Battery Light on and codes.

ACFarmer

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My 09 just started kicking on the battery light. Codes I have are P0620, P215A, U0155, P0578 and U3F06. Ive had my ABS light on for a while and I figure some of those codes are for that too. I checked my voltage, was 12.8 with truck off, started truck and it jumped to 13.6 for about a minute and then it jumped all the way up to 16. I'm guessing the alternators are internally regulated. So is the alternator going bad or am I looking at a computer issue that causing it to over-charge? Anybody else had this issue? Need to figure it out as I need the truck to pull a trailer in a couple days. Kind of weird how it charged correctly for about a minute before pegging it out.
 

djr4x4

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P0620 - Generator Control Circuit Malfunction
P215A Vehicle Speed/Wheel Speed Correlation
U0155 Ford - Lost Communication With Instrument Panel Cluster Control Module
P0578 - Cruise Control Multi-Function Input 'A' Circuit Stuck
U3F06- :shrug:Maybe to do with the U0155 code possible..
 

Clifford6.4L

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I had a similar problem with my '08. One alternator was barely working and the other alternator was peaking at 21amps and it ended up killing the batteries. I got them replaced and a month later it started turning on the battery light again and my instrument cluster would turn off as well as the headlights. One of the plugs into one of the alternators was not fully connected. Check the plugs and the wires going into the alternators. If that's not it then I believe the PCM controls the alternators on the 6.4s.
 

Wildman

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The DTC P0620 when the GENCOM circuit or A sense circuit are open or shorted to ground. This DTC can also set when the GENCOM circuit is shorted to voltage.

I would begin by inspecting the generator connector (3 pin) C102A. This connector often gets fatigued from heat and vibration, leading to charging system issues and DTCs. If the connector is worn or damaged, you can purchase a replacement connector pigtail at your local dealer and solder it in.

If you don't find any issues with the connector, inspect the circuits between the generator and PCM and between the battery and generator for any damage, chafing, or improper routing. If no harness damage is found, the suspect root cause is a faulty generator that is internally shorting the command signal sent from the PCM, causing the DTC to set.
 

ACFarmer

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I checked the batteries, both good. Check wiring over quick but I'll have to go back and check the alternator wires coming out of it. What gets me is when you start it, it charges perfectly at 13.5 volts and then after a minute or 2 it kicks way up to 15-16 volts. I can see where it already boiled one battery a little. I forgot, the dash has shut off a time or two since it started all this as well.
 

Clifford6.4L

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That is EXACTLY what was happening to me. Starts fine, start driving for a bit and then it's jumping to 15-18 volts and the instrument cluster would stop working and then come back on. I hope for you it's just a loose or chaffed wire and not a PCM! Good luck and keep us updated!
 

Wildman

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I checked the batteries, both good. Check wiring over quick but I'll have to go back and check the alternator wires coming out of it. What gets me is when you start it, it charges perfectly at 13.5 volts and then after a minute or 2 it kicks way up to 15-16 volts. I can see where it already boiled one battery a little. I forgot, the dash has shut off a time or two since it started all this as well.

The Instrument Cluster (IPC) will power down when voltage exceeds a predetermined threshold, which is typically 15.5V. So the IPC powering down is a symptom, and not anything to do with the root cause.

Try starting the vehicle with the generator connector (3 pin) unplugged. When the generator does not receive a signal from the PCM, it should charge at 13.5V (default voltage). If the charging system voltage increases to 15-16V with the 3 pin connector unplugged, this indicates that the generator regulator is defective. The regulator is internal to the generator, and therefore requires generator replacement.
 

ACFarmer

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Unplugged the 3 pin connector on the back of the alternator. It didn't charge at all then. So I started tracing wires, after twisting it around I found a rubbed through spot right at the plug on one of the wires. So it guessing that's my issue. Next question is, can I get that pig tale anywhere and just cut the old one off and hard wire a new one in? It's bad too close to the plug to fix it with what's there.
 

ACFarmer

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Ah, just reread the replies and saw the above post. Local ford dealer should be able to get it for me then?
 

97f350stroker

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Same thing happened to me when I had my 6.4, I had a thread on here also about it with pics. Ford dealer had the pigtail and it fixed me right up.
 

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