Error code · Engine

P1200 — Fuel pump relay circuit malfunction

Don’t put off the repair

For makes: Toyota, Lexus

A fault code doesn’t yet mean the unit or sensor itself is faulty: often it’s the plug and connector leading to it.

Possible causes

What you can do yourself

  1. Check the EFI and fuel pump fuses in the under-hood box.
  2. If the engine won’t start or stalls, go through the “Won’t start” branch in the “Assistant”: it includes a fuel pump check.

Stop and don’t drive on if:

  • The Check Engine light is flashing
  • The temperature gauge is in the red or the overheating light is on
  • The red oil pressure light is on
  • Smoke from under the bonnet, a burning or petrol smell
  • Strong jerking, knocking from the engine, or the car barely moves
OOleg’s tip: check the connector

Often the cause is simple — there is no contact in the connector (plug). Look at the connector from the back: remove the rubber seal and you will see whether a wire is corroded or has come off completely. Corrosion shows up as green deposits. Ideally, gently pull each wire towards you one at a time: a sound wire stays in place, while a corroded one simply comes off — it needs to be repaired.

Unplug and inspect connectors with the ignition off.

This is the Toyota and Lexus meaning. On other makes this number means something else: if your car isn’t a Toyota or Lexus, change the make at the top.

Source: obdadvisor.com (Toyota manufacturer codes)

OA case from Oleg’s practice

  • Toyota Hiace 2018 Won’t start, code P1200 — fuel pump circuit. The pump gets power, but it only ran after a light tap on the module cover — the pump needs replacing. How it went ↗

The explanation comes from the error code reference in the AvtoElektrik PRO app.

Need a mechanic’s help?

Couldn’t fix it yourself? Oleg, an auto electrician, does computer diagnostics and repairs: he comes out anywhere in Almaty or sees you at his workshop.

Want to figure it out yourself?

Oleg’s course “Car computer diagnostics with a scan tool”: how to hook up a scanner, read codes and live data, and use them to find the cause. The first lessons are free.

Scan tool diagnostics course →

Nearby codes

All codes in P10xx–P16xx →

Who keeps this reference

The reference is kept by Oleg Dmitriev, an auto electrician from Almaty with 26 years of experience: computer diagnostics of cars and trucks, repair of control units (ECUs). Can’t find the cause? Message him.