Temperature problem?

[drpeshev]

I have a major problem with my Chevy Spark EV. After a small crash and repair (AND RESET all systems) now my spark won't start under 15oC (60F) temperature.If the temperature is over 15oC(60F) there is no problem.Under 15oC (60F) won't start and two errors in diagnostic: Powertain control module 2 error(HPCM2 error) and High voltage System Interlock Circuit low - P1E00 and P0A0C codes.I tried to lie the system with resistors in the ambient temperature sensor and manage to show permanent 18oC (65F) on dashboard , but no luck . I'm not in US and here , there is no Chevrolet dealership to ask for help.Please, help me if anybody have a clue

[Infinion]

I would definitely recommend getting yourself a service manual, find a used one in this forum or subscribe to an online service manual like alldatadiy.com.

Here is some details regarding P0A0C

DTC Descriptors

DTC P0A0C
High Voltage System Interlock Circuit Low Voltage

DTC P0A0D
High Voltage System Interlock Circuit High Voltage

Circuit/System Description

The high voltage interlock circuit is used to determine if access to high voltage components or connectors is being attempted. The opening of these high voltage components causes the high voltage interlock circuit to open. The hybrid/EV powertrain control module 2 sources about 5 V on the high voltage interlock circuit loop. When the hybrid/EV powertrain control module 2 detects a loss of high voltage interlock circuit current, the high voltage contactors are commanded open.

The high voltage interlock circuit monitors for integrity of the following components:

- F103 Power Inverter Module Assembly Case Cover

- S15 Manual Service Disconnect

- A4 Hybrid/EV Battery Pack high voltage harness connector X1

- A4 Hybrid/EV Battery Pack high voltage harness connector X2

Conditions for Setting the DTC

P0A0C

The hybrid/EV powertrain control module 2 detects high voltage interlock circuit 5 V low reference voltage is less than 30 % of the commanded 5 V signal voltage.

Action Taken When the DTC Sets

- DTCs P0A0C and P0A0D are Type A DTCs.

- The hybrid/EV powertrain control module 2 opens the high voltage contactors when vehicle speed is less than 5 km/h (3 mph).

Conditions for Clearing the DTC

DTCs P0A0C and P0A0D are Type A DTCs.

Diagnostic Aids

- Test for a fully engaged hybrid battery pack high voltage manual disconnect whenever an open or intermittent high voltage interlock circuit condition is observed. The hybrid battery pack high voltage manual disconnect lever must be pressed down fully in order to completely engage the high voltage interlock circuit terminals.

- The A4 Hybrid/EV Battery Pack high voltage connectors X1 and X2, the S15 Manual Service Disconnect and the F103 Power Inverter Module Assembly Case Cover must all be engaged to complete the interlock circuit loop.

- With all monitored high voltage components engaged and the High Voltage Interlock Circuit is Energized, observe the scan tool hybrid/EV powertrain control module 2 High Voltage Interlock Circuit Status parameter for a PASS status. To help identify intermittent conditions, manipulate the monitored components and inline connectors. An open interlock circuit will display a FAIL status.

Note:
An S15 Manual Service Disconnect that is not fully engaged may result in an intermittent DTC PA0C.

Vehicle OFF, disconnect the 12 V battery. Remove the S15 Manual Service Disconnect.

There is quite a bit more detail to the testing bit. Make sure if you verify the integrity of S15 or any of the high voltage interlock connectors, that the car is completely de-energized as they say.
There are more details regarding testing the interlock's components via resistance and visual inspection, but hopefully this gives you an idea on where to start. S15 in particular is under the rear seat cushions.

Again I recommend the service manual if you want to do the troubleshooting yourself. PM me and I can send you a discount code for alldataDIY. You will need to know how to use a multimeter, and it would be instrumental if you had a comprehensive diagnostic tool (or a mechanic friend with one) that you can plug into the OBD port in service mode to test the systems. If you aren't comfortable with doing resistance tests and poking probes into different connectors while the car is off, you might want to research a good electrical car technician (especially one familiar with EVs) in your area with the tools and comfort level to hire.

Lastly, I don't know the nature of the accident and affected areas, but the simplest interlock is under the hood. The plastic engine cover with chevy logo has a bolt that depresses a toggle switch to indicate if the cover has been removed. that could also prevent you from driving or cause intermittent issues. Rich Benoit shows that here https://youtu.be/1HeEK5cLNpw?t=143. Try inspecting yours.

