P0705 Code

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As the switch was ruled out and the code is still about it's inputs then two more things can be the problem:
1. the circuit
2. the TCU

for 1 the first suspect is the gearbox loom but in the worst case it can be a wiring issue between that loom and TCU....

2 is simple, you have to replace it
 
sierrafery said:
As the switch was ruled out and the code is still about it's inputs then two more things can be the problem:
1. the circuit
2. the TCU

for 1 the first suspect is the gearbox loom but in the worst case it can be a wiring issue between that loom and TCU....

2 is simple, you have to replace it
Click to expand...
I just pulled a loom out of another 04 discovery and the TCU. I'll try the TCU first than go from there.

Thanks Bub
 
Ok well back to the drawing board. Replaced the TCU and tested the wiring harness. Everything seemed good until after a few miles flashing lights came back on. Cleared the flashing by turning off the engine and waited a couple minutes fired it back up. flashing went away. Started coding again after 5 miles or so. This time CEL came on and coded P0705 once again.
Only thing I haven't done was replace the interior fuse box. I'll do that next. Could this be a BCU problem? I'll report back after I change out the fuse box.

Thanks, Bub
 
Well nothing has changed with the fuse box replaced still getting the M&S lights blinking and than P0705 code.
Especially when I turn on the A/C codes instantly . Not sure where to turn next? Help!!!

Thanks
 
DarthVaderII said:
Well nothing has changed with the fuse box replaced still getting the M&S lights blinking and than P0705 code.
Especially when I turn on the A/C codes instantly . Not sure where to turn next? Help!!!

Thanks
Click to expand...
Unfortunately this is too odd to find a solution remoteley so i cant help more even if i want to, complex troubleshooting is needed done by someone who knows exactly how to read the diagrams to see which headers are shared by both systems and how to rule out a presumed short circuit 😣

aamof try to unplug the aircon unit and see if this helps or not
 
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sierrafery said:
Unfortunately this is too odd to find a solution remoteley so i cant help more even if i want to, complex troubleshooting is needed done by someone who knows exactly how to read the diagrams to see which headers are shared by both systems and how to rule out a presumed short circuit 😣

aamof try to unplug the aircon unit and see if this helps or not
Click to expand...
I was afraid you were going to say that. I'll dig into it deeper but, I won't give up!

Thanks
 

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This started happening this morning . Battery light on voltage dropping below 10.6 with lights , ac, and wipers on . Looks like I may have found my culprit. Alternator/Battery perhaps?
 
Just to be sure, double check the voltage with multimeter on the battery while you get that low voltage reading with hawkeye cos if on the battery is good then it's still a wiring issue somewhere, if it's low on the battery too(maybe a bit higher but below 12) replace the alternator
 
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sierrafery said:
Just to be sure, double check the voltage with multimeter on the battery while you get that low voltage reading with hawkeye cos if on the battery is good then it's still a wiring issue somewhere, if it's low on the battery too(maybe a bit higher but below 12) replace the alternator
Click to expand...
Haven’t been able to reproduce the battery light on with low voltage. I did decide since the serpentine belt needed replacing to do that. I up loaded 3 videos after installing new belt.

1st : engine idling in park no ac on.
2nd : driving with ac on 5 miles
3rd: driving without ac on.

I drove a total of 10 miles no codes whatsoever.

Is it possible changing the belt helped my cause?

exported_91194C31-8470-4F82-9697-F999A615218C.jpeg
 

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DarthVaderII said:
Haven’t been able to reproduce the battery light on with low voltage. I did decide since the serpentine belt needed replacing to do that. I up loaded 3 videos after installing new belt.

1st : engine idling in park no ac on.
2nd : driving with ac on 5 miles
3rd: driving without ac on.

I drove a total of 10 miles no codes whatsoever.

Is it possible changing the belt helped my cause?

View attachment 311572
Click to expand...
It didn’t upload the videos.
 
DarthVaderII said:
It didn’t upload the videos.
Click to expand...

DarthVaderII said:
It didn’t upload the videos.
Click to expand...

DarthVaderII said:
It didn’t upload the videos.
Click to expand...
Since I can't upload videos, the first video would of shown voltage ranging from 14.18-14.48 at idle in park no ac on.

The second would of shown : Driving at 50 mph with ac on nothing else range from 13.97-14.20

The third - driving at 50 mph no ac on range from 14.18-14.38.

Is it typical for the voltage to fluctuate like this in these three scenarios.

Not saying this solved my issue but, it didn't code at all for 10 miles. It was coding with the ac on 2 blocks from my house before the belt change.

Thanks , Bub
 
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DarthVaderII said:
Since I can't upload videos, the first video would of shown voltage ranging from 14.18-14.48 at idle in park no ac on.

The second would of shown : Driving at 50 mph with ac on nothing else range from 13.97-14.20

The third - driving at 50 mph no ac on range from 14.18-14.38.

Is it typical for the voltage to fluctuate like this in these three scenarios.

Not saying this solved my issue but, it didn't code at all for 10 miles. It was coding with the ac on 2 blocks from my house before the belt change.

Thanks , Bub
Click to expand...
Did you change the tensioner at the same time?
 
DarthVaderII said:
I did not. But since you mentioned it I will in the next couple days.
Click to expand...
I get the feeling that when the AC was switched on it asked for more torque necessary to turn it, then maybe it started slipping hence not driving the alternator properly.
If so I am surprised that it didn't squeal.
 
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