P26EA

Code

Generic P — Powertrain

Fuel Pump Control Module B

Brand: Generic

Type: P — Powertrain

Views: UK: 20 EN: 36 RU: 18

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Page language: EN

Causes

Open, short, or intermittent wiring between PCM and Fuel Pump Control Module B
Corroded or poorly connected connector(s) at the fuel pump module or control module
Failed Fuel Pump Control Module B (internal electronics)
Failed fuel pump or pump motor (load or short condition)
Blown fuse or faulty relay for pump or control module power supply
Low battery voltage or poor chassis/engine ground

Symptoms

MIL (Check Engine Light) illuminated
Engine cranks but may not start or has extended cranking
Intermittent or poor engine performance (hesitation, stalling)
Low or fluctuating fuel rail/line pressure
Fuel pump may not run or may run continuously
Related drivability faults under load or at key-on

What to check

Retrieve freeze frame and live data with a scan tool; note fuel pump command/duty, fuel pressure, battery voltage and related codes
Visually inspect wiring, connectors and in-tank module for corrosion, water intrusion or damage
Verify fuses and relays for fuel pump and module power circuits
Check battery state of charge and charging system voltage
Back-probe connector pins and measure power, ground and control signals at the Fuel Pump Control Module B
Measure static and dynamic fuel pressure and compare to spec

Signal parameters

Battery supply voltage to module: nominal battery voltage (approx. 11–14.5 V with engine off/cranking/running)
Control signal from PCM: PWM duty 0–100% (expected varies with commanded fuel pressure/load); frequency typically tens to a few hundred Hz depending on vehicle
Ground continuity:
Module output to pump: switched power near battery voltage when commanded on
Fuel pump current draw (typical range varies by pump design) — significant increase indicates pump or shorted motor
Fuel pressure: static and running values per vehicle spec; pressure should rise to commanded rail/line pressure when module is active

Diagnostic algorithm

Read and record all codes, freeze frame, and live data. Note battery voltage and fuel pressure at time of fault.
Inspect harness/connectors at fuel pump module, junctions and PCM for corrosion, damage, rodent chew or loose pins. Repair as needed.
Check fuses and relays for pump and module power. Replace any blown fuses and verify relay operation.
With key ON (engine off), back-probe the module power and ground pins. Confirm battery voltage at power pin and good ground at ground pin.
Command fuel pump ON with scan tool (if supported) and observe module output voltage and fuel pump operation. Check fuel pressure response.
If pump does not run but module has power and command signal present, measure module output to pump. If no output, suspect module or internal fault.
If module outputs but pump does not run, measure pump motor resistance and current draw. Replace pump if out of spec or stalled.
Use an oscilloscope to verify PCM control waveform (duty cycle and frequency) to the module if voltage testing is inconclusive.
If wiring checks good and module behaves inconsistently, disconnect battery, replace or repair the Fuel Pump Control Module B per manufacturer procedure, then clear codes.
After repairs, clear codes and perform a full system test (multiple key cycles and a road test) to confirm fault does not return. Re-scan for pending codes.

Likely causes

Damaged or corroded connector/harness to fuel pump control module B
Loss of power or ground to the control module (blown fuse or bad relay)
Internal failure of Fuel Pump Control Module B
Open or short in the control signal (PCM to module) or pump power feed
Fuel pump motor drawing excessive current due to mechanical or electrical failure

Fault status

⚠️ Status

PCM detected abnormal condition in Fuel Pump Control Module B circuit — open/short/invalid response or out-of-range output causing incorrect pump operation.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours