93 V6 fuel pressure release.

[sgould]

Light went off in mid-June.  I put a bottle of Forte injector cleaner in last Wednesday before we set off on holiday.  All was well until mid-afternoon today when he engine light came on again and the P0463 fuel gauge fault appeared.  Only one fault registered, and I knew the gauge/sender were faulty, but I pressed the wrong button on eSID and it did the check again and got the same code plus the P0089 one too.  

I've cleared it and it stayed off for the rest of the day. Almost the whole day was cruising at 70/80 mph on the German autobahn from Wuppertal to Braunschweig.  Around four hours of driving.

[sgould]

Light is still off after another few hundred miles.  Fingers crossed.

I also played with some of the other functions on eSID and it tells me that the most I/we have demanded from the performance is 403Nm torque and 297hp.  I don't believe it can tell that much really, but it suggests that there's not much wrong with the engine (fingers crossed again!!) as the factory spec is 400Nm and 280hp.

[carrera]

It's actually quite easy to get that information, Trionic works as follows:

There's a Mass air request, from your right foot, measured in grammes per combustion IIRC
Then using a conversion it's assumed that the air will have the correct amount of fuel injected, which will give a torque number (again IIRC it's mass divided by 3.1)
Power is then just a mathematical derivation of torque

Units of measure are important when moving beyond method 

[aerojon]

The V6 is Bosch ME9.6.

[carrera]

Fair point, I should really take more note of the car he's talking about.

However, the engineering principles are common

[sgould]

Uncrossed fingers too soon.  The P0089 engine light came on again today.  I've turned it off again.

[sgould]

During the German trip P0089 appeared a couple of times.  I cleared it with the eSID.  But there were no issues with running.  On the last day we came back to the German border on a quieter autobahn.  I tried a couple of full throttle runs, one with the Sport button pressed, one without.  Both runs lasted 20 seconds or so before a slower car got in the way and the car got to around 140mph, briefly.  There was no hesitation or any noticeable misfires, so I think the basic fuel system is fine. 

So it seems to point to an issue with the pressure sensing system rather than the fuel itself.

[aerojon]

Taken from a 2013 thread on the 2.8 V6 F.Pumps on S.Central ..Installing a 9-3 FWD V6 Fuel pump in a 9-3 XWD for P0089
MODELS:
2006-2009 Saab 9-3 XWD
With B284 Engine Only
CONDITION/CONCERN:
A technician may need to replace a fuel pump in an XWD vehicle and they are not
available. They may also find DTC P0089 (Fuel Pressure Regulator Performance) with
no performance or running issues. The vehicle will exhibit no other DTC. The WIS
diagnostics may lead to fuel pump replacement. This DTC may also set when the fuel
in the tank runs out.
This diagnostic trouble code is generated if the ECM thinks the pump/system capacity
is less than expected or if it had to command a higher PWM voltage to the fuel pump
control module than the modules predetermined map. If the ECM has requested a
certain fuel pressure and for whatever reason the Fuel Rail pressure sensor does not
report the requested pressure back to the ECM or if the PWM current is too high this
dtc p0089 may set. This could be caused by the module, wiring or any issue that may
affect perceived fuel pressure or delivery. This could include low fuel pressure from a
bad fuel pump, leaking fuel injector or pressure sensor orifice that is restricted due to
debris in fuel rail, very low fuel level or high current draw from the pump.
RECOMMENDATIONS/INSTRUCTIONS:
If DTC P0089-Fuel Pressure Regulator Performance is found with no other running
issues or DTC’s do NOT replace the fuel pump unless low fuel pressure is observed
while testing the fuel pump pressure per WIS. If the desired/commanded fuel pressure
is the same as the requested fuel pressure, do NOT replace the fuel pump.
In cases were no fuel pressure issue can be found and DTC P0089 is set, please
replace the Fuel Pump Control Module before replacement of the fuel pump.

[sgould]

That is a really useful link.  Thanks!