P0C80: Hybrid/EV Battery Temperature Sensor G Circuit Intermittent/Erratic

P0C80 catches a sensor G signal that jumps around instead of following the slow thermal drift of a large battery. GM spells out the logic in its hybrid tables 18OBDG02 and 19OBDG02: every 100 ms the module sums the absolute changes of the reading across a 10-sample window, a total above 10 fails that window, and 4 failed windows out of 5 set the code as Type B, two trips, provided system voltage exceeds 10.2 V and the battery interface module is communicating. Mitsubishi's Outlander PHEV has no erratic code for this sensor. The value stays inside its valid range, which separates P0C80 from P0C7E and P0C7F; a loose terminal or a cracked conductor is the usual reason. When several sensors on one board jump together, suspect the board or its supply.

Symptoms

• Warning lamp that may come and go between trips
• Jumping sensor G value in live data
• Occasional power reduction

Most likely causes

• Loose or fretting terminal in the sensor G connector
• Conductor cracked inside the insulation, breaking under vibration
• Cell monitoring board with unstable reference or 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. Gently move the wiring with the engine running and watch whether the reading changes.
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 P0C80 means

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

Frequently asked questions

Can I keep driving with code P0C80?

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 P0C80?

The most common causes are: loose or fretting terminal in the sensor G connector; conductor cracked inside the insulation, breaking under vibration; cell monitoring board with unstable reference or ground.

Related codes

• P0C7CHybrid/EV Battery Temperature Sensor G Circuit
• P0C7DHybrid/EV Battery Temperature Sensor G Circuit Range/Performance
• P0C7EHybrid/EV Battery Temperature Sensor G Circuit Low
• P0C7FHybrid/EV Battery Temperature Sensor G Circuit High
• P0C37Hybrid/EV Battery Temperature Sensor F Circuit Intermittent/Erratic
• P0C85Hybrid/EV Battery Temperature Sensor H Circuit Intermittent/Erratic

Sources

• gsi.ext.gm.com: 19OBDG02 Hybrid Diagnostics
• gsi.ext.gm.com: 18OBDG02 Hybrid Diagnostics
• law.cornell.edu: 13 CCR 1968.2

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.