EN

Severity: Moderate Code type: Generic (all makes)

P0627 Code: Fuel Pump "A" Control Circuit/Open

The PCM's fuel pump command line has no complete circuit – a dead relay coil, open wire, fuse or module.

At a glance

Severity: 3/5 – Moderate3/5

Severity: Moderate

Meaning
Fuel Pump "A" Control Circuit/Open
System
ECU & Outputs · Powertrain
Safe to drive?
With caution
Typical repair cost
$20–$1,600
DIY difficulty
Moderate

The PCM never feeds the fuel pump directly; it drives a control output that switches a relay or tells a fuel pump driver module how fast to run the pump. The driver inside the PCM watches the voltage and current on that output, and P0627 means it found an open: no load is connected where a relay coil or module input should be. That happens when the relay coil has burned open, the relay or its fuse is missing or loose, a connector has backed out, or the wire has broken somewhere between the PCM and the relay box or module. Unlike P0628 and P0629, nothing is shorted – the circuit is simply interrupted, so the pump usually doesn't run at all when the fault is present. Some makers use P0627 and P0230 for the same circuit.

Can I keep driving? If the car starts and runs normally, you can drive it gently to a shop, but the fault can return without warning and stall the engine. With an intermittent open, avoid highways and heavy traffic, and don't let the tank run low.

How to read P0627

How to read P0627P10263274
  1. P Powertrain
  2. 0 Generic (SAE)
  3. 6 Computer & outputs
  4. 27 Specific fault

Symptoms

  • Crank but no start – no hum from the tank when the key is switched on
  • Engine stalls while driving and restarts after sitting or tapping on the relay box
  • Hard starting in wet or cold weather when a corroded connection opens up
  • Check engine light, sometimes with a loss-of-communication code for the pump module
  • Car runs normally but the code keeps returning as history

Possible causes

Ranked by how often each cause is behind this code (editorial estimate).

  1. Relay coil burned open, or the relay loose or missing from its socket 26%
  2. Broken control wire or backed-out terminal between PCM and relay or module 22%
  3. Fuel pump driver module unplugged, corroded or failed input 18%
  4. Blown fuse on the relay coil feed 14%
  5. Internal relay failure in an integrated power module or fuse box 12%
  6. Open driver output in the PCM 8%

Diagnosis step by step

Diagnostic flow: P06271Run the pump from the scan tool2Find out what the PCM actuallydrives3Measure the whole loop from the PCMend4Check for voltage at the PCM pin5Confirm the pump side with a fusedjumper6Wiggle-test and inspect connectors

  1. Run the pump from the scan tool

    Use the scan tool's output test to command the pump on while someone listens at the fuel filler neck. Many PCMs also show a control-circuit status PID; 'open' confirms the fault is present now, which makes it much easier to find than an intermittent one.

    Tools: OBD-II scanner

  2. Find out what the PCM actually drives

    Check the wiring diagram: a relay in the underhood box, a relay built into an integrated power module, or a separate pump driver module near the tank or spare tire. The test points and the likely failure differ for each design.

    Tools: Flashlight

  3. Measure the whole loop from the PCM end

    With the key off and the PCM connector unplugged, measure from the fuel pump control pin to the relay coil's feed fuse. You should read the coil resistance, typically about 60–120 ohms. An infinite reading means the open is in the coil, the fuse, a connector or the wire – split the circuit at the relay socket to find which.

    Tools: Multimeter

  4. Check for voltage at the PCM pin

    Reconnect everything, key on, and back-probe the control pin while the PCM is not commanding the pump. On most low-side designs it should sit at battery voltage through the relay coil; 0 V means the path back to the fuse is broken.

    Tools: Multimeter

  5. Confirm the pump side with a fused jumper

    With the relay removed, bridge the socket's switch terminals (usually 30 and 87) with a 15–20 A fused jumper for a few seconds. If the pump runs, the pump and its feed are fine and the problem is purely on the control side. Never leave a jumper in place.

    Tools: Pliers

  6. Wiggle-test and inspect connectors

    Flex the harness at body pass-throughs, the rear frame connector and the module plug while watching the status PID or listening for the relay. Clean corroded pins, restore terminal tension and seal connectors that sit in spray from the road.

    Tools: Flashlight, Multimeter

Where the parts are

EVAP system: gas cap, canister, purge and vent valves – P0627123456
EVAP system: gas cap, canister, purge and vent valves
  1. 1Gas cap
  2. 2Charcoal canister
  3. 3Purge valve
  4. 4Vent valve
  5. 5Fuel pump
  6. 6Intake manifold

Repair options & costs

RepairDIY?Estimated cost
Replace fuel pump relay or fuse Yes $20–$90
Repair broken control wire or terminal No $120–$350
Replace fuel pump driver module No $180–$500
Replace integrated power module / fuse box No $600–$1,400
Replace PCM with programming No $700–$1,600

Rough US estimates for parts and labor; shop rates vary by region. Not a quote.

Notes by brand

Dodge

On many Dodge, Chrysler and Jeep models with a TIPM, the fuel pump relay is built into the power module. When that internal relay fails you get intermittent crank-no-start and fuel pump control codes; replacing or repairing the TIPM is the usual fix.

Ford

Ford trucks and SUVs that use a fuel pump driver module often mount it on the frame or near the spare tire, where road salt corrodes the module and its connector. Inspect it before blaming the PCM.

P0627 on Ford in detail

Volkswagen

Many VW group models use a separate fuel pump control unit under the rear seat on top of the tank. Check its connector and power supply when fuel pump control codes appear together with a no-start.

Field data

Ford 7

Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.

Emissions / smog test impact

Will fail

P0627 sets the check engine light, so the car fails an OBD smog check until the circuit is repaired. After clearing the code, drive through a few normal trips so the readiness monitors complete before the test.

Frequently asked questions

How is P0627 different from P0230?

Both point to the control side of the fuel pump, not the pump motor. P0627 specifically means the PCM sees an open circuit on its fuel pump output, while P0230 is a broader 'primary circuit' fault; some manufacturers set one, some the other, for the same broken wire or relay.

Will a new fuel pump fix P0627?

Almost never. The code is about the PCM's command reaching the relay or driver module. Prove the pump runs with a fused jumper across the relay socket before spending money on a pump.

Why does the car start after tapping the fuse box?

A relay with a cracked solder joint or a loose socket terminal can open and close with vibration. Tapping reconnects it for a while. That behavior is a strong clue, and the relay or the fuse box terminal is usually the part to replace.

Can I just swap the fuel pump relay with an identical one?

Yes, borrowing an identical relay from another circuit such as the horn is a quick test on vehicles with plug-in relays. If the code and no-start disappear, replace the relay; if not, move on to the wiring.

Sources