P2D0A

Code

Generic P — Powertrain

Motor Electronics Coolant Pump C Stuck/Stalled

Brand: Generic

Type: P — Powertrain

Views: UK: 28 EN: 29 RU: 25

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Page language: EN

Causes

Failed or seized coolant pump motor (mechanical seizure or bearing failure)
Debris or foreign object blocking the pump impeller
Open/short in pump power or ground circuit
Corroded or loose connector, damaged wiring, or pin corrosion
Failed pump driver electronics inside the pump or control module
Blown fuse or faulty relay supplying the pump

Symptoms

Malfunction Indicator Lamp (MIL) or warning light illuminated
Reduced or no coolant circulation for the affected circuit
Engine or battery thermal warning / overheating
Unusual whining, grinding, or no sound from pump area when commanded
Heater or HVAC performance degraded (if circuit affects cabin heat)
Related systems log additional codes for cooling or electrical faults

What to check

Read stored/freeze-frame data and confirm P2D0A is set and active
Check whether the pump runs when commanded with a scan tool (bi-directional test)
Listen at the pump location during commanded operation for noise or movement
Visually inspect pump, hoses and surrounding area for debris, corrosion, or coolant leaks
Inspect fuse(s) and relay(s) for the pump circuit; test/replace if suspect
Inspect harness and connector for damage, corrosion, bent pins, or moisture

Signal parameters

Supply voltage to pump: typically close to battery voltage with ignition ON (approx. 9–14 V) — manufacturer-specific
Control signal: often PWM from module; duty cycle varies 0–100% depending on command
PWM frequency range (typical): tens to a few hundred Hz — check manufacturer spec
Expected running current (typical): ~0.5–5 A depending on pump design; stalled or shorted motor may draw higher current
Static motor winding resistance (typical): low ohm value — consult service data for exact ohms

Diagnostic algorithm

Retrieve freeze-frame and live data, confirm code is current and note operating conditions (temperature, ignition state).
Attempt a commanded run of Coolant Pump C via a scan tool while observing pump location: listen/observe if it turns or makes unusual noise.
Visually inspect the pump assembly, hoses and impeller area for blockage, debris, corrosion or external damage. Repair any blockage and retest.
With ignition OFF and battery disconnected, disconnect pump connector and inspect pins for corrosion or damage; repair/clean as needed.
Measure motor winding resistance with an ohmmeter. Compare to service specification. Infinite or very high resistance indicates open winding; very low/shorted is also a fault.
Reconnect battery, measure supply voltage at the pump power pin with ignition ON and while commanding the pump. Verify a good ground. If no supply, trace back to fuse/relay and control module.
If control signal is PWM, use an oscilloscope or a capable scan tool to inspect the waveform and duty cycle while commanding. Confirm control module is commanding and that waveform looks healthy (no excessive noise or missing drive).
Measure current draw during pump command. A stalled motor will show high current and possibly blow fuses; a disconnected/open motor will show near zero current.
If wiring, connectors, fuses and relays are good but pump receives correct command and power yet does not run, replace the coolant pump assembly (or pump motor electronics).
After repair, clear codes, perform pump functional test and road test under operating temperature. Confirm no reoccurrence and that cooling performance is normal.

Likely causes

Pump impeller physically jammed by debris or scale
Pump motor windings shorted or open (internal motor failure)
Connector corrosion at pump harness or pin loss of contact
Driver transistor or MOSFET in pump electronics failed
Supply fuse or relay intermittent/open
Control module command not reaching pump due to wiring fault

Fault status

⚠️ Status

Motor Electronics Coolant Pump C Stuck/Stalled — control module detected the pump motor is not rotating when commanded. Check pump assembly, supply, grounds, wiring and driver electronics.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.5 hours