2002 PDS ITS Question (Inductive Speed Control)

[JohnnieB]

Going from 40V+ down to 37.6V in a matter of minutes tells me you've got bad batteries.

Monitor the battery pack voltage under load.
What is pack voltage when controller goes into under-volt alarm?

[MauiHoss]

Good question -- I'll check the batteries under load. Last I checked the pack at static was reading above 37V. The charge gauge has been giving erratic readings but the DVM is very consistently showing above 37V. Batteries were installed new in 9/2008 and have been well maintained throughout their service.

I adjusted the ITS so that the plunger rod is 7/32" from the induction unit. This was as per spec from the PDS manual (page F-21).

Put the positive lead from the DVM on the white wire of the ITS and negative lead on the black wire. At rest, the reading was 11.32V. By the time the solenoid engaged it was reading about 10.88-10.9V. The controller displays the 6 flashes at about 8V -- near 3/4 of pedal travel. Pedal to the floor reads 3.5V. It's moving in the right direction but is out of spec with what you mentioned earlier: 10V at solenoid click down to 6V floored.

I found one of JohnieB's posts that included the following text:

Connect a DVM between the B- and M- terminals on controller.
Key ON F/R in either F or R
Press Throttle Pedal until solenoid clicks.
If solenoid doesn't click, we need to troubleshoot the solenoid activation circuit before proceeding.

If it does click, the voltage between B- and M- should be full battery pack voltage. (Pack voltage should be above 37.5V for troubleshooting)

If you have the full pack voltage there, slowly press throttle to floor.
Voltage should smoothly decrease to Zero.

If not, check ITS (Throttle) input to controller.
If it is good, controller is bad.

With DVM connected between B- and M- on controller showed 37V at rest. As the pedal is depressed the voltage goes wildly high. Maybe this test doesn't apply to the AllTrax DCX400PDS.

While still not right, I'm pleased to be making progress. Couldn't have gotten this far without ya'll!

[JohnnieB]

The batteries have been installed for nearly 5 years, so they are near the end of their usable lifespan.
Granted, there are a lot of variables that affect battery lifespan, but the controller is going into an under-volt mode, so either the pack voltage under load is dropping below the under voltage set-point, or the high current cables/contacts/connections are bad, or the controller is sick.

There may be some other problems, but the under-voltage issue is the one to fix first. In fact, the others may even go away when the controller is happy about the voltage it is being fed.

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As for measuring the voltage between B- and M- terminals on the controller.
To the best of my knowledge, it applies to all DC traction motor controllers. (Golf carts, fork lifts, people movers, etc)

The control element (Thingy that controls the amount of electrical energy going to the motor) is located between those two terminals.
(M- may be called by other names. IE: M- is labeled A1 on PDS controllers)
When the controller is powered up and everything is ready to go (Pedal pushed just far enough for solenoid to click), no electrical energy is being sent to the motor, so the entire battery pack voltage should be measured across the control element.

When the pedal is pushed further, the throttle tells the control element to pass some electrical energy to the motor, so the battery pack voltage is proportionally split between the control element and motor.

When the pedal is on the floor, the throttle should be tell the control element to pass all available electrical energy to the motor and the voltage across it will be -0-, or very close to it. (With a DCX400, the will be 0.1V per 100A of current flow through the control element, so the wide open voltage across the control element could be about 0.4V)

The voltage between B- and M- going "wildly high" as the pedal is depressed is weird.
It should not go higher than whatever the pack voltage is at that moment.

If you have an auto-ranging DVM, check the units of measurement when it is reading wildly high. It may be reading Milli-volts rather than Volts.
(I've been caught a few times by auto-ranging meters. )

[MauiHoss]

Right again JohnnieB -- seems the batteries are tired. Started with 36+V and that went below 27V as the pedal was pressed further to the floor causing the under-voltage error code on the AllTrax. I see from another post that ScottyB sets the under-voltage parameter at 27V prior to shipping.

I saw another of your posts on batteries. You are so helpful! The chart comparing different battery brands/models was very eye-opening. I had no idea that there were so many options for batteries. Our Interstate dealer supplies everyone on the island of Maui. My current Interstates are U2200UT. Checking Interstate's web site they have changed their numbering scheme so I'll need to figure out the best option for the DCX400PDS. ScottyB's digital battery gauge seems like an important option to keep track of the state of charge.

Well, until I get new batteries, I think were done here. Guess I'll start working on our 1989 EZGO passenger carrier now.

[MauiHoss]

It Works!

Dropped six new batteries in this morning and she's running like never before. It was a short first ride to the charger station for battery conditioning. The performance improvement was quite apparent even for that first ride. Can't wait to play a bit.

Also checked the oil in the differential since I had it up on jack stands. There was less than a tablespoon of oil in the pan! Cleaned and painted the differential pan, applied gasket maker and filled with 10oz of 30W before re-installing. One more job done.

The new DVM from Cart's Unlimited is due to arrive tomorrow so I can keep a close eye on the state of charge in the future.

Many thanks to all who helped and all who've posted such a trove of good advice.

[wallawil]

I have a 09 pds cart that flood waters made it up to the bottom of controller(not to connections). The ITS box was flooded. On diagnostic test it was giving a 2-3 code then started beeping erratically up to 6 beeps straight. Any suggestions?

[JohnnieB]

Originally Posted by wallawil

I have a 09 pds cart that flood waters made it up to the bottom of controller(not to connections). The ITS box was flooded. On diagnostic test it was giving a 2-3 code then started beeping erratically up to 6 beeps straight. Any suggestions?

Welcome to BGW!

You ought to start a new thread rather than hijacking an old one, but use a hair dryer to dry out the pedal box (pedal switch and ITS sensor) and the controller.

Also, disconnect all the plugs on the controller and clean them with contact cleaner.

Be sure to flip Run/Tow switch to Tow before disconnecting or reconnecting anything.