P2B62: Coolant Pump B Supply Voltage Circuit

P2B62 flags a supply voltage problem at coolant pump B, an electrically driven auxiliary pump with its own electronics. Ford's 2024 gasoline OBD summary files it as failure type 1C (supply voltage outside its permitted band) under base code P261A, in the check of pump B, which Ford defines as the high-temperature-loop auxiliary pump for component cooling #1. The check runs continuously, needs at least 11 V battery voltage and has a monitoring time of 5 seconds. Typical triggers are a blown fuse, a weak relay, corroded power or ground pins or a discharged battery. Faults on the control line are reported separately by P261A to P261D, the same supply fault on pump D by P2B69. With insufficient voltage the pump slows or stops, and the component it cools may overheat.

Symptoms

• Warning lamp with stored code
• Auxiliary pump runs slowly or not at all
• Rising temperature of the component cooled by pump B

Most likely causes

• Pump fuse blown or supply relay not closing properly
• Corroded or loose power or ground connection at the pump
• Weak battery or charging system fault lowering supply voltage
• Voltage detection inside the pump electronics faulty

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 P2B62 means

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

Frequently asked questions

Can I keep driving with code P2B62?

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 P2B62?

The most common causes are: pump fuse blown or supply relay not closing properly; corroded or loose power or ground connection at the pump; weak battery or charging system fault lowering supply voltage.

Related codes

• P261ACoolant Pump B Control Circuit/Open
• P2B63Coolant Pump B Stuck/Stalled
• P2B64Coolant Pump B Control Module Overtemperature
• P2B9DCoolant Pump A Supply Voltage Circuit
• P2B69Coolant Pump D Supply Voltage Circuit

Sources

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

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.