ITS problem?

[billbeach]

Originally Posted by JohnnieB

The ITS sensor is a proximity detector whose current (amperage) throughput varies with the relative proximity of the iron slug moved by the throttle pedal.

Attached is a schematic of what is inside the sensor.

Also attached is how to test the ITS circuit, two thirds of which is inside the PDS controller.

The ITS voltages are measured with the Negative Test lead attached to the main negative terminal of the battery pack.

FWIW: Measuring the voltage between the black and white wires is how to check the ITS circuit when an Alltrax Controller is installed - The same ITS sensor is used, but Alltrax powers it differently, probably to avoid Patent infringements. (The ITS patent document is also attached - it contains a theory of operation for the device.)

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The original voltages posted were within specs for a PDS controller. The voltage on Pin-4 is low when pedal is down, but the 15V +/-1V spec is with pedal up.

Also a bad ITS sensor isn't consistent with the symptoms stated in the first post of this thread.

Going a few feet and stopping is typically a solenoid not activating or a solenoid with bad contacts. Traveling further when pedal is only partially pressed is a further indication of a solenoid issue.

Basically, the charge placed on the filter capacitors via the pre-charge resistor has enough energy to move the cart a few feet, and if the charge had been replenished by the battery pack being directly connected via the solenoid contacts, the cart probably would have kept moving.

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Personally, I'd reconnect everything and measure the ITS voltages again as show in the troubleshooting tree with negative test lead attached to B- at battery pack.

I put it back together and the voltages for the ITS are within specs. JohnnieB, I think you are correct about this being a solenoid issue. I'm going to replace the solenoid and hope for the best. I will report the results after I have replaced and tested. Thanks to everyone for all the help,
Bill

[billbeach]

Originally Posted by billbeach

I put it back together and the voltages for the ITS are within specs. JohnnieB, I think you are correct about this being a solenoid issue. I'm going to replace the solenoid and hope for the best. I will report the results after I have replaced and tested. Thanks to everyone for all the help,
Bill

No joy in Mudville. Replaced the solenoid and the problem has not changed. When I moved the cart while testing it, I found strange looking parts where the golf cart had been parked. One of the pieces is like a nut and has threads. One side of it is covered with a soft material that has a small hole in it and seems to be for some sort sort of a detent. One of the pieces appears to be a round plastic piece that has broken. The other small pieces are part of a plastic strap that has hardened and crumbled into pieces. Any help identifying this part with the threads will be greatly appreciated. I have looked over all the parts explosion I can think of have been unable to find it.

[scottyb]

The booted nut is from the run/tow switch

[billbeach]

Originally Posted by scottyb

The booted nut is from the run/tow switch

THANKS! That is exactly what it is.

[billbeach]

Originally Posted by billbeach

I put it back together and the voltages for the ITS are within specs. JohnnieB, I think you are correct about this being a solenoid issue. I'm going to replace the solenoid and hope for the best. I will report the results after I have replaced and tested. Thanks to everyone for all the help,
Bill

Replacing the solenoid did not fix the problem. I fear this problem may remove what little sanity I have left. Review:

• Problem. When accelerator is pressed, cart starts to move forward and then grinds to a halt as if the brake was being pressed.
• ITS has tested good.
• Controller bench tested good.
• Solenoid has been replaced.

I'm starting to think that the Regen braking is causing the problem. Unfortunately, I can find no trouble shooting or wiring diagrams that shows how this feature is set up. Thanks a million for any help.

[JohnnieB]

Does beeper beep rapidly when it grinds to a halt?

If so, you might have a loose connection on on of the control wires to or from the keyswitch or the F/R switch.

If you try to change direction or shift to neutral, or turn the key off, while the cart is moving, the controller applies max regen braking and beeps the beeper.

An intermittent connection/contact in any of the five wires associated with those two switches, or in the switches themselves, will cause the same reaction from from the controller.

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Also, put controller into diagnostic mode and listen for the error codes.

Text at bottom attached label tells you how to get into diag mode.

[billbeach]

Originally Posted by JohnnieB

Does beeper beep rapidly when it grinds to a halt?

If so, you might have a loose connection on on of the control wires to or from the keyswitch or the F/R switch.

If you try to change direction or shift to neutral, or turn the key off, while the cart is moving, the controller applies max regen braking and beeps the beeper.

An intermittent connection/contact in any of the five wires associated with those two switches, or in the switches themselves, will cause the same reaction from from the controller.

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Also, put controller into diagnostic mode and listen for the error codes.

Text at bottom attached label tells you how to get into diag mode.

When I try to go forward, I can hear solenoid click but the rear wheels do not move and I do not hear any beeps. When I try to go in reverse, the rear wheels start to turn really slow and make a kind of clicking/grinding noise. Of course the beeper sounds because I am in reverse.

When I go into diagnostic mode, I get 4-0 beeps. I can't find a diagnostic code for this fault.

[JohnnieB]

The first set of beeps after going into diagnostic mode indicate which PDS mode the controller is in. 4 beeps = Freedom Mode.

If you didn't get any beeps after the initial set of four, the controller thinks it is working normally. However, the controller doesn't monitor for all possible malfunctions.

Connect your voltmeter between the M- and B+ terminals on the controller and try to drive cart.

You should get zero volts when the pedal is pushed just far enough for solenoid to click and the voltage should then smoothly increase to fully battery pack voltage as pedal is pushed to floor.

If not, the controller is bad. (The other option is the ITS is bad, but you've already said the ITS checked good.)

If the voltage does go to full battery voltage, the motor is bad (Brushes ?), or a bad cable to motor.
Check F1 & F2 cables for worn through insulation where they are routed around frame.

[billbeach]

Originally Posted by JohnnieB

The first set of beeps after going into diagnostic mode indicate which PDS mode the controller is in. 4 beeps = Freedom Mode.

If you didn't get any beeps after the initial set of four, the controller thinks it is working normally. However, the controller doesn't monitor for all possible malfunctions.

Connect your voltmeter between the M- and B+ terminals on the controller and try to drive cart.

You should get zero volts when the pedal is pushed just far enough for solenoid to click and the voltage should then smoothly increase to fully battery pack voltage as pedal is pushed to floor.

If not, the controller is bad. (The other option is the ITS is bad, but you've already said the ITS checked good.)

If the voltage does go to full battery voltage, the motor is bad (Brushes ?), or a bad cable to motor.
Check F1 & F2 cables for worn through insulation where they are routed around frame.

When I press the accelerator, the voltage varies from 0.0 to 2.x. So, I guess the controller is bad. I'll replace it and report results. Thanks so much for your help.

[billbeach]

Originally Posted by billbeach

When I press the accelerator, the voltage varies from 0.0 to 2.x. So, I guess the controller is bad. I'll replace it and report results. Thanks so much for your help.

Problem is finally fixed. Turns out a bad battery was the culprit. I was talking with someone who repairs golf carts about my problem and he ask if I had checked my batteries. I told him yes, I had checked each one with a volt meter. He told me that testing with a volt meter was not reliable. I need to check the specific gravity in each cell. I followed his advice and found a battery bad. I replaced it and the cart runs great again.

Thanks to everyone for the information and the kind suggestions.

Bill