DL380 G7 (possible?) firmware bug causes fans to peg at 78%

[BuzzC]

I'm running into an interesting issue.  DL380 G7 starts up just fine, but as soon as the OS hits, fans peg at 78% 100% of the time.  It seems like there may be some problem with temperature sensor 29.  Here is what iLo shows during post:

Notice that Temp 29 is not installed.  If I stall the boot process anywhere, the fans ramp down to about 18%.  But once the OS hits (and I have tried various flavors of Linux including Ubuntu 16.04 and RHEL7, no Windows Server yet...):

And hplog -t shows it as SCSI backplane:

ID TYPE LOCATION STATUS CURRENT THRESHOLD
1 Basic Sensor Ambient Normal 59F/ 15C 105F/ 41C
2 Basic Sensor Processor Zone Normal 104F/ 40C 179F/ 82C
3 Basic Sensor Processor Zone Normal 104F/ 40C 179F/ 82C
4 Basic Sensor Memory Board Normal 66F/ 19C 188F/ 87C
5 Basic Sensor Memory Board Normal 68F/ 20C 188F/ 87C
6 Basic Sensor Memory Board Normal 68F/ 20C 188F/ 87C
7 Basic Sensor Memory Board Normal 66F/ 19C 188F/ 87C
8 Basic Sensor System Board Normal 77F/ 25C 194F/ 90C
9 Basic Sensor System Board Normal 69F/ 21C 149F/ 65C
10 Basic Sensor System Board Normal 75F/ 24C 194F/ 90C
11 Basic Sensor System Board Normal 68F/ 20C 158F/ 70C
12 Basic Sensor System Board Normal 78F/ 26C 194F/ 90C
13 Basic Sensor I/O Zone Normal ---F/---C ---F/---C
14 Basic Sensor I/O Zone Normal ---F/---C ---F/---C
15 Basic Sensor I/O Zone Normal ---F/---C ---F/---C
16 Basic Sensor I/O Zone Normal ---F/---C ---F/---C
17 Basic Sensor I/O Zone Normal ---F/---C ---F/---C
18 Basic Sensor I/O Zone Normal ---F/---C ---F/---C
19 Basic Sensor System Board Normal 62F/ 17C 158F/ 70C
20 Basic Sensor System Board Normal 66F/ 19C 158F/ 70C
21 Basic Sensor System Board Normal 68F/ 20C 176F/ 80C
22 Basic Sensor System Board Normal 69F/ 21C 176F/ 80C
23 Basic Sensor System Board Normal 69F/ 21C 170F/ 77C
24 Basic Sensor System Board Normal 68F/ 20C 158F/ 70C
25 Basic Sensor System Board Normal 66F/ 19C 158F/ 70C
26 Basic Sensor System Board Normal 68F/ 20C 158F/ 70C
27 Basic Sensor I/O Zone Normal ---F/---C ---F/---C
28 Basic Sensor I/O Zone Normal ---F/---C ---F/---C
29 Basic Sensor SCSI Backplane Normal 134F/ 57C 140F/ 60C
30 Basic Sensor System Board Normal 96F/ 36C 230F/110C

Any ideas why a temperature sensor would not be there during POST but would show up after OS initialization?  But most importantly, how do I get the fans to behave normally?

Edit:

Should include versions:

Power Management Controller 1.6

CPLD - PAL0 ProLiant DL380 G7 System Programmable Logic Device version 0x0F 

System ROM P67

iLo 1.87 Oct 27 2015 

[BuzzC]

Post failed to include my second image.  Here is what iLo shows temperatures after OS initialization:

https://imgur.com/a/jzQyi

[Torsten.]

Temp 29 is too high (60 degrees = critical). Any non HP disks installed?

This might be caused by a problem in sensor reading, a disk may not support this.

[BuzzC]

There are three Seagate disks installed.  I have read of problems with HDD firmwares incompatibilities with whatever the internal BIOS is trying to read.  If I read the temperatures from the S.M.A.R.T. tools, it reports a much more acurate temperature.

The question becomes, why does it say sensor 29 not installed during POST but then misread it during OS initialization?

And why, with all the many problems that have been reported about this, is there no option to disable reading it in BIOS?  The wasted power draw from the fans running 78% all the time should have the green people sharpening pitchforks...

[BuzzC]

The oddness continues.  Sensor 29 seems to vary in it's temperature reading with every boot.  Last night it was reading 50 C, which is 10 degrees below the caution threshold of 60 C.  Yet still the fans pegged at 78%.

Is there no chance of getting any support from HP on this problem/bug?  It seems fairly wide-spread.

[Oscar A. Perez]

One of your HDD is reporting higher than normal temperatures? iLO3 gets HDD temperature readings directly from the Smart Array controller after POST is completed.

Are these HP drives?  If so, check if the drives have the latest firmware available and also upgrade the P410i controller firmware to the latest.

If the issue persists after that, I would try isolating which one of the HDDs is causing the issue.