P2D07

Code

Generic P — Powertrain

Motor Electronics Coolant Pump B Underspeed

Brand: Generic

Type: P — Powertrain

Views: UK: 30 EN: 34 RU: 28

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Low or intermittent supply voltage to pump or pump controller
Faulty pump motor (worn brushes, damaged windings, seized bearings or impeller)
Mechanical blockage in pump or coolant circuit (debris, collapsed hose, frozen coolant)
Airlock in coolant circuit reducing flow/load characteristics
Faulty motor speed/position sensor or missing feedback signal
Damaged wiring, poor connector, open/short in control or feedback circuit

Symptoms

Reduced coolant flow or reduced system pressure
Elevated engine or battery coolant temperatures
Heater performance degraded (reduced cabin heat or delayed warm-up)
MIL/CEL illuminated; DTC P2D07 stored
Possible limp or reduced performance modes on hybrid/EV systems
Noise from pump (grinding, whining) or no audible pump operation when commanded

What to check

Read freeze frame and full failure data with a scan tool (commanded vs actual speed, duty, voltage, current)
Visual inspection of pump, wiring, connectors, fuses and relays for damage or corrosion
Check coolant level and signs of contamination or debris
Inspect hoses for kinks, collapse or blockage and verify radiator/heat exchanger flow
Listen for pump operation while commanding pump with scan tool
Measure supply voltage to pump during command and compare to expected

Signal parameters

Command input: PWM duty 0–100% (typical PWM frequency 200 Hz–2 kHz) or analog command 0–12 V depending on design
Supply voltage: typical 12 V systems expected 11–15 V under load; some systems use high-voltage motors—refer to service manual
Feedback: hall sensor, open-collector or tachometer frequency or 0–5 V speed signal; expected present when motor spinning
Typical pump speed range: vehicle dependent — commonly hundreds to several thousand RPM; verify expected RPM from manufacturer data
Current draw: increases with mechanical load; compare measured current to known-good values

Diagnostic algorithm

Retrieve DTCs and live data. Record commanded pump speed/duty, actual speed/feedback, supply voltage and current during fault conditions.
Perform visual inspection: coolant level, pump housing, connectors, wiring chafing, fuses/relays. Repair obvious damage.
With ignition ON (follow safety for HV systems), command pump ON using scan tool while observing supply voltage, command duty and feedback. Note if pump runs and speed response.
If no feedback/speed but command present, probe feedback circuit (voltage or frequency). Inspect/repair sensor wiring or replace sensor if missing/erratic.
Measure voltage at pump power pins while commanded. If voltage absent or low, trace to fuse/relay/power supply and repair wiring or control module output.
If voltage present but pump underspeeds, check current draw. High current suggests mechanical bind or shorted motor; very low current may indicate open windings or internal motor failure.
If possible, remove pump and bench-test on appropriate bench supply to verify mechanical operation and actual speed under controlled conditions (observe safety and manufacturer guidance if high-voltage motor).
Inspect impeller and internal pump for debris, corrosion or seized bearings. Clean or replace pump assembly as required.
If pump and wiring test good, evaluate and test the pump controller or module and PCM output. Reflash/update software if a known fault exists per service information.
After repair, clear codes and perform a road or system test to confirm normal operation and that actual speed matches commanded values across operating range.

Likely causes

Electrical supply problem or connector corrosion to pump
Mechanical resistance (impeller seized, debris or collapsed hose)
Failed/weak pump motor (internal fault)
Bad speed/feedback sensor or loss of feedback signal to controller

Fault status

⚠️ Status

Coolant Pump B running slower than commanded. Check pump supply, wiring, controller and mechanical condition. May cause reduced coolant circulation and elevated temperatures.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.5 - 3.0 hours