Jump to content
SAU Community

Recommended Posts

Firstly is it even the diagram I should be referring to ? 
My model year is 1990 gtst 

If yes, pin 8 in this diagram is the final variable voltage as per speed going to the solenoid? And also it goes to the consult port for the what ?

I mean that’s what it looks like, but I am not to sure if it could be going to elsewhere?

Also pin 5 says to ecu I have color matched that wire (brown with silver trace dots) it is wire to one of the connectors that engine/ecu harness connects to but the ecu side of that wire has been chopped so don’t know where that should be on the ecu or can I connect this directly to speedo wire going to pin53 on ecu ? It makes sense to me unless ecu is pulsing that signal or is that signal from speedo already pulsed ?

my only hopes are with you @GTSBoy🙃

also is there any proper wiring diagram on here that could help me 

IMG_6490.JPG

The ECU doesn't create the speed signal. It is created at the speedo head. That signal is available to all the CUs on the bus that want it (ECU, TCU, ABS, TCS, HICAS, ATESSA).

On that diagram, I can only assume that the "High speed sensor" is the speed sensor/transmitter in the speedo head, and you can see that that wire reports to both the ECU and the HICAS CU on terminal 6 (I think it's 6 - on the RHS up near the top).

The other wire "to ECU" on T5 must be for some signal from the HICAS to the ECU for some other reason. It might be something to do with PS load idle up, or god knows what else.

  • Thanks 1

I am starting to think it could be your speedo.  I had the exact symptom as described in the flow chart I posted when my speedo cable broke, and my HICAS was untouched.  Is there another GTST local to you that you can perhaps borrow the cluster to test?  It's a fairly quick swap.  

On 15/01/2022 at 11:58 AM, TXSquirrel said:

I am starting to think it could be your speedo.  I had the exact symptom as described in the flow chart I posted when my speedo cable broke, and my HICAS was untouched.  Is there another GTST local to you that you can perhaps borrow the cluster to test?  It's a fairly quick swap.  

It could be, I am yet to check if I am getting a pulsed signal at wire going to pin 53, as in past I took my speedo out, the small device(speed sensor)that creates this signal behind the speedo was all intact and fairly in good condition including wiring and the I did a continuity test from there to wire going to pin53, will update once I have confirmed that. I have been assuming my speed sensor is good I could be wrong though.
 

And I now think hicas could be getting the speed signal independently from the speedo. 

  • 9 months later...

I have a new r33 reservoir 8n ky R32 which means i no longer have the reservoir with oil level switch. Im guessing thats why my steering is now heavy?

 

Sigh, now to trace all the damaged loom back to find the wires for reservoir cap with level switch

Yeh. I have looked at the wiring diagram but doesnt appear as though it is the absence of the level switch that is causing the problem. I am waiting for a mate to pull the plug on the cap and go for a drive. I suspect there is something else astray which is why I reckon I just need to go through all the wiring and see from there. The two obvious ones are the speed input and the actual PS solenoid. Maybe with the engine going in and out and all the fluffing around with oil cooler lines/Accusump etc its been pinched. I don't know. For now I am just channelling my inner 18yr old ex Valiant owner 

 

Super%2BHicas%2BDiagram.PNG.jpg

Super%2BHicas%2BDiagram%2Belectrical.PNG.jpg

Hicas%2BECU%2Bterminal%2Bsignals.PNG

3 minutes ago, Duncan said:

Most often speed input....is your speedo working....those cables like to break after all this time.

Yep, stupid things snap right at the back of the speedo where it changes to plastic. I'm surprised no one has made a fully metallic replacement cable by now.

On 11/1/2022 at 1:33 PM, Roy said:

It could potentially be that r33 ps pumps have lower pressure??.

No.

I will recount my old story where the power wire for my O2 sensor shorted inside the loom and burnt the wiring for the PS solenoid - giving me 100% dead heavy steering. Loom faults are defo a thing!

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


  • Similar Content

  • Latest Posts

    • For once a good news  It needed to be adjusted by that one nut and it is ok  At least something was easy But thank you very much for help. But a small issue is now(gearbox) that when the car is stationary you can hear "clinking" from gearbox so some of the bearing is 100% not that happy... It goes away once you push clutch so it is 100% gearbox. Just if you know...what that bearing could be? It sounding like "spun bearing" but it is louder.
    • Yeah, that's fine**. But the numbers you came up with are just wrong. Try it for yourself. Put in any voltage from the possible range and see what result you get. You get nonsense. ** When I say "fine", I mean, it's still shit. The very simple linear formula (slope & intercept) is shit for a sensor with a non-linear response. This is the curve, from your data above. Look at the CURVE! It's only really linear between about 30 and 90 °C. And if you used only that range to define a curve, it would be great. But you would go more and more wrong as you went to higher temps. And that is why the slope & intercept found when you use 50 and 150 as the end points is so bad halfway between those points. The real curve is a long way below the linear curve which just zips straight between the end points, like this one. You could probably use the same slope and a lower intercept, to move that straight line down, and spread the error out. But you would 5-10°C off in a lot of places. You'd need to say what temperature range you really wanted to be most right - say, 100 to 130, and plop the line closest to teh real curve in that region, which would make it quite wrong down at the lower temperatures. Let me just say that HPTuners are not being realistic in only allowing for a simple linear curve. 
    • I feel I should re-iterate. The above picture is the only option available in the software and the blurb from HP Tuners I quoted earlier is the only way to add data to it and that's the description they offer as to how to figure it out. The only fields available is the blank box after (Input/ ) and the box right before = Output. Those are the only numbers that can be entered.
    • No, your formula is arse backwards. Mine is totally different to yours, and is the one I said was bang on at 50 and 150. I'll put your data into Excel (actually it already is, chart it and fit a linear fit to it, aiming to make it evenly wrong across the whole span. But not now. Other things to do first.
    • God damnit. The only option I actually have in the software is the one that is screenshotted. I am glad that I at least got it right... for those two points. Would it actually change anything if I chose/used 80C and 120C as the two points instead? My brain wants to imagine the formula put into HPtuners would be the same equation, otherwise none of this makes sense to me, unless: 1) The formula you put into VCM Scanner/HPTuners is always linear 2) The two points/input pairs are only arbitrary to choose (as the documentation implies) IF the actual scaling of the sensor is linear. then 3) If the scaling is not linear, the two points you choose matter a great deal, because the formula will draw a line between those two points only.
×
×
  • Create New...