P3260 on 2016-2018 Chevrolet Volt: Drive Motor Control Module Fault Guide

What's Unique About the 2016-2018 Chevrolet VOLT

For the second-generation (2016-2018) Chevy Volt, this code is exceptionally well-documented by General Motors. Unlike other vehicles where a module fault code often means expensive hardware replacement, on the Volt, P3260 is most commonly caused by a software anomaly. GM released several service bulletins, culminating in TSB 18-NA-016, confirming the issue and providing a software re-flash as the official, and often only, necessary repair. 🎬 See how a technician performs a GM module software re-flash. This issue also affects the 2016-2018 Chevrolet Malibu Hybrid, which shares the same powertrain components.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Check Engine Light (Malfunction Indicator Lamp or MIL) is on.
• "Reduced Propulsion Power" message on the driver information center.
• Vehicle may lose propulsion, especially at very low speeds (under 3 MPH).
• Possible no-start condition.
• "Shift to Park" message may appear on the dash, though this is a separate common issue, it can be reported concurrently.

Most Likely Causes

1. Outdated Power Inverter Module (PIM) Software 🔴 High Probability GM identified a software anomaly and issued multiple Technical Service Bulletins (TSBs) to address it. This is a known issue specific to this platform and its platform-mate, the Malibu Hybrid.
   How to confirm: A GM dealer or a qualified shop with access to GM's Service Programming System (SPS) can check the current software calibration version on the T6 Power Inverter Module and compare it to the latest version available as specified in TSB 18-NA-016.
   Typical fix: Reprogram the T6 Power Inverter Module (PIM) to the latest available calibration. This is a software-only fix and requires no parts.
   Est. part cost: $0

Rare But Worth Checking

• Power Inverter Module (PIM) Hardware Failure: If reprogramming the module with the latest software does not clear the code, or if the code returns quickly, it may indicate an actual hardware failure within the PIM. This is much less common than the software issue. TSB 17-NA-031 notes that if a customer has experienced multiple occurrences of related faults, a module replacement may be needed after diagnosis. Replacement is a very expensive, multi-thousand dollar repair.

Diagnosis Steps

1. Connect a high-quality OBD-II scanner to the vehicle.
2. Scan all modules for Diagnostic Trouble Codes (DTCs). Confirm the presence of P3260 in the Hybrid Powertrain Control Module (HPCM) and P0AC4 in the Engine Control Module (ECM).
3. Verify the primary complaint is the Malfunction Indicator Lamp (MIL) and that there are no other major drivability issues, aside from potential low-speed loss of motion.
4. Check for applicable Technical Service Bulletins. Specifically, reference TSB #18-NA-016, which supersedes PIC6297A and 17-NA-031 for this specific code.
5. Take the vehicle to a GM dealership or a qualified independent shop with GM programming capabilities.
6. Request the technician to reprogram the T6 Power Inverter Module (PIM) with the latest calibration, per TSB 18-NA-016. The labor operation code for warranty claims is 2881918.
7. Ensure the shop uses a programming support tool (like the EL-49642) to maintain stable battery voltage during the update, as any fluctuation can interrupt the process.
8. If the module has already been updated to the latest software and the code persists, further diagnosis of the PIM hardware and wiring will be required, as per GM Technical Assistance guidelines.

Parts You'll Likely Need

• No parts typically needed — The most common fix is a software update (reprogramming) performed by a dealer, not a physical part replacement. TSB 18-NA-016 explicitly states 'No parts are required for this repair'.
  OEM price range: $0
  Aftermarket price range: $0
• Power Inverter Module (PIM) (OEM #24048514 (supersedes 24275450, 24286539, 24291216)) — In the rare event that reprogramming does not fix the issue, the module itself may have failed and require replacement. This is an uncommon and very expensive outcome.
  Trusted brands: ACDelco (GM Genuine)
  OEM price range: $1500-$2500

Related Codes That Often Appear With This One

• P0AC4 — P0AC4 means "Hybrid/EV Powertrain Control Module Requested MIL Illumination". The Power Inverter Module (where P3260 originates) detects its own internal fault and then sends a request to the main Engine Control Module (ECM) to turn on the Check Engine Light. The ECM then logs P0AC4 to show it's turning the light on because another module asked it to. TSB 18-NA-016 explicitly mentions these two codes appear together.

