P0625: Generator Field/F Terminal Circuit Low

Is your scanner showing P0625?
No worries. We'll show you what it means and how to deal with it.

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OBD Codex, Administrator

P0625: Generator Field/F Terminal Circuit Low

DIY Difficulty Level
Repair Cost
Can I Still Drive?
Yes (Short-term only)

What Does The P0625 Code Mean?

A stored code P0625 means that the powertrain control module (PCM) has detected a lower than expected voltage signal from the generator field coil circuit. The F simply reiterates the field coil control circuit is at fault.

The field coil is probably most recognizable from its windings which are visible through the vent holes on most alternators. The field coil surrounds the generator armature and remains stationary in the alternator housing. The armature spins inside the field coil which is energized using battery voltage. Each time the engine is started, the field coil is energized.

The PCM monitors the continuity and voltage level of the generator field circuit whenever the engine is running. The generator field coil is integral to generator operation and maintaining battery charge levels.

If a problem is detected in monitoring the generator field circuit, a code P0625 will be stored and a malfunction indicator lamp (MIL) may be illuminated. Depending upon the perceived severity of the malfunction, multiple failure cycles may be necessary for MIL illumination.

P0625 wiring diagram

P0625 wiring diagram

What Are The Symptoms Of The P0625 Code?

Symptoms of a P0625 trouble code may include:

  • Charging system lamp illumination
  • Engine drivability issues
  • Inadvertent engine shutoff
  • Delayed engine cranking
  • Other stored codes

What Are The Potential Causes Of The P0625 Code?

Causes for this code may include:

  • Open or shorted generator field control circuit
  • Blown fuse or burnt fusible link
  • Defective alternator/generator
  • Faulty PCM
  • PCM programming error

How Serious Is This P0625 Code?

A stored code P0625 could result in a variety of drivability concerns, including a no-start and/or dead battery condition. It should be classified as severe.

How Can You Fix The P0625 Code?

A diagnostic scanner, a battery/alternator tester, a digital volt/ohmmeter (DVOM), and a source of reliable vehicle information will be required to diagnose a code P0625.

Consult your vehicle information source for technical service bulletins (TSB) that replicate the code stored, vehicle (year, make, model, and engine), and symptoms exhibited. If you find the appropriate TSB, it may yield helpful diagnostic.

Begin by connecting the scanner to the vehicle diagnostic port and retrieving all stored codes and freeze frame data. You will want to write this information down, just in case the code proves to be an intermittent one. After recording all pertinent information, clear the codes and test drive the vehicle until the code is reset or the PCM enters readiness mode.

If the PCM enters readiness mode, the code is intermittent and will be more difficult to diagnose. The condition, which caused the P0625 to be stored, may even need to worsen before a diagnosis can be made. If the code is reset, continue with your diagnosis.

Use the battery/alternator tester to load-test the battery and make sure that it is sufficiently charged. If it is not, charge the battery as recommended and test the alternator/generator. Follow manufacturers recommended specifications for minimum and maximum voltage output requirements for the battery and alternator. If the alternator/generator is not charging, proceed to the next step in your diagnosis.

Use your source of vehicle information to obtain connector face views, connector pin-out charts, component locators, wiring diagrams, and diagnostic flow charts related to the code and vehicle in question.

Check to see if there is battery voltage on the alternator/generator field control circuit by using the appropriate wiring diagram and your DVOM. If not check system fuses and relays and replace defective parts as required. If voltage is discovered at the generator field coil control terminal, suspect a defective alternator/generator.

Note: The field coil is an integral part of the alternator and cannot usually be replaced separately

Recommended Parts

Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:

>>> CrocSee 250 Pieces - Car Fuses Assortment Kit
>>> Alternator
>>> ECU
>>> Autel Scanner MaxiCOM MK808S
>>> KAIWEETS Digital Multimeter

Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!

Check This Video For Reference

Reference Sources

P0625 Generator Field/F Terminal Circuit Low, OBD-Codes.

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