P0CE9Hybrid/EV Electronics Coolant Pump A Control Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- The hybrid controller checks the control line of the electric pump that moves coolant through the power electronics loop, which in GM's Volt and ELR serves the inverter module and the high-voltage charger. GM tables from 2011 to 2016 fail it when the output driver reports an open line or a short to ground or voltage in 16 of 20 samples at 250 ms. The 2019 HPC2 table measures line current instead: below 200 mA or above 3 A while the pump is commanded on, below 120 µA while it is off, for 4 s within a 5 s window. All variants are Type B, two trips. Audi logs P0CE900 on the e-tron and Q8 e-tron in thermal management unit 00C5. P0CEB and P0CEC split the fault into low and high, P0CEA covers pump function. With the pump idle, inverter and charger heat up and power is reduced.
- What you may notice
- Malfunction indicator lamp or hybrid/drive system warning on
- Reduced drive power because inverter and charger temperatures rise
- Charging power reduced or charging interrupted
- Pump not audible after switch-on when commanded via scan tool
- Likely causes
- LikelyOpen or chafed control wire, or corroded connector at the electronics coolant pump
- PossibleFailed electronics in the pump itself, drawing no current or far too much
- RareCoolant loss from a damaged hose letting the pump run dry (Audi e-tron/Q8 e-tron bulletin)
- RareFaulty output driver in the hybrid or thermal management control module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €60 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.