P0C46Hybrid/EV Battery Pack Coolant Temperature Sensor A Circuit Intermittent/Erratic
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- 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.
- What you may notice
- MIL that may go out again for a while
- Jumping coolant temperature in live data
- Likely causes
- LikelyLoose or spread terminal at the coolant sensor connector
- PossibleCorrosion at connector or ground point
- PossibleHarness rubbing or cracked near the battery coolant lines
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €60 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.