5.4L 3V 2008 - "genmod_ls" = "fault low" - P0625

[sadexpedition]

Hello, I'm from Germany and I'm working together with an experienced Ford mechanic (specialized in 7.3 Powerstroke) on a Ford Expedition of an acquaintance. It is a Ford Expedition from 2008 with 5.4L V8 3V. It has a gas system installed and the previous owners have made a few messes.

Originally, we were only supposed to overhaul the engine, which we did. The engine now runs like clockwork, only the problem with the battery warning in the instrument cluster (which was there before) remains.

Findings so far:
PCM error: P0625 - low (appears again after approx. 20 seconds after clearing when starting the engine)
“GENMOD_LS” = ”fault low”
“GENMOD_FS” = ”no fault”
“GENMOD” = ”0”
“GENCMD” = ~54%
Battery voltage = 14.2 - 14.4V
Battery symbol/message in the instrument cluster display
Battery indicator needle in the instrument cluster is at approx. 50%

What we have replaced and checked so far:
- A new battery has been installed
- A new alternator has been installed
- All fuses have been checked
- The cable from “GENMOD” and “GENCMD” was checked for continuity (alternator to PCM connector) = continuity present
- The ground points on the alternator were checked
- The DTCs have been deleted several times, P0625 appears again and again

Unfortunately, we don't know what to do now and are hoping for some helpful answers from you.

Many thanks in advance

 

[Yupster Dog]

A new alternator has been installed

One thing to check,
There are two alternators for that vehicle. Does you vehicle have navigation?
With navigation you get the higher amp alternator
without nav you need the lower amp alternator.
wrong one will cause the battery light to be on.

Welcome to the forum.

 

[sadexpedition]

Thank you for your answer.
It is difficult for me to say whether the vehicle has navigation, as a third-party radio is installed.

After your message, I entered the VIN at FordParts and it showed an alternator with part number #GL921 (7L7Z10346B).

The previously installed alternator is a TYC 208444, which is compatible with part number 7L7Z10346B, but there was also the battery message, so we bought a new one.
We have now installed an ACDELCO 3342634A from RockAuto, as it was listed for this vehicle. But what confuses me is that only 88864855 is listed under “Original equipment / alternative part numbers”.

Is there any way we can check whether the TYC alternator that was previously fitted is working properly? If it does work properly, then the fault must lie somewhere else, as this alternator is compatible with #GL921 (7L7Z10346B) according to the manufacturer's specifications

 

[Dennis_H]

It has been a while, but had a similar issue on son's old Escape. Replaced alternator, looked good briefly, but same issue. Turns out new alternator didn't work correctly and had to be replaced again. ( See https://www.expeditionforum.com/threads/alternator-charge-issue-on-escape.48898/ )
You can use forscan to monitor the GENMOD and GENCMD line.

If you want more detail, there is a post over on the forscan forums with pics...

Charging issue with 06 Escape - FORScan forum

 

[vinbonifacio]

Thank you for your answer.
It is difficult for me to say whether the vehicle has navigation, as a third-party radio is installed.

After your message, I entered the VIN at FordParts and it showed an alternator with part number #GL921 (7L7Z10346B).

The previously installed alternator is a TYC 208444, which is compatible with part number 7L7Z10346B, but there was also the battery message, so we bought a new one.
We have now installed an ACDELCO 3342634A from RockAuto, as it was listed for this vehicle. But what confuses me is that only 88864855 is listed under “Original equipment / alternative part numbers”.

Is there any way we can check whether the TYC alternator that was previously fitted is working properly? If it does work properly, then the fault must lie somewhere else, as this alternator is compatible with #GL921 (7L7Z10346B) according to the manufacturer's specifications

Greetings,

I have been struggling with this issues the past 8 months. I would get the battery light warning and check charging system intermittently. The car actually left me stranded while driving for long period. I replaced original alternator with 2 remanufactured alternator 1 from amazon one from local advance auto parts and they were both faulty. I now replaced it with new TYC alternator from Rockauto and so far it has not given me the battery warning yet or charging system issues. I believe some of the reman alternators out there are sitting faulty at the shelves stores. My case was my original alternator was slowly dying and not constantly sending correct volt to the PCM.

Hope you've got it figured it out.