Technical Service Bulletins (TSBs) & Recalls

• 18-NA-016: The definitive bulletin. It provides reprogramming information for the T6 Power Inverter Module to correct DTC P3260 and P0AC4. It supersedes previous bulletins.
• PIC6297A: Preliminary information that communicated a service calibration for the T6 Power Inverter Module was available. It also noted symptoms of MIL on and propulsion loss below 3 MPH.
• PIC6297: Earlier preliminary information stating that engineering was working on a fix for P3260.
• 17-NA-031: A diagnostic tip bulletin that covered multiple codes, including P3260, and suggested reprogramming the Power Inverter Module as the fix for a first-time occurrence.

Platform-Specific Known Issues

• A known software anomaly in the T6 Power Inverter Module is the primary cause for this code on 2016-2018 Volts, as acknowledged by GM in multiple service bulletins.
• Owner experiences on forums like gm-volt.com and Reddit confirm that a dealer visit for the software reflash is the standard and effective solution. Costs reported by users for this service typically range from $150 to $260.

Mechanic-Grade Diagnostic Values

• Software Calibration Verification — expected: The latest software version as specified by GM's Service Programming System (SPS) for TSB 18-NA-016.. Failure: Any software version older than the one released to fix the P3260 anomaly.
• Battery Voltage During Programming — expected: A stable voltage between 12-14 volts, maintained by a programming support tool like the EL-49642.. Failure: Any fluctuation, spiking, over-voltage, or loss of voltage, which can interrupt programming and potentially damage the module.

Scan Tool Commands That Help

• GDS2 (GM Global Diagnostic System 2): Module Diagnostics -> T6 Power Inverter Module -> Programming and Setup — This is the primary function used to perform the software update (reflash) as required by TSB 18-NA-016 to fix the P3260 fault.
• GDS2 (GM Global Diagnostic System 2): Vehicle DTC Information — To perform an initial scan of all vehicle modules to confirm P3260 is present in the PIM and P0AC4 is present in the ECM.
• GDS2 (GM Global Diagnostic System 2): Hybrid Powertrain Control Module 2 -> Control Functions -> Clear Secured High Voltage DTCs — For some high-voltage related codes, a standard 'Clear DTCs' command is insufficient. This special function may be required to clear persistent faults after a repair, although it is not specifically mentioned for P3260.

Wiring & Ground Locations

• Power Inverter Module (PIM) — On the second-generation Volt (2016+), the Power Inverter Module is integrated into the transaxle assembly under the hood, unlike the first-generation Volt where it was a separate, externally mounted unit.. Knowing the PIM is integrated with the transaxle is critical for service. Access is more involved than for a simple bolt-on component. Any physical inspection or replacement is a major repair.
• G218 — A Body Control Module (BCM) ground point. While specific Volt diagrams were not found, a GM TSB for other models notes G218 can be located behind the dash and that an insulator mat can get trapped between the eyelet and the body, causing a poor connection.. While not a direct cause of P3260, a poor BCM ground at G218 is known to cause a wide range of bizarre electrical issues, including communication faults and modules going blank. If multiple, seemingly unrelated electrical codes are present with P3260, checking major grounds like this is a valid diagnostic step.

Real Owner Repair Stories

• Reddit r/volt user (2018 Chevrolet Volt, 75,000 miles) — A 'Drive Motor Temperature Sensor 5 High Voltage' code was set (not P3260).
  ❌ Tried (didn't work) Diagnosis pointed directly to the PIM.
  ✅ What actually fixed it The dealer diagnosed a failed Power Inverter Module (PIM) and ordered a replacement under the Voltec warranty. The key takeaway for this edge case is the extreme wait time for the part, with the owner waiting over 70 days with no resolution in sight.

OEM Part Supersession History

• 24275450, 24286539, 24291216 → 24048514 — Part revisions are common to address manufacturing improvements, software compatibility, or internal component changes. For P3260, the issue is software, not hardware, so the part supersession is not directly related to the fix for this specific code.

Model Year Variations Within This Range

• 2016-2018: There are no significant hardware differences noted for the Power Inverter Module or its related systems that would affect the diagnosis or repair of code P3260 within this model year range. The primary differences between these years were features like optional Adaptive Cruise Control (2017+), infotainment system updates, and changes to option packages. The TSB #18-NA-016 applies equally to all three model years.