P0C46 code meaning
Hybrid/EV Battery Pack Coolant Temperature Sensor A Circuit Intermittent/Erratic
Powertrain system Generic code P0Cxx codes Check engine light
What P0C46 means
P0C46 points to a battery coolant temperature signal that jumps faster than liquid in the loop can physically change temperature. GM's 2019 hybrid tables explain the check: every 100 ms the hybrid controller takes the difference to the previous inlet coolant value, adds up ten of these absolute steps and counts a failure when the sum exceeds 64 °C. Four seconds of failures within a five second window set the code, rated Type B with the MIL on the second trip. The test is suppressed while the hard circuit faults P0C44 or P0C45 are active, so P0C46 usually means a signal that is present but noisy. Loose terminals, contact corrosion or a harness that moves with the battery are the usual causes; wiggling the wiring with live data running helps locate it. Sensor B uses P0CD9.
P0C46 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor0.5 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P0C46
- MIL that may go out again for a while
- Jumping coolant temperature in live data
Common causes of P0C46
- Most likelyLoose or spread terminal at the coolant sensor connector
- PossibleCorrosion at connector or ground point
- PossibleHarness rubbing or cracked near the battery coolant lines
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery pack coolant temp sensor aWiring harnessBms
What each part of P0C46 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. |
| 46 | The exact fault in that area. |
What to do next
- Note P0C46 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 P0C46
What does P0C46 mean?
P0C46 means "Hybrid/EV Battery Pack Coolant Temperature Sensor A Circuit Intermittent/Erratic". P0C46 points to a battery coolant temperature signal that jumps faster than liquid in the loop can physically change temperature. It is a generic code, so it means the same on every make.
Is it safe to drive with P0C46?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P0C46 fail an emissions test?
Yes, it can. P0C46 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 P0C46 to fix?
Difficulty: hard. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P0C46 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.