OBC Hack Question

[seventythree]

I just finished the hack and only have partial functionality!
Two of the wires allow me to scroll back or forth through the basic information, i.e., outside temp, fuel mileage, average speed and so on. But the other two wires don't do anything, hence, I can't bring up the OBC menu to check or configure any of the features.
I enabled the OBC using the Durametric cable and software.
Before I go and start checking for faulty connections, am I missing anything here? Do I not understand how the OBC works, or did not fully activate it using the Durametric?

TIA

[ronster]

Not sure if this is what else you're looking for but try it.

To access diagnostics:
Hold down the Recirculating & Air up buttons for 5 seconds. The + - buttons go up and down through the list of "c" codes. The center vent button switches the left display between the "c" code and its actual value. Press the Auto button to exit.

0c - ERL
1c - Oil Temp?
2c - Inside temp. Sensor mounted in the aspirator assembly at the side of the dash.
3c - Outside temp. Sensor located inside the air inlet of the A/C unit.
4c - Outside temp. Sensor located in front grill of the radiator. The data is fed to the Climatronic from the instrument cluster. When not moving, the instrument cluster OBC temp display retains it's last setting until moving. This is to prevent heat emanating from the radiator affecting the temp. sensor. The A/C unit uses the lower of the two outside air temp values in determining fresh-air temp.
5c - Outside temp. (matches with OBC outside temp display)
6c - Coolant temp.
7c - Foot well discharge temp.
8c - Sun sensor (dash top)
9c - Sun sensor.
10c - Passenger compartment fan speed.
11c - Passenger compartment fan voltage.
12c - Temperature mix Flap command 1=COLD, 100=HOT
13c - Temperature mix Flap position
14c - Central Flap command
15c - Central Flap position
16c - Foot well/Defrost Flap command
17c - Foot well/Defrost Flap position
18c - Recirculation Valve command 1=OFF, 100=RECIRC
19c - Recirculation Valve position (feedback)
20c - Vehicle speed in kph, updating only once per second. (real speed, not speed+safety margin as in the speedometer)
21c - Engine RPM in hundreds. This too only updates once per second.
22c - ?
23c - ?
24c - Sun sensor, exterior lights switch & panel lights control (term. 58 & 58d voltage) - used for A/C panel display illumination.
25c - ?
26c - ?
27c - ?
28c - Fan speed?
29c - ?
30c - Engine run time in seconds (255 max.)(=0xff)
31c - Timing counter
32c - Displays test
33c - Software version? (Some say 3.4, what does your say?)
34c - ?
35c - Outside temp. from inlet sensor (filtered?)
36c - temp?

[seventythree]

Thanks ronster. Although not what I was looking for, this is fabulous information that I will archive for future reference.

Now, as an update to my inquiry:
Actually, I just drove the car for the first time after the hack and all four wires are performing their basic function, i.e., scroll up, scroll down, reset and speed gong.

However, I just can't turn on "Display A" as referenced in the Owners Manual! What is with that? Can people with the 4th stalk do this? I can think of the following possibilities:

1) The factory wiring for the OBC is more involved than the hack, hence, the hack provides limited functionality.

2) The 4th stalk is more that a simple SPQT (single pole quadruple throw) switch. In other words, it does more than just short one of 4 signal wires to ground. If so, does anyone have the switching diagram for it?

3) What I got is all there is to the OBC and the factory illustrations are not applicable.

Any and all input would be appreciated.

TIA

[ronster]

I did the OBC hack about a year ago on my '99 Boxster and get the same readouts you do. What does your manual say about "Display A?" I don't find it referenced in mine.

[seventythree]

My Owners Manual, starting page #92, talks about a display section A in the instrument cluster which can be turned on by pushing the stalk out toward the floor. Once display A is on, one can scroll through different settings, including checking & resetting fault codes.
My car is 2002 base.

[ronster]

Originally Posted by seventythree

My Owners Manual, starting page #92, talks about a display section A in the instrument cluster which can be turned on by pushing the stalk out toward the floor. Once display A is on, one can scroll through different settings, including checking & resetting fault codes.
My car is 2002 base.

I'll recheck my manual again on that page. It could have been a change in 2000 when some of the base 986 changes took place.

Just to update I checked my manual and on pages 66-67 the OBD hack for a '99 does not include a display A. To have the fault codes and reset feature for them is way cool.

[seventythree]

These are some pages out of my 2002 manual.
I am starting to think there is more to wiring the OBC that what is indicated in the so called "hack". If I had a wiring diagram, I am sure I could figure it out.

[ronster]

You might try a Bentley's manual they have the wiring diagrams and would probably show how the stalk is wired then you could at least isolate where the wires go. If you installed a switch I'm not certain that it will do everything the stalk will do though. Good luck, let us know how it goes.

[Hatzenbach]

To answer seventythree's first question:
The four basic functions provided by the four wires are:
* Up/Down (scroll through trip computer / temperature / dist to empty / MPG)
* Set the chime to ring at a certain speed (you first enter this mode and then set the desired speed with the up / down buttons)
* Cancel / Reset (for that you must press the button for like 3 seconds)

Now about the OBD in the Boxster clusters
The original cluster was made by Motometer and was available until (as far as I know) 2001 and had a small and very basic LCD display.
With the 2002 model Porsche switched to a (very similar looking) cluster made by VDO for both the 986 and 996 (the 996 Turbo got the newer cluster with the 2001 model)
The VDO cluster had bigger areas for the LCD and as far as I know had a more basic LCD module in the 986 and more fancy in the 996 (which had a full blown dot matrix pixel display).
The 986 display had two rows of numbers:
mileage on top
trip computer / temperature / dist to empty / MPG on the bottom

So far I was under the impression that the "fancy" display which has three rows (where the bottom one is bigger) was only available in the 996 but apparently I was wrong.
Nevertheless, have first a look at the elements in your center LCD display. If you see distinct elements like you would see in a digital clock, then you have the "simple" display, if you can not see distinct elements, then you have the more fancy dot matrix display which should be able to display all of the features in your manual.

Oh yes, and I should mention that I got all the functions in seventythree's manual to work in the 996 cluster in my car with the four wires from the OBC hack.

[seventythree]

Bingo! Hatzenbach's response puts the whole thing in perspective:

- There are two types of instruments clusters for 986 Boxsters, basic and dot matrix.
- The basic cluster provides basic OBC functionality, where the dot matrix provides full functionality as indicated in Owners Manual pages above.
- If a Boxster was equipped with the OBC option from the factory it was fitted with the dot matrix cluster.
- Boxsters without the OBC option were fitted with the basic cluster.

I am sure everyone can deduce the rest for themselves.