P027B: Invalid pump B control data has a specific feedback signature

P027B identifies invalid fuel pump B control data in Ford's documented returnless-fuel strategy. The controller receives a diagnostic status from the pump module; the result is not a direct fuel-pressure measurement.

Recognize the feedback message

Ford assigns a fuel-pump-monitor duty cycle of 20 percent, plus or minus four percentage points, to this invalid-data result. Nearby rows use different feedback information for a secondary-circuit fault, an internal module error and missing communication. The percentage therefore represents a status category, not the pump's physical output.

Retain the incoming control request and returned monitor signal together. Without that pairing, a stopped pump could be mistaken for a failed motor even when the module is responding to an invalid command.

Keep pump B separate from pump A

The source lists P025B for pump A's invalid-data result and P027B for pump B. The base code's channel identity is important when a vehicle has more than one pump-control path. Do not infer component location or interchange modules from that letter alone.

Ford lists continuous operation within entry conditions, an 11–16-volt battery window and a two-to-five-second monitoring duration. Verification needs valid command/feedback behavior without recurring invalid-data status. The summary does not establish whether the initiating problem lies in a command source, wiring or the module, and it supplies no universal replacement instruction.

Source and applicability

This explanation covers the cited Ford monitor variants, not every vehicle displaying this code. Match the engine, sensor architecture and calibration before applying numerical limits.

Ford OBD summary, PDF page 141.