P2B62: Coolant Pump B Supply Voltage Circuit

What it means

Coolant pump B reports a supply voltage circuit condition. Coolant circulation through the affected loop cannot be commanded reliably.

At a glance

• Usually lights the check-engine light
• The engine or gearbox may go into limp mode

How it works

Coolant pump B circulates coolant through its assigned loop, and its supply voltage circuit provides the electrical power needed for operation. P2B62 sets when the control module detects an abnormal supply-voltage condition for pump B, which can prevent reliable circulation and may trigger reduced-power operation.

Common causes

Most likely first.

1. Supply fuse blown
2. Wiring or connector fault

Symptoms

• Check-engine light
• Engine or a coolant-cooled component may run hotter than usual
• Cabin heat or cooling performance may be reduced

How to diagnose it

1. Check freeze-frame data and live pump B command or status, along with temperatures for the affected coolant loop, to assess whether circulation was lost.
2. With the vehicle safely powered down as specified, inspect pump B's supply wiring and connector for damage, corrosion, or loose contacts.
3. Check the pump B supply fuse and verify power and ground at the pump connector while the pump is commanded, using the wiring diagram.
4. Trace the supply circuit for an open, excessive resistance, or unwanted voltage drop and compare measurements with the manufacturer's specification.
5. If supply and ground are correct but the fault remains, test pump B and its integrated electronics according to the manufacturer's procedure.

Common fixes

• Replace a blown pump B supply fuse after checking for a short or overload that caused it to fail.
• Clean and secure corroded or loose pump B connector terminals.
• Repair damaged or high-resistance supply or ground wiring.
• Replace pump B if it fails testing despite correct power and ground.

Can I keep driving?

Because pump B may not circulate coolant, avoid driving if the engine or affected component is overheating; stop safely if temperature rises. The vehicle may limit power, and continued operation can cause overheating damage.