P025B: Fuel Pump Module A Control Circuit Range/Performance

On demand-controlled fuel systems the engine module does not drive the pump itself but sends a pump control module the desired pump output on a separate control line, usually as a duty cycle; the module reports back on a monitor line or via CAN. P025B means pump module A receives a signal, but an invalid command – the duty cycle is outside the valid window or implausible. Ford's module signals this with a 20 % (±4 %) duty cycle on its monitor line; the check runs continuously at 11–16 V over 2–5 s. Whether the warning light comes on depends on the vehicle. Typical causes are contact resistance in the control line or connector that distorts the duty cycle, a poor ground or a faulty module.

Symptoms

• Check engine light (manufacturer-dependent)
• Hard or no start
• Rough idle, surging
• Lack of power from wrong fuel pressure

Most likely causes

• Contact resistance or corrosion in the control line or connector distorting the duty cycle
• Pump control module faulty
• Interference or poor ground between engine module and pump module
• Engine module software or output

What to check, in order

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

1. Check the pump's fuse, relay, and connector
2. Compare the reading with other engine data while varying the engine speed.
3. Replace the filter if it is due for maintenance
4. Compare commanded and actual pressure in live data
5. Measure the pressure with a suitable gauge
6. Check the sensor and regulator before replacing the pump

Good to know

• Repair difficulty: medium
• It affects emissions.

What each character of P025B means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 2: Fuel injection
• 5B: Specific fault in that system

Frequently asked questions

Can I keep driving with code P025B?

Avoid long trips and hard acceleration. If you smell fuel or the car stalls, do not continue.

What causes code P025B?

The most common causes are: contact resistance or corrosion in the control line or connector distorting the duty cycle; pump control module faulty; interference or poor ground between engine module and pump module.

Related codes

• P025AFuel Pump Module A Control Circuit/Open
• P025CFuel Pump Module A Control Circuit Low
• P025DFuel Pump Module A Control Circuit High
• P027BFuel Pump Module B Control Circuit Range/Performance
• P064AFuel Pump Control Module A
• P0627Fuel Pump A Control Circuit/Open

Sources

• law.cornell.edu: 13 CCR 1968.2
• fordservicecontent.com: OBD Operations Summary Gasoline 2020 2023
• newtonnet.co.uk: fordobd2012
• roushcleantech.com: Roush CleanTech Diagnostics Manual DA 8.5.18

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.