Jump to content
SAU Community

Gear indicator display


oxford1327
 Share

Recommended Posts

Has anybody successfully worked out how to have an aftermarket gear position indicator for an auto in a stagea?

With the Link dash installation almost complete were having issues getting the gear position to show on dash unit, as the factory dash uses 2 seperate signal types between the box and the ECU, as in it receives a square wave signal and transmits a sine wave or vice versa, so it's not reading and allowing the dash panel to show .

It will also be making it potentially worse being that the trans is a manualised valve body and being Jatco 4th gear is electrically selected as well as the lock-up for converter, so they are switched seperate 

Link to comment
Share on other sites

On 6/6/2022 at 8:05 PM, GTSBoy said:

Just do it calculated off of vehicle speed vs RPM.

We can potentially do that, but what about indication for neutral, reverse,park and converter lock up? And would also like to avoid any more thousands in labour costs for calculating and calibration, am reaching out to Link and Aim(dash manufacturers) to see if they have a work around,but thought there may have been someone that's seen it done in a track,drift or drag car that has a Jatco box???

Link to comment
Share on other sites

I can read it in the Haltech software on my car but it doesn’t work with my factory dash indicator. I’m not really worried about it as I will eventually change to a haltech dash 

Link to comment
Share on other sites

On 6/6/2022 at 5:48 PM, oxford1327 said:

Has anybody successfully worked out how to have an aftermarket gear position indicator for an auto in a stagea?

With the Link dash installation almost complete were having issues getting the gear position to show on dash unit, as the factory dash uses 2 seperate signal types between the box and the ECU, as in it receives a square wave signal and transmits a sine wave or vice versa, so it's not reading and allowing the dash panel to show .

It will also be making it potentially worse being that the trans is a manualised valve body and being Jatco 4th gear is electrically selected as well as the lock-up for converter, so they are switched seperate 

I can look into the wiring tomorrow and see where it picks up the signal if you want

  • Thanks 1
Link to comment
Share on other sites

On 6/6/2022 at 6:58 PM, oxford1327 said:

neutral, reverse,park

There are switches for those, no?

TC lockup could possibly be inferred from rpm vs speed also. If it sits dead bang on the relationship given by the gearing, then TC is locked up. If it is in the "band" available from TC slip around the gear ratio, then it is unlocked.

Link to comment
Share on other sites

On 6/6/2022 at 11:44 PM, GTSBoy said:

There are switches for those, no?

TC lockup could possibly be inferred from rpm vs speed also. If it sits dead bang on the relationship given by the gearing, then TC is locked up. If it is in the "band" available from TC slip around the gear ratio, then it is unlocked.

Yep there are 2 manual switches for 4th gear and lock up, so they're the easiest to solve I spose in comparison, just a bugger that the Link ecu and the Link dash can't bloody read the gear position by themselves, and seems that I'm always the damn guinea pig too, but that's my fault for wanting pretty /shiny things and jumping first....

Link to comment
Share on other sites

On 6/6/2022 at 6:44 AM, GTSBoy said:

There are switches for those, no?

TC lockup could possibly be inferred from rpm vs speed also. If it sits dead bang on the relationship given by the gearing, then TC is locked up. If it is in the "band" available from TC slip around the gear ratio, then it is unlocked.

Can't you snoop the TC lockup solenoid to determine this too?

Link to comment
Share on other sites

On 6/8/2022 at 7:57 AM, joshuaho96 said:

Can't you snoop the TC lockup solenoid to determine this too?

Honestly have no idea with anything that has wires cos I tend to let the smoke out of them, so I leave that stuff to others and stick to mechanical things that I can see what they do and how.....

Link to comment
Share on other sites

The 2 shift solenoids form a 2-bit number which describe the forward gears. But don't assume, 0 is first first gear, and 3 is 4th gear. I think from memory b00 is actually 3rd.  The ECU loom also has wires which are digital states for when central shifter is in reverse, neutral or the forward gears.

Coupled with some microcontroller logic (or lucky you if your ECU is modern and has some flexible inbuilt programmable logic), you could determine what gear is currently active, and drive an LED digit display.

Forget the speed vs rpm method for an auto.

P.S.

From one of my micro programs the solenoid combos are as follow (LSB being solenoid 1)

b00 : 3rd gear
b10 : 2nd
b01 : 4th
b11 : 1st

Link to comment
Share on other sites

On 6/9/2022 at 2:47 PM, zoomzoom said:

The 2 shift solenoids form a 2-bit number which describe the forward gears. But don't assume, 0 is first first gear, and 3 is 4th gear. I think from memory b00 is actually 3rd.  The ECU loom also has wires which are digital states for when central shifter is in reverse, neutral or the forward gears.

Coupled with some microcontroller logic (or lucky you if your ECU is modern and has some flexible inbuilt programmable logic), you could determine what gear is currently active, and drive an LED digit display.

Forget the speed vs rpm method for an auto.

P.S.

From one of my micro programs the solenoid combos are as follow (LSB being solenoid 1)

b00 : 3rd gear
b10 : 2nd
b01 : 4th
b11 : 1st

Cheers, will look into this 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share



×
×
  • Create New...