P2B6B: Coolant Pump D Control Module Overtemperature

With P2B6B the integrated electronics of coolant pump D report excessive temperature, and the pump derates or switches itself off to survive. No manufacturer documents this code publicly; the equivalent for pump B is P2B64, which Ford lists as failure type 98 (system over temperature), and for pump A it is P2B9E. Heat in the driver usually builds when coolant around the pump is missing or aerated, when the motor fights a sticking impeller, or when the pump sits close to hot engine or exhaust parts. A failing power stage inside the pump can also trigger the report. CARB 13 CCR 1968.2 (e)(15) covers such output components. Check level, bleeding and free rotation before changing parts. While the pump rests, its circuit gets less flow and may run hot.

Symptoms

• Warning lamp with stored code
• Pump D cuts out after longer operation and restarts after cooling

Most likely causes

• Too little coolant or air at the pump
• Sluggish impeller overloads the motor
• Power stage inside the pump degraded

What to check, in order

Start with the simplest. You can tick off each step.

1. With the engine cold, check the coolant level; never do this when the system is hot
2. Check the actual temperature in live data
3. Make sure the fan comes on when it should
4. Check the thermostat and connector
5. Measure the sensor and replace it if its readings do not make sense

Good to know

• Repair difficulty: medium
• It can trigger limp mode.
• It affects emissions.

What each character of P2B6B means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• B: Subsystem depends on the code range
• 6B: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2B6B?

Watch the temperature gauge. If it climbs or a warning appears, stop the car in a safe place and turn off the engine: overheating can cause serious damage.

What causes code P2B6B?

The most common causes are: too little coolant or air at the pump; sluggish impeller overloads the motor; power stage inside the pump degraded.

Related codes

• P2B6ACoolant Pump D Stuck/Stalled
• P2B6CCoolant Pump D Overspeed/Air in System
• P2B64Coolant Pump B Control Module Overtemperature
• P26F9Coolant Pump C Control Module Overtemperature
• P2DFBCoolant Pump E Control Module Overtemperature
• P2B9ECoolant Pump A Control Module Overtemperature

Sources

• law.cornell.edu: 13 CCR 1968.2
• fordservicecontent.com: OBDSM2400OUTPUT 16Jul2024 WSM final V2 MCS7001

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.