Alternator voltage charging check

[nardi1974]

Hi everyone.
New to the forum and take it easy.
I have an transit connect 1.8 tdci 2010 that has the battery light on ,tryed to find a way to reset it but not an found any option .I checked the battery and alternator they charging well within limit .engine off 12.2 engine off 14.2v and lights on .
Please can anybody know how to check live data from alternator.
Great forum ,thanks in advance.

[FORScan]

1. Alternator is controlled by PCM, so you should look for alternator PIDs there.
2. If light is on, a DTC code should be read from PCM module. Is any code available?
3. 12.2V when engine is off means the battery is discharged, it should be 12.5V or higher.
4. 14.1V when engine is running is too low. If it doesn't grow with RPM increase, it most likely means some problem with alternator or voltage regulator

[nardi1974]

Thanks for replying but the alternator was checked by my mechanic with proper instrument and was fine ,the battery light was on and off for the last six months but now is permanently on. everything on the van works fine even with the lights on no flickering. If the battery wasn't charging would have gone flat by now and no overheating issues.
I will plug on my ELM327 again and look for alternator PIDs on the PCM module.
The DTC was P0622 Generator field terminal circuit and B9317 Battery voltage high.

[FORScan]

The alternator may have no mechanical faults but electric problems (e.g. one or more diodes in the rectifier bridge may die).

You can check VPWR or similar PID to read module voltage and GENVDSD or similar PID (if available) to see what voltage PCM expects to get. Mismatch between these 2 parameters will indicate a problem. However, it does not give you too much,and you will have to perform land-based diagnostic of alternator anyway. Here are some links that you may find helpful:

http://troubleshootmyvehicle.com/ford/4 ... tic-test-1
http://www.freeasestudyguides.com/elect ... ridge.html

And of course you should check wires/contacts first of all.

[nardi1974]

Thank you Forscan for the information ,will be looking out for this.

[nardi1974]

I did have a go at my van today and found the generator live data which showing that the alternator is charging 13v engine of and 15+V engine on and lights and other power consuming on.but the DTC P0624 is not going anywhere .
I tried to check PCM key on engine running on demand self test but it won't let me continue ,is there anything I can do to make this test work?

[FORScan]

,is there anything I can do to make this test work?

Please check your PM