If your Chevy Volt has encountered the P1FFF – System Isolation / Coolant Level Sensor Fault, preventing it from charging and displaying the "Service High Voltage Charging System (SHVCS)" warning on the instrument cluster, you’re not alone. Below, we’ll explain how to clear this fault code using VXDIAG VCX Nano and ACDelco TIS2Web Service Programming System (SPS).
Possible Causes of P1FFF
This fault can be triggered by several issues, such as:
✅ Coolant leak in the battery cooling radiator
✅ Low coolant level in the reservoir tank
✅ Faulty coolant level sensor
Before attempting to clear the fault code, make sure to fix all mechanical issues, including repairing leaks, refilling coolant, and bleeding the cooling system if necessary.
Failed Attempts to Clear P1FFF
Trying to clear secured high-voltage DTCs using GDS2 does not work. No matter how many times you attempt to clear it, the error remains.
The Only Effective Solution
The only way to clear P1FFF is by reprogramming the "Hybrid Powertrain Control Module 2 (K114B)".
This can be done at a dealership or through ACDelco’s TIS2Web online service, which provides access to SPS (Service Programming System).
Required Tools
✔ VXDIAG VCX Nano OBD2 Adapter (compatible with GDS2 & SPS) - Official website purchase channels for VXDIAG.
✔ A laptop with VX Manager installed (VX Manager is the VXDIAG device management software, available for download on the official website)
✔ ACDelco subscription
Step-by-Step Guide to Clearing P1FFF
1. Purchase an ACDelco Subscription
- Register at ACDelco's TIS2Web portal
- Purchase a Vehicle Programming Software subscription
- Add your VIN (Vehicle Identification Number) to the system
2. Install TIS2Web & SPS Software
- After purchasing the subscription, open TIS2Web
- Follow the prompts to complete software installation
- If prompted to run a Java application, allow it
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If your Java settings are configured correctly, you’ll get an option to Run the Java application:
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Which will lead to an installation process for some TIS2Web software:
- Once the first wizard is done installing, you’ll get a prompt to install some more. Just accept the defaults:
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You’ll be prompted for Administrative rights multiple times and eventually it will say installed successfully. Go ahead and click okay and finally this will bring up the SPS software:
3. Connect VXDIAG VCX Nano
- Plug VCX Nano into the OBD2 port
- Open VX Manager and ensure the device is properly connected
4. Put Your Chevy Volt in Service Mode
- Press and hold the start button for 10 seconds until the car enters Service Mode
5. Start SPS Programming
- Select J2534 VXDIAG as the programming interface
- Choose Replace and Program ECU
- Select Chevrolet Volt and confirm VIN number
6. Reprogram the K114B Hybrid Powertrain Control Module 2
- Choose Programming/Normal
- If your Volt doesn’t have a coolant security lock, select "Without RESS Coolant Tank Update"
- Choose Operating System Update
- Review the update summary
7. Download & Install the Update
- SPS will download the firmware and install it onto the module
- Do not unplug the VCX Nano or turn off your computer during the process
8. Complete the Programming
- Once programming is complete, clear all DTC fault codes
- Turn off the ignition for 30 seconds
- Restart the vehicle and check if the fault code has been cleared
Success! Chevy Volt Charging Restored
After completing these steps, plug in the charger. If everything is done correctly, P1FFF will be gone, and your vehicle will charge normally.
This method helps you avoid expensive dealer fees and allows you to fix the issue yourself.
Additional Tips
✅ Before programming, ensure the cooling system is repaired and coolant is refilled
✅ Use a stable internet connection when accessing TIS2Web
✅ Ensure your car battery has enough charge to prevent programming failure
By following this guide, you can successfully clear the P1FFF fault code and restore charging functionality on your Chevy Volt!
