P0BCF: Generator Inverter Temperature Sensor A Circuit High

P0BCF reports a signal from generator inverter temperature sensor A above its valid range. With the usual NTC thermistor and pull-up, an open circuit, a lost sensor ground or a cracked element drives the voltage up, which reads as an extremely cold inverter. GM's comparable drive motor checks set below -40 to -58 °C and wait until the inverter has worked for about 90 s at 20 Nm or more, so a genuinely cold start does not trigger them. No manufacturer documents P0BCF itself publicly; CARB requires circuit monitoring of hybrid sensor inputs. Until the value is valid the controller uses conservative substitutes and may limit generator power. Check the inverter connectors before replacing the unit.

Symptoms

• Malfunction indicator lamp and hybrid warning
• Reduced generator output
• Implausibly low inverter temperature in live data

Most likely causes

• Open sensor or circuit inside the inverter assembly
• Loose, corroded or unplugged connector at the inverter
• Lost sensor ground

What to check, in order

Start with the simplest. You can tick off each step.

1. Read the codes with a hybrid-compatible scanner and write down the freeze frame data
2. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
3. Make sure the battery cooling air intake is clean
4. Check the 12 V auxiliary battery, which can also trigger warnings
5. Leave any high-voltage measurements to a specialized repair shop

Good to know

• It can trigger limp mode.
• It affects emissions.

What each character of P0BCF means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• B: Subsystem depends on the code range
• CF: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0BCF?

If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

What causes code P0BCF?

The most common causes are: open sensor or circuit inside the inverter assembly; loose, corroded or unplugged connector at the inverter; lost sensor ground.

Related codes

• P0BCEGenerator Inverter Temperature Sensor A Circuit Low
• P0BCCGenerator Inverter Temperature Sensor A Circuit
• P0BCDGenerator Inverter Temperature Sensor A Circuit Range/Performance
• P0BD0Generator Inverter Temperature Sensor A Circuit Intermittent/Erratic
• P0DF6Generator Inverter Temperature Sensor B Circuit High

Sources

• law.cornell.edu: 13 CCR 1968.2
• gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics
• gsi.ext.gm.com: 16OBDG01 Hybrid Diagnostics

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.