Fault Family System: Powertrain (P-Codes) 35 SAE Codes

Hybrid EV Electronics Coolant Circuit

Diagnostic & Technical Explanation

Code P0CE9 sets when the control module evaluates the hybrid/EV power-electronics coolant circuit as a whole — pump command, flow/level feedback, and resulting inverter/converter temperature trend together — and finds the combined behavior implausible even though no single component sensor has failed its own individual check. The most common physical causes are a system-wide low coolant condition from a slow leak at any fitting in the loop, trapped air that was never fully bled after a service procedure, and a partially clogged radiator or heat exchanger restricting flow across the whole circuit. Because this is a circuit-level plausibility check rather than a single-component fault, diagnosis starts with a coolant level and bleed check before condemning the pump or a sensor, though a handful of codes in this family are plain Control Circuit Low or Control Circuit High faults that point straight at an open or shorted pump or sensor wire rather than a system-plausibility failure.

These 35 diagnostic trouble codes share one detection mechanism and one repair path, which is why MechanicDB groups them into a single authored fault family rather than repeating the same explanation 35 times.

Codes in this family (35)

Code	Definition	Repair coverage
P0CE9	Hybrid/EV Electronics Coolant Pump A Control Circuit/Open	3 ranked fixes
P0CEA	Hybrid/EV Electronics Coolant Pump A Performance	3 ranked fixes
P0CEB	Hybrid/EV Electronics Coolant Pump A Control Circuit Low	3 ranked fixes
P0CEC	Hybrid/EV Electronics Coolant Pump A Control Circuit High	3 ranked fixes
P0CED	Hybrid/EV Electronics Coolant Pump A Enable Circuit	3 ranked fixes
P0CEE	Hybrid/EV Electronics Coolant Temperature Sensor A Circuit	3 ranked fixes
P0CEF	Hybrid/EV Electronics Coolant Temperature Sensor A Circuit Range/Perfomance	3 ranked fixes
P0CF0	Hybrid/EV Electronics Coolant Temperature Sensor A Circuit Low	3 ranked fixes
P0CF1	Hybrid/EV Electronics Coolant Temperature Sensor A Circuit High	3 ranked fixes
P0CF2	Hybrid/EV Electronics Coolant Temperature Sensor A Circuit Intermittent/Erratic	3 ranked fixes
P2B20	Hybrid/EV Electronics Coolant Temperature Sensor B Circuit	3 ranked fixes
P2B21	Hybrid/EV Electronics Coolant Temperature Sensor B Circuit Range/Perfomance	3 ranked fixes
P2B22	Hybrid/EV Electronics Coolant Temperature Sensor B Circuit Low	3 ranked fixes
P2B23	Hybrid/EV Electronics Coolant Temperature Sensor B Circuit High	3 ranked fixes
P2B24	Hybrid/EV Electronics Coolant Temperature Sensor C Circuit	3 ranked fixes
P2B25	Hybrid/EV Electronics Coolant Temperature Sensor C Circuit Range/Perfomance	3 ranked fixes
P2B26	Hybrid/EV Electronics Coolant Temperature Sensor C Circuit Low	3 ranked fixes
P2B27	Hybrid/EV Electronics Coolant Temperature Sensor C Circuit High	3 ranked fixes
P2B2A	Hybrid/EV Electronics Coolant Pump A Overspeed - Dry Run	3 ranked fixes
P2C66	Hybrid/EV Electronics Coolant Pump A Underspeed	3 ranked fixes
P2C67	Hybrid/EV Electronics Coolant Pump A Overspeed	3 ranked fixes
P2C68	Hybrid/EV Electronics Coolant Pump A Stuck/Stalled	3 ranked fixes
P2C72	Hybrid/EV Electronics Cooling System Performance	3 ranked fixes
P2D2A	Hybrid/EV Electronics Coolant Temperature Sensor A/B Correlation	3 ranked fixes
P2E41	Hybrid/EV Electronics Coolant Pump B Control Circuit/Open	3 ranked fixes
P2E42	Hybrid/EV Electronics Coolant Pump B Performance	3 ranked fixes
P2E43	Hybrid/EV Electronics Coolant Pump B Control Circuit Low	3 ranked fixes
P2E44	Hybrid/EV Electronics Coolant Pump B Control Circuit High	3 ranked fixes
P2E45	Hybrid/EV Electronics Coolant Pump B Enable Circuit	3 ranked fixes
P2E46	Hybrid/EV Electronics Coolant Pump B Overspeed - Dry Run	3 ranked fixes
P2E47	Hybrid/EV Electronics Coolant Pump B Underspeed	3 ranked fixes
P2E48	Hybrid/EV Electronics Coolant Pump B Overspeed	3 ranked fixes
P2E49	Hybrid/EV Electronics Coolant Pump B Stuck/Stalled	3 ranked fixes
P2E79	Hybrid/EV Electronics Coolant Pump C Performance	3 ranked fixes
P2E7A	Hybrid/EV Electronics Coolant Pump C Overspeed	3 ranked fixes

What this page does not show

This page publishes the fault mechanism and the code index. The licensed dataset adds, for every one of the 15,886 codes, the full authored repair set (56,729 procedures in total) with the fields deliberately withheld here:

Procedures 2..n after the first-listed procedure
Aftermarket parts cost ranges in USD (est_parts_cost_min/max_usd)
Professional labor-hour estimates (est_labor_hours)
Step-by-step diagnostic and repair instructions
Replacement-part mappings and catalog lookups
6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)

Need All 15,886 Codes as Data?

Pipe-delimited CSV, Apache Parquet and a relational SQLite database, with commercial application rights and instant download. Built for scan tools, shop software and research - not assembled one web page at a time.

License OEM Complete · $149 Standard (SAE only) · $49

$49 Standard: 9,249 SAE codes · $149 OEM Complete: all 15,886 codes, including 6,637 OEM codes across 32 makes · $149 Heavy Duty: 4,212 fault pairs (J1939) · one-time · compare tiers