I have owned my '05 STR for nearly 1 year, and have had a few problems, namely:
#1.. (Red light) Coolant low, after a small recirculation top hose burst,
#2.. (Red light, limp home) TPS problem after a massive rainstorm,
#3.. (Yellow light) Performance restriction, after intercooler coolant pump failed.

Thanks to this forum I was able to learn about these problems, but then I wanted to know more about internal signals and error codes. When I saw that forum member Avos had good things to say about the ODBII Ultragauge, cost about $70, I got one.

Manual has to be downloaded, and is quite complete. When plugged in, Ultragauge identified the STR's protocol as 9141, and found 50 available gauges.

The next thing was to set up the pages of information display. Ultragauge can display up to 7 pages of information, with each page showing 4, 6 or 8 different gauges. Pages can scroll after any time interval you choose. I started off with 8 gauges per page, but even after a 60-second scroll time soon discovered the true meaning of the expression "information overload". Impossible to drive and check all that info at the same time!!

So, in the end, I set up only 3 pages, each with 4 gauges, showing the info I was really after (pics below):
Page 1 (60-second display) from top left clockwise shows IAT2, Coolant temp, timing advance and boost pressure.
Page 2 (20-second display) shows Short and Long Term fuel trims.
Page 3 (20-second display) from top left clockwise shows Sensor voltage Bank 1 and Bank2, current system voltage and Ultragauge operating temp.

Power-On detect was set to mode 2 (checks for a threshold voltage of 13.2 volts.).
Power-Off detect was set to mode 3 (checks 5 times for RPM < 512). Be warned, I originally set Power-Off to mode 0 and, because the Jag does not completely shut down electrically for some time after the ignition is off, Ultragauge detected residual OBDII activity after I left the car, did not power off and began to run the battery down overnight.

Works just fine, all gauges have (optional) audio alarms for min and max values of each gauge, and also for Trouble Codes and Pending Trouble Codes. All codes can be recalled and cleared.

 

I have been thinking of getting the Ultraguage also and was wondering how you mounted it in your car. I went a cheaper route and bought a Bluetooth OBD2 adapter on eBay for $16 and downloaded Torgue on my phone.

 

After a LOT of trial and error and bad language, here's how I finally did it. The wires can be just about pushed out of sight.

 

Robinb, are you routing the cable through the steering column?

 

I've seen those and recommended them but have the Scan Gauge II myself.

 

First things to check are LTFTs (see below) are within 5% or so.

Just for comparison, AE (AutoEnginuity) uses CAN (much faster) and has I guess a few hundred values across all the modules. Costs much more, though.

 

I've used the UG for some time on my Landrover and Mercedes. But I'm still head-scratchin' with it on the STR. (See here for my initial comments)

I notice that your Boost PSI also reads a negative #. Any idea why that is?

And your LTFT and STFT: are they reading with what you would expect to see? Mine weren't. the LT's were changing every 3-5 seconds, and they were not within the 5% mentioned above, either.

Are yours?

In short: I'm not yet convinced of the compatibility between the UG and the STR.

 

It's probably got the wrong coding for boost. Does it say what PID it uses?

Sounds like it's messing up LTFT

Can you add custom PIDs?

PID = parameter ID; each is a number used to request a kind of data from the PCM

 

It is probably reading engine vacuum. In my experience the MAP sensor in these engines is to measure vacuum, and does not measure boost accurately. If you want to measure boost you need to add a sensor and a separate gauge.

 

To answer your questions & comments...

The cable fits nicely in the cracks between the cladding on the dash and also down the outside of the steering column. Just about invisible all the way down to the ODB port.

I took the pictures when the engine idling, so the boost was negative (-14.6 psi is a total vaccuum). With no load on the engine, the boost never really gets much above 0 psi (atmospheric pressure), even when the engine is revved. It's only when the engine is under load and the supercharger begins to spin that the boost begins to rise. Go to the bottom of a long straight hill and WOT and you'll see. The Jag is so powerful that at 9 psi (the approx. limit of the Eaton S/C) the Ultragauge must be in or near your line of vision if you want to check the boost without endangering your life.

Engine had not fully warmed up when pictures were taken. At idle, STFT's were showing 0.00. Once on the road, at steady speeds, all fuel trims showed values in the range -5% to +5%. Updating was set for every 2 seconds, but could possibly be set for 1 second since I am using just a few gauges.

No mention of PID's in the manual.

LTFT's settled down once I was on the road, but did not keep steady. Don't know why - on my next long trip I will keep an eye on them.

The Ultragauge claims that the vehicle's protocol is 9141, apparently not very efficient. The CAN protocol is supposedly only available in "Most 2008 and newer" models.

 

It's also available on all STRs (& lots of other 2003+ S-Types) but needs somewhat special software to handle it. It's usual for OBD tools to find the 9141 and just use it. Although it's lots slower it probably doesn't matter for ordinary use.

 

I thought our cars made 13.1 psi stock, so I wonder why you are only seeing 9.

 

He is reading engiine vacuum, not boost.

 

Rasputin, you are correct, I did say that the max boost was around 9 psi for an STR, but I did see somewhere that the Eaton produces 13 psi in an STR. Soon I'll know for sure.
WhiteXKR is also correct, the pic on my first post is actually showing a partial vacuum of -9 psi.

 

I'll be interested to see what you get. My UltraGauge read -15 or so at idle, and at full boost it only got up to about -2. that's a ~13psi difference, but still read as a vacuum.

 

The MAP sensor in the car is not designed to read boost properly, just vacuum.

 

But what is the purpose of a MAP (Mean Average Pressure) sensor in a supercharged car if it only measures vacuum?

 

It is actually Manifold Absolute Pressure.

Even the non-supercharged V8s have the MAP sensor.

It is actually somewhat uncommon for engines to have both a MAP and a MAF (mainfold airflow) sensors. Usually it is one or the other. They are both used to measure air volume, but in different ways.

My guess is Jaguar uses both as a failsafe, so one can check the operation of the other to find faults, and to provide the ability to operate in limp-home mode when one fails with minimal effect on performance.

 

hmmmm, I think the MAP is "Manifold Absolute Pressure". And it is a different gauge on the UltraGauge, pulling the reading from a different sensor than the "Boost Pressure" shown on the UltraGauge.
The MAP gauge on the UG (for the short-time I had it plugged-in) showed (IIRC) about an 8psi swing, in the positive-range, but it did not seem to correlate to when I thought I should be building boost (ie: throttle load)

As I say: I'm still unconvinced that the UG and the STR are compatible. You'll note that UG doesn't list Jaguar in their compatibility pages.
I'd love to find out I'm wrong.... since I already HAVE the UG.

 

You guys have now got me thinking...

I did see that Jaguar was not included in the Ultragauge list of compatible cars, but thought "what the hell, Avos said it was OK".

So, I went to the Internet and found this:
A working Jaguar MAP Sensor is necessary to maintain mandated federal pollution levels. Information about the manifold absolute pressure, which is given by the Jaguar MAP Sensor, is imperative for delivering the right quantity of gasoline into the cylinders. A failing Jaguar MAP Sensor can often cause a decline in your vehicle's fuel economy and multiply engine emissions.

Now I can't be sure just what the reported "boost pressure" really is measuring on the Ultragauge display.