Gearbox switches

[solarman216]

The other day someone asked where the reversing light switch is (could not find the thread) and I mentioned that there are 5 in all one for reverse light one for 4 wheel and did not know what the others did, well just by chance today got Ecu Talk to work on the lappy and there is a switch to register if in gear or not, and I have a feeling that there are two for 4 wheel (cos the disengage is on a spring, lever comes out but gear may stay in till load taken off)so that just leaves one unknown, Rick

 

[AlexD333]

Urm

 

[solarman216]

What do you not understand Alex, Rick

 

[briggie]

quite a self explanatory first post by rick , and I know nuffin about cars

 

[solarman216]

I have always wanted to know why 5 switches on the box and transfer box, so near to sussing them all out, Rick

 

[Sweety]

I wonder if 2 are for the 4WD side of things ie a switch for high ratio & another for low ratio to alter the ECU mapping like more torque for low ratio:nenau but I could be talking a load of cr*p here:lol:doh

 

[solarman216]

I wonder if 2 are for the 4WD side of things ie a switch for high ratio & another for low ratio to alter the ECU mapping like more torque for low ratio:nenau but I could be talking a load of cr*p here:lol:doh

interesting thought, unfortunately the box I have on a chassis with no body so easy access has been robbed of its switches, I will have to get one of my motors up on the hoist and check this out sometime, Oh and as a by thought if any one removes any switches most have balls or extending rollers that are likely to fall out, so great care required, Rick

 

[Sweety]

As I said I could be talking a load of rubbish:augie but my thought was when in low ratio you want mainly torque over BHP but when in high ratio 2 or 4WD your more after BHP over torque. I wonder if the switches are shown clearly in the workshop manual. Hopefully Alex will be able to understand this:lol

 

[Barrbeast]

I reckon could be 3 for the transfer lever - 1 on disengage like Rick says, 1 on High setting and 1 Low setting as I have a feeling the light goes out if you put the transfer box into neutral.

Not convinced by the mapping suggestion - the change in ratio from High to Low already increases the torque :nenau

 

[AlexD333]

I'll be interested to have a look when I next swing by :thumb2

I see what your getting at, but I don't really understand if it's electrical or mechanical and can these switches "go wrong" what would happen if one were to fail?

 

[solarman216]

yep transfer neutral could well be, and re the mapping stuff if I was doing it I would reduce the torque in low box not increasing it as from experience it breaks things, Rick

 

[Thomas-the-Terrano2]

om the y61 trol, it had an sort of hand throttle switch, gave you about 1200rpm
to get car warm, and save you having to feather throttle.

ok well if you moved the main gear stick, think even without dipping clutch, it
knocked the revs down, ie couldnt drive on hand throttle. thinking might expain
one of these switches, dont know if any terranos have come with hand throttle
or button throttle option.

 

[rustic]

... dont know if any terranos have come with hand throttle..

My 1995 MkI Mav has a hand throttle, very useful for steep decents on rough roads, much smoother than trying to keep your right foot in the same place.:thumb2

This knob has often been wrongly described as a choke in previous threads.

 

[Ogri]

On my Tdi, the tick over drops by about 100 rpm after being stationary for a second or two, so maybe a motion sensor?

 

[rayf3262]

There is a vehicle speed sensor on the transmission.
This serves the speedo & then the ecu.
It is correct that the idle speed should drop by 100rpm after being stationery for a second or two.

 

[Banshee]

There is a vehicle speed sensor on the transmission.
This serves the speedo & then the ecu.
It is correct that the idle speed should drop by 100rpm after being stationery for a second or two.

Correctamundo, however I want to know if this is affected by temperature as all summer mine would idle at 900rpm however since its been cold it's been idling at 1100rpm then drops to 1000rpm

 

[rayf3262]

There are 3 temperature sensors:
1) Dash temp gauge only.
2) Engine coolant temp to ECU
3) Fuel temp to ECU

The first you can pretty much ignore.
The second and third are very likely to have an effect on idle speed.
Also, if the aircon is switched on, idle is increased by 100 rpm.

 

[Banshee]

There are 3 temperature sensors:
1) Dash temp gauge only.
2) Engine coolant temp to ECU
3) Fuel temp to ECU

The first you can pretty much ignore.
The second and third are very likely to have an effect on idle speed.
Also, if the aircon is switched on, idle is increased by 100 rpm.

Haha this reminds me of our 1l Polo Pool Car at work and the sensor was broken I think when it went into the garage. If you turned the Air Con on whilst statonary and the engine wasn't up to temp the engine would stall :lol

"German Engineering" :doh