would personally replace the Solenoid first with a heavier duty version that could be used on a future controller upgrade.

[Jmt553]

Thanks Sergio! I called Mech and he agreed that would be a reasonable thing to do at this point. Do you know of a good video or other literature you’d recommend that I can follow?

[Sergio]

This image shows You where the Solenoid is located on the electronics Module (click for bigger view):


The best way to get access to work on that is to remove the center batteries and drop the electronics module into the battery compartment.

The Solenoid is part #5:

One thing You can try now that is easier is to eliminate the HPD fault possibility caused by a defective MCOR micro-switch.

Access the MCOR by removing the floor mat, just take the 2 torx screws off each side of the trim that holds the floor mat and pull the floor mat off.

Remove the plastic access cover #7 in the image below:



Disconnect the 2-pin plug from the MCOR (#12) and place a large paper clip jumping the 2 pins on the harness connector.

Put some electric tape on the connection to make sure it will not short against anything.

That by-passes the pedal micro-switch and provides a consistent signal in case that switch is failing, although that should have also shown as a fault code on the controller log.

This is a video I found from one of the site sponsors, it may help:

http://www.youtube.com/watch?v=F93alt_pUuc

http://www.youtube.com/watch?v=F93alt_pUuc

[Jmt553]

now, if i do that test for the HPD fault and flip the switch from TOW to RUN and from N to Fwd, will the cart automatically take off or does it still require the pedal to be pressed?