[Artie]

Hello, I'm playing with this little 2009 Miles truck that I just picked up from the auction with just 1200 miles on the odometer.

It came complete with no evidence of someone tampering with it, however I cannot get it moving.
The 6 Powersonic 12V 150Ah batteries were all low at 1.5-2V each, however after taking them off and charging them on 6 regular car 6A chargers for 72 hours, the pack seems to have come back to life, and now when reinstalled shows 78V. I doubt they will last but at least should move the car around the yard for a bit.

The problem is, the Curtis 1238-6501 controller blinks out error code 52.

After removing the 35-pin connector and spraying it with electrical cleaner, the Curtis came back to life a few times - the LED was flashing yellow, indicating normal operation, and the main contactor would loudly close, providing 78V between the B+ and B-. The car still won't move though. I verified the TPS was good, as the voltage gradually raises between 0.2-4V while I'm pressing on it. The "D" and "R" indicators light up on the cluster as I flip the forward/reverse switch. The voltage for D and R signals comes to the controller as well.

However I was only lucky for half a day, and now I'm unable to turn it on at all. It just keeps blinking the code 52. I thought of a bad connection in the connector, but wiggling and spraying does not help anymore. All pins are good.
According to the Curtis manual, code 52 is a OEM (Miles) spec code, and the only info I found online is that it means "open coil on main contactor or broken wire".

From what I read online, almost everything breaks on these trucks. What would be my next step in troubleshooting the thing?

 

[rmay635703]

It's best to reprogram the controller to remove any safety interlocks.

Wire any grounds to the battery ground itself

Replace the contactor or hardwire

Rewire anything around the steering column, bad connections abound.

There are a few commercial guys that work on these best to find one on the milesevowners group

Examine the motor if the issue continues after getting the wiring straight.

 

[Artie]

Code 52 was due to a bad pin that sends power to the main contactor. Fixed that.
Now, no codes, we have orange light indicating normal operation. Curtis gets 72V but still no vehicle movement. TPS works fine, Bypassed the Charge Door and Handbrake relays with a piece of wire. Forward/reverse switch now gets +12V. Pins 22 and 33 receive +12V when in F or R respectively.
Between U,V,W and B-, on all three leads we have ~36V, which don't change at all with the throttle applied.
Car won't move an inch.

Opened up the controller, tested the main components and didn't find anything suspicious. Read both Miles troubleshooting and Curtis 130-page manuals. I'm not sure what else to check. Ordered the Curtis scan tool on eBay hoping it will give me some new information.

 

[rmay635703]

Does the main contactor have any "resistance "?

Should be able to check with an ohm meter

 

[Artie]

Does the main contactor have any "resistance "?
Should be able to check with an ohm meter

I don't think contactor is a problem at all. It's just a relay and it works well.

 

[rmay635703]

My 1981 Comutacar had a very clicky FR contactor, sounded great but when the car wouldn't go I hardwired it and everything worked great.

Last step would be to bench test the motor and controller

If the motor won't spin on a bench when the controller is hard wired to it you have your answer.

Those trucks are known to have motor issues.

 

[Artie]

Any practical suggestions how to bench-test the controller or 3-phase AC induction brushless motor?

Right now I'm thinking the controller is dead due to U,V and W voltages not changing at all with the throttle applied. I think at least they should fluctuate a bit, but I may be wrong.

 

[Artie]

Today I received the basic (really functionally challenged one) user level Curtis programmer. It shows fluctuating Pot values, but throttle always stays at 0%. Also, parameter Interlock=ON. I think that's the culprit. I checked and I do have 12V at pin 9 any time the throttle is pressed. Car won't move.

 

[Artie]

I guess I figured it out, purely by accident. All that Curtis controlled needed was a press on the brake pedal before the car would respond to the throttle. It was just programmed this way, and of course the owner's manual doesn't say anything about that. Now it runs & drives perfect!