There has been a few threads before on this issue and the info that you can obtain via the secret menu. Not all Vec-C's seem to have this menu but would I for one would like to get to the bottom of all of the info in it.
My Vec is a 2005 Pre-facelift 1.8 with CD30 and a Basic display.
Firstly, to get into the Test Mode I do the following.
1: Switch ignition on until lights display on dash.
2: with radio switched on (My CD30 switches on automatically anyway) Press and hold settings until an audible bleep is heard. The radio is now in Test Mode.
3: if you repeatedly press the right hand button under the display, you will cycle through 16 options. This is the button that looks like a bullseye, whereas the one on the left looks like a clock. These are as follows:
11)LCD:36 OC (AS IN DEG C)
14) PI-EHU: OC
15) SENS.: 18.0
16)V: 0 T: 36
To exit test Mode, simply press and hold SETTINGS button until bleep is heard.
Now, I can shed some light on some of these options above.
2,3 and 4) I'm guessing, when the ECU or electronics was manufactured, Software version and installation date of the latest software. As my car was registered 23.02.2005 and certain body parts are date stamped Nov 2004, I'm guessing I might be right on this???
9) When engine running, will flash between None and U (Just the letter U) when Hazard Warning lights switched on.
10) The second 100 fluctuates when the engine is running but always stays above 93. When you switch the lights on, all values drop and dimming the interior dash lights takes down the values further.
11) This value does change, but I don't know what it relates to???
12) is charging voltage /battery voltage. As car was switched off when I typed these, on the move, it registers typically 13.7 volts upwards.
13) is the time the RDS clock updates or was last updated.
15) Seems to be just between 0.5 and 1 degree out from the temperature in the display. I suspect this reading is real time and the one on the cars display takes an average over a pre-determined time.
16) is speed in KM/H then engine temperature. This corresponds exactly to the gauge on the dash when engine is warm. When warming up, the temp on the secret menu seems to warm up quicker!
I'm of the opinion that none of these settings can be modified, so I don't think we'll be ruining our cars and I think the guys on here with colour screens etc will get a lot more info.
Can anyone shed any light on the others????