P1214

Code

INFINITI P — Powertrain

Fuel Pump Control Circuit Malfunction

Brand: INFINITI

Type: P — Powertrain

Views: UK: 0 EN: 0 RU: 1

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Blown fuel pump fuse or faulty relay
Open, shorted or corroded wiring/connector in pump control circuit
Poor or missing ground at fuel pump or control module
Failed fuel pump (motor or internal wiring)
Faulty Fuel Pump Control Module (FPCM) or PCM output driver
Intermittent connection due to vibration or water ingress

Symptoms

Engine cranks but will not start or extended cranking
No or low fuel pressure at fuel rail
Intermittent stalling or loss of power under load
Check Engine Light (MIL) illuminated and possible limp-home behavior
Audible no pump noise from fuel tank when key is turned to ON

What to check

Read freeze frame and DTC data with a scan tool; check for related codes
Attempt to hear fuel pump run when key set to ON (priming) — listen at tank
Check fuel pump fuse(s) and relay operation
Inspect pump connector, wiring harness and ground for corrosion, damage, or poor connection
Measure fuel rail pressure with a gauge while cranking and while commanding pump via scan tool
Use scan tool to command the pump on/off and monitor control PID (voltage, duty cycle, status)

Signal parameters

Battery supply voltage at pump: approximately 11–14 V with engine off/key ON
Control signal: PCM/FPCM may use PWM; duty cycle varies by demand (0–100%) and should change when commanded
Pump current draw (typical range): several amps under normal operation; significant deviation high or low indicates pump or electrical issue
Fuel rail pressure: specification varies by model — confirm expected static and running pressure from service data
Resistance at pump motor terminals (when disconnected): consult service data — an open or near-zero short indicates a fault

Diagnostic algorithm

Safety first: relieve fuel system pressure per service procedure and disconnect negative battery when doing connector repairs.
Verify complaint: attempt key ON priming and observe if pump runs (audible) and check fuel pressure at rail. Record results.
Scan tool: read PCM freeze frame, readiness, and monitor fuel pump control PIDs. Attempt to command the pump ON using the scanner and note response.
Electrical check: inspect fuse(s) and relay. With key ON, verify battery voltage at the pump power supply terminal; expect ~12 V. If no voltage, trace back through relay and fuse.
Connector/wiring inspection: visually inspect the tank connector, pump harness, and chassis ground. Repair any corrosion/damage. Wiggle test connectors while monitoring voltage/current for intermittent faults.
Control circuit testing: back-probe the pump control/PCM output wire. Monitor voltage or PWM waveform with oscilloscope or multimeter while commanding pump. Compare to expected values.
Current draw test: measure pump current while running. Excessive current suggests mechanical binding or short; very low/no current suggests open circuit or failed motor.
Isolate pump: if wiring/power/ground appear correct but pump still fails, disconnect pump and check resistance; consider bench-testing suspected pump or substituting a known-good pump.
Module/PCM test: if harness and pump test good, test or replace fuel pump control module (if separate) or diagnose PCM driver per manufacturer procedures. Use manufacturer wiring diagrams for pin-level checks.
After repair: clear codes and road-test under varied load conditions. Re-scan and verify code does not return and fuel pressure meets specifications.

Likely causes

Corroded connector at in-tank pump or harness chafing
Failed in-tank fuel pump motor causing excessive/low current
Stuck or failed fuel pump relay
Open/short in PCM/FPCM control wire
Battery condition too low to supply pump under load

Fault status

⚠️ Status

PCM detected a malfunction in the fuel pump control circuit (open/short/incorrect voltage or current/PWM), which may prevent proper fuel pump operation and fuel pressure delivery.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1-3 hours

Similar codes

Your experience will help others

+100 karma for a short comment :)

Was this AI description helpful?

Your feedback helps improve AI descriptions.

👍 Like 0 👎 Dislike 0

Send to email

P1214 — Fuel Pump Control Circuit Malfunction