Chevy Volt is a plugin hybrid vehicle produced by General Motors. It is a highly reliable hybrid car if maintained well. However, it is not without issues. One of the most common problems is the Chevy Volt service high voltage charging system message on the DIC screen.
What does this error code mean? How to diagnose it, and what can you do to resolve this error message? I’ll answer all these questions in this article.
What Does Chevy Volt “Service High Voltage Charging System” Message Mean?
Service high voltage charging system message in Chevy Volt means a low hybrid battery coolant level has been detected. Now this might actually be true. However, in other cases, something else can be wrong with the system, a faulty sensor maybe. In either case, you won’t be able to charge the hybrid batteries of your Chevy Volt.
Chevy Volt owners have commonly encountered the error message saying “Service High Voltage Charging System.” Like every hybrid car, there are two charging systems in Chevy Volt. One is the 12 V charging system for the lead acid battery. All the electrical features of your Chevy Volt draw power from this battery. It is charged via an alternator.
The other charging system, referred to as the high voltage charging system, is the one we are talking about here. This charging system is responsible for charging the hybrid batteries of the Chevy Volt. Though electric powertrains require negligible maintenance, there is a need to remove excess heat produced as a byproduct of charging hybrid batteries.
To remove the excess heat, Chevy Volt has a hybrid cooling system in place. This system uses a coolant, a mixture of ethylene glycol and water, also known as anti-freeze. Just like the regular coolant of your car, the level of this coolant can get low over time. This is what triggers the service high voltage charging system message.
How to Diagnose This Message?
Well, there is no need to diagnose the service high voltage charging system message per se as it pops up on the information cluster of your Chevy Volt. But to dig deeper into the cause of this error message, you can run a diagnostic system check.
Here is a list of the most common error codes that may appear on the diagnostic tool:
- DTC P0AA6: Hybrid battery voltage system isolation lost.
- DTC P1AE6: Refers to an issue with the high-voltage battery coolant temperature sensor.
- DTC P1F0E: Battery charging voltage system isolation lost.
- DTC P1FFB: Error with hybrid battery pack coolant level sensor circuit.
- DTC P1FFC: Error with hybrid battery coolant level sensor low voltage circuit.
- DTC P1FFD: Error with hybrid battery coolant level sensor high voltage circuit.
- DTC P1FFE: Hybrid battery pack coolant level is low.
- DTC P1FFF: Coolant level sensor fault.
If either of these codes appears after running a diagnostic test, you can be sure that something is wrong with the high-voltage charging system of your Chevy Volt.
Important: EV battery replacement can cost $1000s. To avoid high-voltage battery replacement, there are some things you can do. Read this article to find out the 10 best ways to maximize EV battery life and save tons of money!
What are the Major Causes of the Chevy Volt “Service High Voltage Charging System” Message?
Low hybrid battery coolant level triggers the service high voltage charging system message. Now the coolant can actually be low, or the sensor monitoring the hybrid battery coolant level might be malfunctioning.
A malfunctioning drive motor battery coolant level sensor can be caused for several reasons. The most common issue is if the sensor gets dirty and cannot read the coolant level properly. It may give a false positive regarding low coolant level.
Another possible cause can be incomplete solder joints within the coolant level sensor. In this case, you will have no choice but to replace the sensor. In the next section, I will explain the process of changing the drive motor battery coolant level sensor in detail.
Also read: Chevy Volt Battery: Warranty, Replacement Cost, Lifespan, etc.
How to Resolve This Message?
The most logical solution to resolve the service high voltage charging system message in Chevy Volt is to top off the hybrid battery coolant. If this doesn’t do the trick, try cleaning the sensor. Or, as a last resort, you will have to replace the hybrid battery coolant level sensor to get rid of this error message in Chevy Volt.
Now, I’ll describe the process of replacing the hybrid battery coolant level sensor of the Chevy Volt in detail. The first two solutions, topping off the coolant and cleaning the sensor, will be automatically covered in this procedure.
So, let’s get started!
Step 1: Preparations
- Before you begin working, wear all the personal protection equipment.
- Park your Chevy Volt on a platform and apply parking brakes.
Step 2: Perform the Diagnostic System Check
- First of all, you need to perform the diagnostic system check.
- To do this, connect a diagnostic tool with the DTC port of your Chevy Volt.
- If DTC P1FFB, P1FFC, P1FFD, or P1FFE are set, proceed to the next steps.
Step 3: Removing the Battery Coolant Level Sensor
- Turn off the vehicle power.
- Remove all keyless entry transmitters from the vehicle and secure them.
- Open the hood of your Chevy Volt and support it with a prop rod.
- Begin by checking the hybrid battery coolant level.
- The hybrid battery coolant reservoir is on the front side of your engine bay.
- Disregard the factory markings to indicate the coolant level.
- Top up the coolant to a point above the reservoir seem
- Perform step 5 of this guide and see if the error is resolved.
- If not, proceed with removing the battery coolant level sensor.
- Remove the front compartment front sight shield.
- Remove the anti-tamper coolant cap bracket and the coolant cap.
- Drain all the coolant filled in the reservoir.
- Remove the drive motor battery radiator surge tank.
- Now you can access the drive motor battery coolant level sensor.
- Remove it using a screwdriver or by opening the pins attached to it.
Step 4: Installing Battery Coolant Level Sensor and Filling Up the Coolant
- Replace the drive motor battery coolant level sensor with a new one.
- Reinstall the drive motor battery radiator surge tank.
- Top off the hybrid battery coolant.
- Inspect the concentration of the coolant mixture using the GE-26568 tester.
- Adjust the surge tank coolant level to a position just above the top of the seam.
- Reinstall the coolant cap and the anti-tamper coolant cap bracket.
- That’s it. You have replaced the battery coolant level sensor.
Step 5: Clear any DTCs
- To finish things off, retrieve the keyless entry transmitters for the vehicle.
- Turn on the vehicle power.
- Attach a scanning tool to the DTC port of your Chevy Volt.
- Clear the unresolved error using the diagnostic tool.
- The error message on the information cluster should be gone.
- Secure the prop rod under the hood and close it.
Is it Safe to Drive Chevy Volt With the “Service High Voltage Charging System” Message?
Yes, normally, driving a few hundred miles with the service high voltage charging system message in Chevy Volt is safe. But you should not ignore it any longer because the error may be caused by a short circuit or twisted wiring harness. This poses a serious fire hazard, or it can destroy the entire charging system of your Chevy Volt.
Service high voltage charging system is a pretty common error message in Chevy Volt. The majority of the time, it is caused by a low hybrid battery coolant level or a malfunctioning coolant level sensor. Either of these cases is nothing to worry about.
But you must be sure about the cause of the error message. Because if these two reasons don’t cause it, something serious might be wrong with the high-voltage charging system of your Chevy Volt. GM has clearly stated that this error message merely indicates a problem with the high-voltage charging system. It doesn’t necessarily mean that the coolant level is low.
So, it is better to be safe than sorry. As soon as you see the service high voltage charging system error message on your DIC, take measures to resolve it immediately.
References
infinitycartips.com, reddit.com, register.nfsb.qc.ca, diag.net, gm-volt.com, chevybolt.org, youtube.com, static.nhtsa.gov