weird problem please help
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weird problem please help
I have a 2012 f250 diesel. Yesterday I started it up and was waitin for the wife and it started to idle up and the fan shut on and off. I pulled away and all the power shut off like someone pulled the battery cables off but the engine stayed running,no dash lights ,gauges nothing except the heater went to full 12 volt on the blower. I shut the key off and turned it on and all came back on....it did this twice,then the battery light came on and stayed on and idle is higher than normal and I think its the fan turnin on and off. I checked the voltage and it gives 14.85 volts....I plugged my code reader in and it gives p0000 code twice. Any help would be great ty in advance
Fleet Owner
Joined: Mar 2012
Posts: 20,167
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From: Wisconsin
That seems to be too high of voltage (even on a variable output system). I had a voltage regulator go out in my alternator and it overcharged everything and it caused a lot of damage. I'd encourage you to have someone that knows what they are doing (a Ford service tech) look at it.
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ty savage
I agree on the voltage I suspected that may of been the problem and it was kicking things off for protection or something. I have an app. for Thursday morning but I was just gonna try to get the jump on it....ty for the reply I will let you know the outcome Thursday night.....maybe lol
Lead Driver
Joined: Apr 2011
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From: Edmonton Alberta
Mine did something very similar.....
Battery light on and generator putting out about 14V continuously.
Dealer threw a whole bunch of parts at it, new alternator, new PCM ... can't remember what else.
Turned out the "gencom" wire, see attached, the yellow wire between the PCM and generator was broken. (my truck has a lot of bad wiring and this is the third or 4th wire that has broken due to bad routing and no protection).
Pinpoint Test C: DTC P0620
Refer to Wiring Diagrams Cell 12 , Charging System for schematic and connector information.
Normal Operation
The PCM monitors the generator output via the generator monitor (GENMON) circuit. The PCM uses the generator command (GENCOM) circuit to command the generator to either increase or decrease output. If the GENCOM circuit (generator control circuit) or the "A" sense circuit are open or shorted to ground, the PCM will not be able to control the generator output. When the engine speed is greater than approximately 2,000 rpm, the generator defaults to a steady voltage output of approximately 13.5 volts and the PCM sends a message over the High Speed Controller Area Network (HS-CAN) to the Instrument Panel Cluster (IPC) through the Body Control Module (BCM) to illuminate the charging system warning indicator lamp.
DTC P0620 (Generator Control Circuit) — The PCM sets this DTC if the GENCOM circuit or "A" sense circuit is open or shorted to voltage or ground.
This pinpoint test is intended to diagnose the following:
Fusible link
Wiring, terminals or connectors
Generator
PCM
Battery light on and generator putting out about 14V continuously.
Dealer threw a whole bunch of parts at it, new alternator, new PCM ... can't remember what else.
Turned out the "gencom" wire, see attached, the yellow wire between the PCM and generator was broken. (my truck has a lot of bad wiring and this is the third or 4th wire that has broken due to bad routing and no protection).
Pinpoint Test C: DTC P0620
Refer to Wiring Diagrams Cell 12 , Charging System for schematic and connector information.
Normal Operation
The PCM monitors the generator output via the generator monitor (GENMON) circuit. The PCM uses the generator command (GENCOM) circuit to command the generator to either increase or decrease output. If the GENCOM circuit (generator control circuit) or the "A" sense circuit are open or shorted to ground, the PCM will not be able to control the generator output. When the engine speed is greater than approximately 2,000 rpm, the generator defaults to a steady voltage output of approximately 13.5 volts and the PCM sends a message over the High Speed Controller Area Network (HS-CAN) to the Instrument Panel Cluster (IPC) through the Body Control Module (BCM) to illuminate the charging system warning indicator lamp.
DTC P0620 (Generator Control Circuit) — The PCM sets this DTC if the GENCOM circuit or "A" sense circuit is open or shorted to voltage or ground.
This pinpoint test is intended to diagnose the following:
Fusible link
Wiring, terminals or connectors
Generator
PCM
Official Ford Rep
Joined: Oct 2010
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I agree on the voltage I suspected that may of been the problem and it was kicking things off for protection or something. I have an app. for Thursday morning but I was just gonna try to get the jump on it....ty for the reply I will let you know the outcome Thursday night.....maybe lol
Crystal
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From: Wisconsin
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