P0C88 is the general circuit code for battery temperature sensor I, chosen when the fault is electrical but not classified as low, high or erratic. No manufacturer documents P0C88 publicly. In GM's Volt pack sensor I is the ninth and last thermistor (bulletin 18-NA-342); the 2012 Volt table 12OBDG01A and GM's later tables cover it only through the specific codes P0C89 to P0C8C. Packs with more sensors, such as Mitsubishi's Outlander PHEV with 50, carry the letter as channel [08]. CARB section (e)(15.3.1) requires continuous range and continuity checks on such inputs. With channel I unreliable, the battery controller falls back to cautious power limits. Older code lists show this number as reserved, so some scan tools may not name it.
High severity. Can I keep driving?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.
Symptoms
- Hybrid or EV warning lamp
- Reduced electric power
- Generic scan tools may show the code without a description
Most likely causes
- Connector fault on the sensor I circuit
- Thermistor I failed
- Defective input channel in the battery sensing electronics
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- It can trigger limp mode.
- It affects emissions.
What each character of P0C88 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- C: Subsystem depends on the code range
- 88: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0C88?
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 P0C88?
The most common causes are: connector fault on the sensor I circuit; thermistor I failed; defective input channel in the battery sensing electronics.
Related codes
- P0C89Hybrid/EV Battery Temperature Sensor I Circuit Range/Performance
- P0C8AHybrid/EV Battery Temperature Sensor I Circuit Low
- P0C8BHybrid/EV Battery Temperature Sensor I Circuit High
- P0C8CHybrid/EV Battery Temperature Sensor I Circuit Intermittent/Erratic
- P0C81Hybrid/EV Battery Temperature Sensor H Circuit
- P0C8DHybrid/EV Battery Temperature Sensor J Circuit
Sources
- law.cornell.edu: 13 CCR 1968.2
- static.nhtsa.gov: MC 10155116 9999
- gsi.ext.gm.com: 12OBDG01A 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.