User avatar
hgoudey
Forum Supporter
Posts: 55
Joined: Fri Jul 08, 2011 6:39 pm
Delivery Date: 03 Jul 2011
Leaf Number: 5132
Location: El Cerrito, CA

clearing P0AA1 positive contactor error - resolved

Sat Feb 25, 2017 3:54 pm

Updated - 3/15/2017 Jim Pollock (Turbo3) of LeafSpy discovered the CAN procedure to clear the P0AA1 contactor code that otherwise requires Consult III+. Clearing this code will be a feature added to future versions of LeafSpy Pro, but you can contact Jim for help if you have this problem in the meantime

Original post below:

I have a complete 2013 Leaf drive train that I removed from a crashed vehicle. I am trying to get it operational to put into an EV conversion.

It currently has a persistent code P0AA1 (positive contactor), an indication of high voltage on the switched side of the relay when the car doesn't expect it. This can be a stuck contactor or perhaps the result of someone hacking a high voltage connection improperly (I did not do this, but a previous owner may have).

I have tested the operation of the contactors (including pre-charge) and the pre-charge resistor is good (30 Ohms), so I don't see any obvious reasons why it shouldn't be able to close the contactors, and there is no high voltage on the wrong side of the contactor at present.

I have tried resetting the code using Leaf Spy, but it is persistent even though the fault condition that throws it is not currently present. The manual says P0AA1 requires "specific DTC clear" under "work support" in Consult. Is it possible that Leaf Spy doesn't support this level of reset?

Any thoughts on other causes of this particular error that would prevent the controller from attempting to close the contactors? I'm pretty sure the high voltage interlock circuit is satisfied (at least it doesn't show those error codes and all the connections are made).

It will shift between park and neutral , but not drive or reverse. The ABS and airbag controls are not present, but everything else is.
Last edited by hgoudey on Wed Mar 15, 2017 4:15 pm, edited 2 times in total.

arnis
Posts: 743
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: clearing P0AA1 positive contactor error

Sun Feb 26, 2017 2:38 am

Theoretically it is reasonable to have DTC code that can not be deleted easily with normal "scanner tool"
after crash. BMW also has something similar if airbags have been deployed.

Also if crash happened with drivetrain under load that might possibly degraded the contactor itself.
Usually contactor disconnects with no load. But in crash situation it should disconnect in all situations,
including full throttle. Depends how was the system engineered. If it did disconnect under load there
might be soot on the contacts (spark).

How did you measure is there HV on the positive side? Where did you put the negative lead?
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

User avatar
hgoudey
Forum Supporter
Posts: 55
Joined: Fri Jul 08, 2011 6:39 pm
Delivery Date: 03 Jul 2011
Leaf Number: 5132
Location: El Cerrito, CA

Re: clearing P0AA1 positive contactor error

Sun Feb 26, 2017 9:33 am

Thanks for the reply arnis. To clarify, I never measured high voltage on the switched side of the contactors, but I have measured 372V on the battery side of the contactors (the battery pack is out of the car with the lid off but still assembled as original). I have removed all the other components and wiring harnesses from the car and reassembled them loose on the floor, but the problem is identical to what I encountered when it was still assembled in the car. The code (P0AA1) indicating high voltage on the switched side of the contactor (when it shouldn't be) is my only indication of this error. I never did anything to the car that would have caused this condition.

However, I bought it from a company that had acquired this crashed Leaf for testing a vehicle to grid system they were developing, so they may have made an improper high voltage connection that resulted in this condition. Ultimately, the high voltage connections they made (that I saw because the wires were still in place) were on the battery side of the contactors, so they could charge and discharge the battery without the contactors being closed. They may have resorted to this connection after causing this contactor error that prevented them from accessing the battery by turning the car on and closing the contactors.

I have tested the three contactors separately from the rest of the components by applying 12VDC to the coils and listening to them click. They seemed to operate normally, but I will go back and check the resistance between the high voltage terminals when closed based on your thought about arc damage (I have some other Leaf contactors to compare them to). I know the contactors are not stuck closed because I have manually switched all of them. and I know I never measured high voltage on the switched side when the battery voltage was present on the battery side.

As for the crash itself, it was a roll-over that deployed only the driver's steering wheel airbag. None of the other airbags deployed. The car had 16k miles on it at the time and the battery currently reports 92% health status using Leaf Spy.

User avatar
hgoudey
Forum Supporter
Posts: 55
Joined: Fri Jul 08, 2011 6:39 pm
Delivery Date: 03 Jul 2011
Leaf Number: 5132
Location: El Cerrito, CA

Re: clearing P0AA1 positive contactor error - resolved

Wed Mar 15, 2017 4:21 pm

Many thanks to the awesome work of Jim Pollock (Turbo3) and creator of LeafSpy. He was able to determine the procedure to clear the P0AA1 code that was preventing my contactor from closing.

This is an error that is likely to be encountered by folks hacking additional batteries or a vehicle to grid connection to their Leaf. If you make the mistake of applying high voltage to the switched side of the contactor when the car does not expect it to be closed, this hard error will be triggered and the regular LeafSpy DTC clear function will not clear it.

Jim is going to add the P0AA1 clear to future versions of Leaf Spy, but in the meantime if you have this problem you can contact him for help to get it cleared.

Samito
Posts: 2
Joined: Sun Apr 02, 2017 1:12 pm
Delivery Date: 12 Feb 2017

Re: clearing P0AA1 positive contactor error - resolved

Sun Apr 02, 2017 1:22 pm

Excuse me, i just bought my nissan leaf 2013 S yesterday. And today i couldn't start it, when i checked it on leaf spy pro it gave the same code you were talking about.
Can you please tell me how to solve thus issue.

Thank you

User avatar
hgoudey
Forum Supporter
Posts: 55
Joined: Fri Jul 08, 2011 6:39 pm
Delivery Date: 03 Jul 2011
Leaf Number: 5132
Location: El Cerrito, CA

Re: clearing P0AA1 positive contactor error - resolved

Sun Apr 02, 2017 7:55 pm

Jim Pollock (Turbo3 on this forum), who created LeafSpy, has determined the special routine to clear the P0AA1 contactor code. He plans to add it to LeafSpy Pro in the future, but for now you can contact him directly (either PM the account I just mentioned, or use the email that is listed in Leafspy Pro help).

You should refer to the Service manual on the P0AA1 topic (EVC section , page 174 in 2013 service manual available online) and confirm that there aren't damaged parts before clearing the code. Some People have reported burning out the pre-charge resistor when they applied HV that caused this code (in the process of hacking a supplementary battery pack).

I bought a crashed Leaf from a company that was using it for vehicle to grid testing. They had caused this code to appear by applying external HV when the contactor was open. I tested all the contactors and the resistor and confirmed they were normal before using the special code clearing software written by Jim. Everything worked again after that. I have removed the entire drive train, battery and wiring harness from the crashed car and I now have it operating in an EV conversion of a 1967 Volvo P1800.

Return to “Engineering”