Cause
Air trapped in the inverter cooling circuit
An airlock in the power electronics' cooling loop — the failure that follows work rather than wear. The loop's electric pump cannot push air the way it pushes liquid, so a pocket left behind after a coolant change, a pump replacement or any repair that opened the circuit leaves the loop full by the reservoir and empty where it matters. Some of these systems need a specific bleed procedure or a scan-tool-driven pump cycle to purge properly, and skipping it is how a correct repair produces the same overheating code it was meant to fix.
The tell is timing: inverter temperature or performance codes appearing shortly after any cooling system work are an incomplete bleed until proven otherwise — the corpus's unfinished-procedure argument (P0949, P2176) in hydraulic form.
Typically a moderate job.
Codes this can cause (73)
Codes where this is a likely explanation first, rather than merely a possible one.
- P0A93 Inverter A Cooling System Performance Likely for this code High
- P0C31 Inverter B Cooling System Performance Likely for this code High
- P0C47 Hybrid/EV Battery Pack Coolant Pump A Control Circuit/Open Likely for this code High
- P0C48 Hybrid/EV Battery Pack Coolant Pump A Control Circuit Low Likely for this code High
- P0C49 Hybrid/EV Battery Pack Coolant Pump A Control Circuit High Likely for this code High
- P0C4A Hybrid/EV Battery Pack Coolant Pump A Control Performance Likely for this code High
- P0C73 Motor Electronics Coolant Pump A Control Performance Likely for this code High
- P0C74 Motor Electronics Coolant Pump B Control Performance Likely for this code High
- P0CE9 Hybrid/EV Electronics Coolant Pump A Control Circuit/Open Likely for this code High
- P0CEA Hybrid/EV Electronics Coolant Pump A Performance Likely for this code High
- P0CEB Hybrid/EV Electronics Coolant Pump A Control Circuit Low Likely for this code Moderate
- P0CEC Hybrid/EV Electronics Coolant Pump A Control Circuit High Likely for this code Moderate
- P0CED Hybrid/EV Electronics Coolant Pump A Enable Circuit Likely for this code High
- P0E1A Hybrid/EV Battery Pack Coolant Pump B Control Circuit/Open Likely for this code High
- P0E1B Hybrid/EV Battery Pack Coolant Pump B Control Circuit Low Likely for this code High
- P0E1C Hybrid/EV Battery Pack Coolant Pump B Control Circuit High Likely for this code High
- P0E1D Hybrid/EV Battery Pack Coolant Pump B Control Performance Likely for this code High
- P0E3B Hybrid/EV Battery Coolant Pump Overspeed Likely for this code High
- P0EA7 Auxiliary Cooling System Performance Likely for this code High
- P2B28 Hybrid/EV Battery Pack Coolant Pump A Performance Likely for this code Moderate
- P2B29 Hybrid/EV Battery Pack Coolant Pump A Overspeed - Dry Run Likely for this code Moderate
- P0A01 Motor Electronics Coolant Temperature Sensor A Circuit Range/Performance High
- P0A04 Motor Electronics Coolant Temperature Sensor A Circuit Intermittent High
- P0A3C Drive Motor A Inverter Over Temperature High
- P0A3D Drive Motor B Inverter Over Temperature High
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