P2C67

Code

Generic P — Powertrain

Hybrid/EV Electronics Coolant Pump A Overspeed

Brand: Generic

Type: P — Powertrain

Views: UK: 18 EN: 27 RU: 27

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Faulty pump motor or internal mechanical failure causing uncontrolled speed
Failed or shorted pump speed sensor (Hall or pickup) producing false high pulses
Pump motor controller / inverter or PCM output stage fault commanding excessive speed
Wiring fault (short to voltage) on the speed feedback or command circuit
Calibration or software error in the vehicle control module
Mechanical binding or contamination causing the pump to freewheel at high speed under certain conditions

Symptoms

Malfunction indicator light or hybrid warning lamp illuminated
Coolant temperature warnings or reduced cooling system performance
Unusual pump noise (whine or high-speed whirr) from pump area
Reduced HVAC or battery thermal management performance
Possible limp or degraded power mode depending on manufacturer strategy

What to check

Read freeze frame and live data: commanded pump speed (PWM/duty) vs actual feedback speed
Inspect for related DTCs (communication, inverter, battery cooling) and note occurrence conditions
Visually inspect pump connectors and wiring for damage, corrosion or shorts
Measure supply voltage to pump and ground integrity while pump is commanded
Check speed sensor signal with a scope or lab-grade scan tool (look for pulse frequency and amplitude)
Listen for abnormal pump noise and check for physical contamination or foreign objects

Signal parameters

Control input: PWM command, 0–100% duty cycle; typical PWM frequency range 100–2000 Hz (vehicle-specific)
Feedback: speed sensor output usually a digital pulse or Hall signal; typical amplitude 0–5 V (TTL/Hall) or 0.5–4.5 V
Expected feedback behavior: pulse frequency proportional to pump RPM; verify expected pulses at idle and commanded speeds
Typical pump speed range: 0–several thousand RPM depending on vehicle (consult OEM spec before assuming ranges)
Supply voltage: may be low-voltage (12 V) or high-voltage driven by inverter—confirm system architecture before probing

Diagnostic algorithm

WARNING: Follow all high-voltage safety procedures when working on hybrid/EV systems. Isolate high-voltage system before inspection if required.
Use a scan tool to record freeze frame and monitor live data: note commanded PWM/duty and reported pump speed when the fault sets.
Attempt to reproduce fault with monitored data (engine off, vehicle in READY as safe per OEM procedures). Note conditions (temp, vehicle state).
Visually inspect connectors and wiring on pump, speed sensor, and inverter/controller for damage, corrosion, or signs of overheating.
With proper safety isolation, measure supply voltage and ground continuity at the pump connector while commanding the pump. Look for unexpected overvoltage or loss of ground.
Probe the feedback speed signal with an oscilloscope or good-quality diagnostic tool. Confirm pulse amplitude, frequency and that pulses stop when pump is commanded off.
Check pump motor resistance and insulation (bench test if removed) and inspect bearings/impellers for mechanical faults that can affect feedback.
Test or substitute the pump motor assembly and/or speed sensor if feedback signal is abnormal. If possible, swap with known-good component or perform bench-run test to verify behavior.
If pump and wiring check good, inspect/replace pump motor controller/inverter or address PCM output stage; check for software updates or calibration recalls.
After repair or replacement, clear codes and perform functional/road test while monitoring commanded vs actual speed to confirm fault resolution.

Likely causes

Damaged/contaminated speed sensor producing high-frequency pulses
Control module/inverter commanding full duty due to internal fault
Connector corrosion or chafed wiring shorting feedback to supply
Pump internal failure (bearing loss, rotor slip) causing incorrect feedback
Software/calibration anomaly after service or update

Fault status

⚠️ Status

Hybrid/EV Electronics Coolant Pump A Overspeed — pump feedback speed exceeds allowed threshold; code stored and thermal/cooling strategy may be limited.

🔴 Repair difficulty: Hard

⏱️ Diagnostic time: 2.0-4.0 hours