Charging Sys-Full Description-Trigger Voltages-Test Results

[RangerBill]

@airline tech

Where does the reference line generator desired voltage come from ?
This infernal engine cut I'm getting , relates to intermittent voltage cut on that line

What exactly is happening? Any DTC codes?

Sponsored

 

[colin39]

The PCM (Powertrain Control Module) controls the charging voltage via the LIN communications link. See diagram.

Is there anyway I can upload a video

 

[colin39]

What exactly is happening? Any DTC codes?

No codes , this thing I love but it's cost me a fortune chasing this throttle cut fault

 

[colin39]

What exactly is happening? Any DTC codes?

I'm uploading it to YouTube I'll post a link

 

[RangerBill]

No codes , this thing I love but it's cost me a fortune chasing this throttle cut fault

What throttle cut fault? If you described it earlier in the thread, I missed it. How is it related to the battery charging system?

 

[colin39]

What throttle cut fault? If you described it earlier in the thread, I missed it. How is it related to the battery charging system?

Ok I run a 3.2 diesel with a 6r80 box , it started throttle cutting and calling for neutrals march time, no codes I've narrowed it down to this it kills the voltage and shuts the pcm

 

[colin39]

@airline tech bill take a look please you are the only person on the web to mention generator desired line

Thank you

 

[RangerBill]

@airline tech bill take a look please you are the only person on the web to mention generator desired line

Thank you

I added a description of operation of the charging circuit in my post above with the wiring diagram. I doubt that the charging circuit is causing that. Is your battery voltage in range of 13 - 15 volts?

I couldn't make out anything on your shot of the scan tool. Is the battery symbol coming on just as your engine cuts out? Check power with a voltmeter to the PCM to see if it is losing power. That would cause issues with the engine and battery charging, since both are controlled by the PCM.

 

[colin39]

I added a description of operation of the charging circuit in my post above with the wiring diagram. I doubt that the charging circuit is causing that. Is your battery voltage in range of 13 - 15 volts?

I couldn't make out anything on your shot of the scan tool. Is the battery symbol coming on just as your engine cuts out? Check power with a voltmeter to the PCM to see if it is losing power. That would cause issues with the engine and battery charging, since both are controlled by the PCM.

I have a better video, it's shorter but there is and issue with copyright , radio was on

Today is the first time I've had the battery light flash.

I've also changed the alternator

 

[airline tech]

I am working on a T-Shoot, but I have a question.
If you stay off the throttle - does it, do it?

I suspect either the voltage is dropping off the PCM or a input / output is shorting the PCM and trying to deduce if the Throttle Body or Accelerator Pedal in / out circuit is shorting the PCM out.
I agree the PCM Control module voltage drop is causing the Generator Desired to drop out.

Its defiantly a short or power loss issue, it may be difficult to locate without a code.
It could be the alternator itself or the PWM (control) feeds to it - shorting out as well.

 

[colin39]

 

[colin39]

I am working on a T-Shoot, but I have a question.
If you stay off the throttle - does it, do it?

I suspect either the voltage is dropping off the PCM or a input / output is shorting the PCM and trying to deduce if the Throttle Body or Accelerator Pedal in / out circuit is shorting the PCM out.
I agree the PCM Control module voltage drop is causing the Generator Desired to drop out.

Its defiantly a short or power loss issue, it may be difficult to locate without a code.
It could be the alternator itself or the PWM (control) feeds to it - shorting out as well.

I've changed the throttle peddle and throttle body , tested all the wiring to n from both items and the alternator, the UK only uses a 2 wire unit b+ and a signal to the alternator which is only 8 volts at ignition.

It only fails under load and once hot, today I drove for 3.5 hours before it cut on a junction and nearly killed me. 3 garages have had it and changed all sorts but no fix.
I'm a 38year in the trade spinning spanners kinda guy but I'm at a loss and ford won't help with the wire information regarding that gdv line

 

[RangerBill]

I've changed the throttle peddle and throttle body , tested all the wiring to n from both items and the alternator, the UK only uses a 2 wire unit b+ and a signal to the alternator which is only 8 volts at ignition.

It only fails under load and once hot, today I drove for 3.5 hours before it cut on a junction and nearly killed me. 3 garages have had it and changed all sorts but no fix.
I'm a 38year in the trade spinning spanners kinda guy but I'm at a loss and ford won't help with the wire information regarding that gdv line

Monitor the voltage feed to the PCM and see if it loses power when the issue occurs.

 

[colin39]

Monitor the voltage feed to the PCM and see if it loses power when the issue occurs.

On it in the morning , thanks for your brain buddy.

 

[RangerBill]

I don't think it's the alternator, but you could unplug the LIN connector to it and eliminate that as causing your issue. With it disconnected, the alternator should default to a fixed voltage output.

Sponsored