P0C70 code meaning
Hybrid/EV Battery Temperature Sensor C/D Correlation
Powertrain system Generic code P0Cxx codes Check engine light
What P0C70 means
P0C70 is the correlation check between battery temperature sensors C and D. The controller expects both to settle at nearly the same value once the pack has rested, and it stores the code when their difference stays too large. No manufacturer documents P0C70 publicly. Where GM and Mitsubishi publish this monitor, they compare each sensor with the pack average and name the single sensor; GM's sensor 4 code P0AE9 is the D counterpart. Before replacing parts it is worth knowing that GM cured false sets of these Volt sensor codes, shown with a battery-too-cold message, by reprogramming the module (18-NA-342). Genuine faults are a drifting thermistor, a sensor that lost contact with its cells, or uneven cooling. The battery controller usually limits power. P0C71 continues with D/E.
P0C70 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 6 hours
- Clears after repairAfter a drive cycle
Symptoms of P0C70
- Malfunction indicator lamp or EV system warning
- Message asking to plug in or warm the battery
- Reduced electric power and slower charging
Common causes of P0C70
- Most likelyThermistor C or D drifted out of agreement with the other
- PossibleBattery control software that sets the code falsely, for example in cold weather
- PossibleSensor C or D detached from its cell group
- Less likelyUneven cooling across the pack, such as a blocked air duct or coolant channel
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery temp sensor cHv battery temp sensor dBms
What each part of P0C70 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| C | Area: hybrid propulsion. |
| 70 | The exact fault in that area. |
What to do next
- Note P0C70 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0C70
What does P0C70 mean?
P0C70 means "Hybrid/EV Battery Temperature Sensor C/D Correlation". P0C70 is the correlation check between battery temperature sensors C and D. It is a generic code, so it means the same on every make.
Is it safe to drive with P0C70?
Drive gently and only to a workshop. With P0C70 the car can go into limp mode (reduced power) to protect itself.
Will P0C70 fail an emissions test?
Yes, it can. P0C70 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0C70 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 6 hours of work. This is a job for a workshop.
Will P0C70 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.