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Zilla Error code 1131 short/load at precharge

4571 Views 3 Replies 2 Participants Last post by  92 Escort EV
While my wife was driving my 92 Escort conversion it "died". It started normally drove for about 1/2 mile and the dash indicator that the car is ready to drive went out. See

I pulled the codes from the hairball using the palm pilot to find:
*1131 - Shorted / Loaded Controller during precharge
*1221 - Major Overspeed of Motor Beyond X (set at 7000rpm - I don't think this happened, my wife and daughter said nothing sounded odd. I have only had the motor up to 6000 rpm once and you can hear the motor sounding different than at 4000 or less.)
*1133 - Lost Communication with controller during use, either direction.
*1124 - Main Contactor stuck on (The contactor is not burnt, will close if 12 volts is applied to coil with the main battery off/breaker open)
*1231 - Propulsion pack open, no contactor drop, and controller is not responding. (When my wife called me I had her turn the battery pack breaker off).

We pushed it home and cleared the codes. Now only the 1131 code remains, (Shorted / Loaded Controller during precharge). When the key is turned to the start position the precharge light comes on at the hairball but goes out when the key is released. The main contactor does not close.

I have not looked at the codes in the hairball since adding the valet mode parameters about 6 months ago and I did change out the clutch during that time which may affect why some of the codes are there. Batteries were disconnected and the speed sensor were removed/installed during the clutch install.

There are no blown fuses anywhere and no wires are shorted or burned. There was no excessive heat, no smoke and no burning smell under the hood or in the electrical box housing the controller and hairball.

I assume that the Zilla is protecting itself by not closing the main contactor, (That is why I opened the battery pack breaker before I tested the contactor coil).

Anyone with experience with this, or suggestions on where to start checking would be appreciated.

In the mean time I will contact the KTA where I purchased the controller and I'll drop a line to Cafe Electric also.
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· Registered
15 Posts
Discussion Starter · #2 ·
Just an update:

I sent E-mails to KTA and Cafe Electric, and got a reply from both. I'll keep you posted as to how things work out, but with help from Otmar, I am diagnosing the problem now.

It turns out that the 1221 "motor overspeed" is a false error from any error code that happens while driving, and the 1124 "main contactor stuck on" is a bug in the code.

I want to let everyone know that Cafe Electric is still standing behind its controllers, and helping its customers. Keep in mind that Otmar was impressed that I did a good job of troubleshooting on my own, and sending a clear E-mail.

Ill keep you posted.

· Registered
56 Posts
I had similar problem, and Otmar diagnosed quickly as a faulty power to the hairball. Turns out I get the problem when a big bump jiggles the fuse pack and momentary disconnects the power to the zilla. Cleaning the fuses solves the problem.

· Registered
15 Posts
Discussion Starter · #4 · (Edited)
Here is the diagnostic outcome with the problem I had with my EV.

It seems that possibly, at some point there was a short in the speed sensor wire that caused damage to the Hairball, (the hairball is the interface to the Zilla controller). I may have done this while changing my clutch. It is not severe damage and was sent back to be repaired, ($25 Plus shipping).

(Note: If you are interested in the ceramic clutch disc I installed send me a message to start a new thread, this should stay on topic for Zilla errors!)


Update on 8-10-2009

Put a fuse in the speed sensor 12V line!!! (I should have known this:()

I had a speed sensor wire rubbing and eventually shorting to ground on my EV, that caused damage to the hairball, (my fault for removing a fuse!). The reason I removed it was that it was an inline fuse and very close to an AC inverter. I thought it might be introducing noise into the speed sensor, causing the 1141 error. I replaced it with the original shielded cable that had no fuse in the 12V wire. (I know, Bad, Bad!!!)
The speed sensor only uses 10mA to run so, an appropriate fuse size will protect the Hairball from damage. I removed the speed sensor 12volt wire from the hairball. It now gets its power from a separate 12V source from the hairball. (In other words don’t use the Acc +14V Out on the hairball). With no fuse in the wire, the short to ground caused damage to the hairball that had to be sent in for repair. This was my fault, but can’t happen now that the power is not from the hairball, and now has a permanent fuse. I was also originally using a blade style fuse, and they only go as low as 1Amp. You may need to use a glass fuse that is about 62mA.

(The dash lights likely were not the problem, but I will leave the information here.)
I now believe that the dash lights that I had connected to the instrument panel may have been feeding back Pos 12 volt power to the hairball. Also problems in my wiring also may have been keeping the key input powered (at about 8 volts). The dash lights problem could have been prevented with diodes to prevent feedback, and I have changed the key on input to the actual original ignition on circuit. Originally I was using an electric fan circuit that seemed to be only hot with the key on.
I have not reconnected the dash lights since reinstalling the repaired hairball and have not had a repeat of the 1131 error. This actually happened to me 2 times, (yes two repairs), until I corrected my wiring errors.


1231 Error – Propulsion pack open, no contactor drop, and controller is not responding
Not a problem, just the fact that I had my wife turn off the breaker for the battery pack when she called me with a problem with the car.

1133 Error – Lost Communication with controller during use, either direction
This could be a problem but probably just loss of power in my case. It is not a common error to see.

1221 - Major Overspeed of Motor Beyond X
This is common and happens when any error code happens while driving.

1124 - Main Contactor stuck on
This is an occasional code that appears due to a bug in the code.

1131 - Shorted / Loaded Controller during precharge

There are two possible problems for this:

Possible Cause#1
The Hairball thinks it is initiating a precharge, but due to some problem is not actually precharging.
The most common cause for #1 is from a internal failure due to a overload (shorting) of the power supply to the speed sensor which is internally related to the precharge relay. Check the voltage on the Acc +14V Out pin near the speed sensor input. It should be within 0.5V of your 12V power in. A common failed indication is 3-6V. Usually this happens even with the key off, but if it reads good, make sure it stays good during precharge.
(If readings are not within 0.5V of each other contact your dealer)
(If the readings are within 0.5V of each other continue below)

The second most common cause for #1.
Listen for a click of the precharge relay inside the Hairball while trying to start. It should click, and the red prechaging LED should come on bright.
(If there is no click or the LED is not on or not as bright as it should be, like the error LED, contact your dealer)
(If there is a click and the LED is on and is as bright as it should be, like the error LED, go to Possible Cause #2)


Possible Cause #2:
The controller has a internal or external load on the battery terminals that is keeping it from being precharged during the startup sequence.
Make sure there are no shorted connections at the controller, (wires making contact where they shouldn’t). Measure the voltage on B+ and B- of the controller while trying to precharge. The voltage on the controller should rise. If the voltage on the controller does not rise, then connect a 120V light bulb from the Controller positive to the Battery positive to override the Hairball precharger. If the bulb stays lighted, it verifies that the controller is loaded, and that it's not a failure of the precharge circuit itself.
(If the controller is loaded, 120V light stays on, disconnect all wires from the controller and contact your dealer)

I hope these trouble shooting tips may help others in the future.
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