Datatek
Well-Known Member
- Posts
- 44,887
- Location
- Near Poitiers SW France
Let me start by saying that what follows WILL NOT be the answer to all driver pack problems and this post may even be a bit premature.
At the start of this year, My P38 started throwing up the occasional fault:- "Air pressure signal constantly high".
This fault has often been associated with driver pack problems so I swapped the driver pack, after 6 months the problem had not recurred confirming that the driver pack was the likely cause. I'm guessing, but I believe the "Air pressure signal constantly high" is a bit like " Vehicle has moved" in that it's logged when the ECU cannot identify the fault.
So, on to looking at the defective driver pack. It was immediately obvious that there was an area of overheating that had blackened and cracked the potting compound. Unfortunately I didn't take a photo but I knew it was in the position of a 100uf 63V electrolytic.
I dug out the potting compound with care and it was obvious that the electrolytic had been getting very hot at some point. I cut the wires and soldered in a new electrolytic to the short ends of wire left above the PCB and re-sealed it.
Now, I said that this post may be a bit premature, that is because the repair has only been on test for a month or so which may not be long enough. I will update if the failure recurs.
The electrolytic is across the power lines to the driver pack, it's function can be looked at in two ways, as a storage device providing a reservoir of power for solenoid activation, or it could be said it stops voltage fluctuations reaching the EAS ECU and upsetting it, electrical noise in other words.
At the start of this year, My P38 started throwing up the occasional fault:- "Air pressure signal constantly high".
This fault has often been associated with driver pack problems so I swapped the driver pack, after 6 months the problem had not recurred confirming that the driver pack was the likely cause. I'm guessing, but I believe the "Air pressure signal constantly high" is a bit like " Vehicle has moved" in that it's logged when the ECU cannot identify the fault.
So, on to looking at the defective driver pack. It was immediately obvious that there was an area of overheating that had blackened and cracked the potting compound. Unfortunately I didn't take a photo but I knew it was in the position of a 100uf 63V electrolytic.
I dug out the potting compound with care and it was obvious that the electrolytic had been getting very hot at some point. I cut the wires and soldered in a new electrolytic to the short ends of wire left above the PCB and re-sealed it.
Now, I said that this post may be a bit premature, that is because the repair has only been on test for a month or so which may not be long enough. I will update if the failure recurs.
The electrolytic is across the power lines to the driver pack, it's function can be looked at in two ways, as a storage device providing a reservoir of power for solenoid activation, or it could be said it stops voltage fluctuations reaching the EAS ECU and upsetting it, electrical noise in other words.
