P2B68: Coolant Pump D Control Circuit High

P2B68 flags a control line for coolant pump D that reads too high: it touches a voltage source or is pulled up while the driver should switch it. No manufacturer documents the code publicly. In Ford's 2024 summary the matching pump A and B codes (P2603, P261D) rest on the same principle, with the smart driver in the engine computer reporting an output circuit fault during a continuous check above 11 V. Likely causes are a wire rubbed through onto a battery-fed conductor, moisture bridging pins or a fault inside the pump electronics. With a line stuck high the pump may run at a fixed speed or ignore commands. Section (e)(15) of CARB 13 CCR 1968.2 wants this kept apart from the open and low faults. Open circuit is P2B66, ground short P2B67, pump E uses P2DF6.

Medium severity. Can I keep driving?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.

Symptoms

Warning lamp with stored code
Pump D runs at a fixed speed or ignores commands

Most likely causes

Control wire shorted to a battery or ignition feed
Moisture bridging pins in the connector
Fault in the pump electronics pulls the line up

What to check, in order

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

With the engine cold, check the coolant level; never do this when the system is hot
Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
Check the actual temperature in live data
Make sure the fan comes on when it should
Check the thermostat and connector
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 P2B68 means

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

Frequently asked questions

Can I keep driving with code P2B68?

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 P2B68?

The most common causes are: control wire shorted to a battery or ignition feed; moisture bridging pins in the connector; fault in the pump electronics pulls the line up.

Related codes

Sources

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.