[Infinion]

Here's a document regarding P0A0C

[drpeshev]

New error P0AA4 -EV battery negative contactor circuit stuck closed
Now the vehicle turns off when fast acceleration or brake is made
I'm desperate

[Infinion]

New error P0AA4 -EV battery negative contactor circuit stuck closed
Now the vehicle turns off when fast acceleration or brake is made
I'm desperate

I'm not sure about the exact details of the EV Component Limited Warranty, but it is an 8 year warranty that even a 2013 Spark EV should still have.
If you have an account with https://my.gm.com/chevrolet/en/warranty you should enter your VIN to see your warranty status.

Worst-case, the primary contactor in the front of the battery pack welded itself closed and you'll need to replace it OR (unlikely) the whole contactor assembly. Again I'm not sure what's covered, but this seems like one of those jobs GM could pay for.
Here's what that looks like in this ebay listing of OEM part # 24279022. Pay attention to those part numbers on the boxes.

Also for your information, here is an exerpt from the WeberAuto youtube channel where professor Kelly talks about the positive and negative contactors in the Volt. This is relevant because the Volt, Spark, and Bolt are all sharing the same high voltage control architecture
https://youtu.be/eWYtq0hxhQg?t=6161


Here is where the battery main contactor assembly is. They're the components in front of the batteries under the battery assembly cover. Not something you can easily get to I don't think.


Try and research if there are EV repair shops that you could contact to get this work done (this is also assuming that it is not a result of the previous code issues you first mentioned).

Have you had the opportunity to check the various high voltage interlock components mentioned earlier (the bolts for the plastic "engine" cover under the hood being one of them)?
Have you had the opportunity to disconnect the 12V battery's negative terminal (under the hood)?
Have you had the opportunity to access the high voltage service disconnect under the rear seat (after disconnecting 12V battery) and disconnect that as well?

Watch this video of Geddyz Budget LTD safely disconnecting power to a Spark EV
https://youtu.be/CFB0AKnV4uA

[drpeshev]

Where (the Hell) is this resistor
What is battery disconnect unit BDU (12v harness?)

[drpeshev]

Have you had the opportunity to check the various high voltage interlock components mentioned earlier (the bolts for the plastic "engine" cover under the hood being one of them)? Yes
Have you had the opportunity to disconnect the 12V battery's negative terminal (under the hood)? Yes
Have you had the opportunity to access the high voltage service disconnect under the rear seat (after disconnecting 12V battery) and disconnect that as well? Yes

[Infinion]

Where (the Hell) is this resistor
What is battery disconnect unit BDU (12v harness?)

Are you talking about the resistor inside the Service disconnect?


Take the removable section (1) off, walk over to your workbench, and measure resistance across main pins 1 and 2 with a multimeter set to resistance. If it is less than 10 Ohms, it's fine. If it is greater than 10 ohms, it is bad and you should replace it.

[NORTON]

.....
Have you had the opportunity to access the high voltage service disconnect under the rear seat (after disconnecting 12V battery) and disconnect that as well?..

Thanks so much for posting all this info.
It is encouraging to see an independent shop doing this kind of repair!

One question: How do you release the rear bottom seat cushion to get access to the disconnect?
I thought I'd ask instead of 'rip and tear'. In the vid it is already pulled.

Thanks again.

[Infinion]

.....
Have you had the opportunity to access the high voltage service disconnect under the rear seat (after disconnecting 12V battery) and disconnect that as well?..

Thanks so much for posting all this info.
It is encouraging to see an independent shop doing this kind of repair!

One question: How do you release the rear bottom seat cushion to get access to the disconnect?
I thought I'd ask instead of 'rip and tear'. In the vid it is already pulled.

Thanks again.

It's actually a fairly straightforward process. On each end of the seat there is a plastic snap fitting / retainer that can be non-destructively removed by taking a flat pry tool and applying moderate leveraged force to pry the fitting loose.

Here is a video of an owner doing such a process.

https://www.reddit.com/r/SparkEV/commen ... rear_seat/

The service manual glosses over this detail for accessing the HV service disconnect, which is disappointing to say the least. But if you dig deep enough you can find the relevant information, like this page of the Rear Seat Cushion Cover and Pad Replacement.



Viewing this image, I'm starting to think that removing the cup holder brackets is the most convenient way of accessing the HV service disconnect.